Implement the following plan:
Create a replicated KV store using Raft consensus, matching the semantics of multipaxos_kv: put fails if key exists, get returns value or error, delete fails if key missing. Client is given leader directly (no leader discovery). The create-emulation skill requires TOML-based configuration.
| MultiPaxos KV | Raft KV |
|---|---|
| Acceptor (voter) | Follower node (AppendEntries responder) |
| Leader (proposer + state machine) | Leader node (log replication + state machine) |
| Replica (passive learner) | N/A - followers apply committed entries themselves |
| Phase 1 (Prepare/Promise) | Leader election (RequestVote) |
| Phase 2 (Accept/Accepted) | Log replication (AppendEntries) |
node.gleam): All Raft nodes are the same type with roles Leader/Follower/Candidateactor.call during request handling (same pattern as multipaxos_kv's Phase 2)CommitNotification to followers so they apply entriesnum_nodes and num_clients from config fileClient --[ClientPut/Get/Delete]--> Leader Node
Leader appends entry to log (term, command)
Leader --[AppendEntries(entries)]--> all Follower Nodes (synchronous calls)
Leader waits for majority of success responses
Leader advances commit_index, applies to local KV store
Leader --[reply]--> Client
Leader --[CommitNotification(commit_index)]--> all Followers (fire-and-forget)
Followers apply committed entries to their local KV stores
raft_kv/
gleam.toml
config.toml -- default config: num_nodes=5, num_clients=3
src/
raft_kv.gleam -- main: read TOML config, start nodes, election, clients
raft_kv/
types.gleam -- Command, OpResult, LogEntry (shared types)
node.gleam -- Raft node actor (all roles)
client.gleam -- client (adapted from multipaxos_kv/client.gleam)
test/
raft_kv_test.gleam -- basic test
types.gleam - Shared typesCommand = Put/Get/Delete/Noop (same as multipaxos_kv/types.gleam)OpResult = OpOk | OpError (same as multipaxos_kv/types.gleam)LogEntry(term: Int, command: Command) - new for Raftnode.gleam - Raft node actor (most complex file)State:
- id, current_term, voted_for: Option(Int), role: Role
- log: Dict(Int, LogEntry) - 1-indexed
- commit_index, last_applied
- peers: List(#(Int, Subject(Message))) - set after startup via SetPeers
- store: Dict(String, String) - KV state machine
- Leader-only: next_index: Dict(Int, Int), match_index: Dict(Int, Int)
Messages:
- SetPeers(List(#(Int, Subject(Message)))) - configuration after startup
- StartElection - trigger election (sent to node 1 by main)
- RequestVote(term, candidate_id, last_log_index, last_log_term, reply_with) / VoteResponse
- AppendEntries(term, leader_id, prev_log_index, prev_log_term, entries, leader_commit, reply_with) / AppendEntriesResponse
- CommitNotification(leader_commit: Int) - fire-and-forget commit update
- ClientPut/ClientGet/ClientDelete - same signatures as multipaxos_kv/leader.gleam
Key functions:
- handle_start_election: Increment term, vote for self, call RequestVote on all peers, become leader on majority
- handle_request_vote: Standard Raft voting logic (term check, log up-to-date check)
- handle_append_entries: Check term, check prev_log match, append entries, update commit_index, apply
- handle_client_request: (Leader only) Append to log, synchronous AppendEntries to peers, on majority: commit, apply, reply, broadcast CommitNotification
- apply_committed: Apply entries from last_applied+1 to commit_index (same KV semantics as multipaxos_kv)
client.gleam - Adapted from multipaxos_kv/client.gleamnode.put, node.get, node.delete instead of leader.*Subject(node.Message) instead of Subject(leader.Message)raft_kv.gleam - Main entry pointnum_nodes (default 5) and num_clients (default 3)config.tomlnum_nodes = 5
num_clients = 3
gleam_stdlib, gleam_otp, gleam_erlang, tom, argv
Note: tom for TOML parsing. argv to optionally accept config file path as CLI arg.
apply_command logic from multipaxos_kv/leader.gleam:106-156 (KV semantics)apply_committed pattern from multipaxos_kv/replica.gleam:27-83 (sequential log application)multipaxos_kv/client.gleam (nearly identical)multipaxos_kv/multipaxos_kv.gleam (start actors, connect, run)gleam build - compiles without errorsgleam run - shows: nodes starting, election completing, clients issuing requests with Raft replication trace, followers applying committed entriesgleam format - code is formattedIf you need specific details from before exiting plan mode (like exact code snippets, error messages, or content you generated), read the full transcript at: /Users/apanda/.claude/projects/-Users-apanda-code-agent-spec-code/b2f3cfa8-4232-4552-95f3-5eccc20c4847.jsonl
{
"type": "tool_reference",
"tool_name": "Read"
}{
"type": "tool_reference",
"tool_name": "Glob"
}{
"type": "tool_reference",
"tool_name": "Write"
}{
"type": "tool_reference",
"tool_name": "Edit"
}{
"type": "tool_reference",
"tool_name": "Bash"
}{
"type": "tool_reference",
"tool_name": "Agent"
}I'll start by reading the existing multipaxos_kv implementation and the create-emulation skill to understand the patterns.
{
"subagent_type": "Explore",
"prompt": "Read ALL files in the multipaxos_kv directory. I need the complete contents of every .gleam file, gleam.toml, and config.toml. Be very thorough - read every single file. The directory is at /Users/apanda/code/agent-spec-code/multipaxos_kv/. List all files first with glob, then read each one completely."
}{
"file_path": "/Users/apanda/code/agent-spec-code/.claude/skills/create-emulation.md"
} 1→## Metadata
2→name: Creating a distributed system emulation
3→description: This is a recipe for how to build a distributed system emulation in Gleam given a human description.
4→
5→
6→## Overview
7→In this environment we use Gleam for emulation. The goal is to produce a version that can be executed and help explain how the protocol (i.e., the algorithm implemented by the system) runs.
8→
9→Each type of process (or node or server, I tend to use the same word for all of them) is implemented as a Gleam actor. The Gleam OTP skill that accompanies this can help write the code. Do not try to optimize the code, but be sure to use comments to document the logic of each actor, and use print statements to record the execution of each actor.
10→
11→Once code for all types of processes has been written, change the main function to take a configuration file (in TOML) that specifies how many nodes of each type to start and then runs them to produce an execution schedule.
12→
13→Finally, use the appropriate version control system to add a commit for the emulation
14→
15→## Steps to Create an Emulation
16→
17→- Use instructions from the gleam-otop skill to create and code up the emulation.
18→- Change the main function of the newly created emulation so that it can read a configuration file written in TOML (you can read it in gleam using the `tom` package) that specifies the number of each type of process.
19→- Create a new commit using the appropriate version control system.
20→
21→## Writing a new emulation
22→
23→Use instructions from the gleam-otp skill.
24→
25→## Version Control
26→
27→Check if the root directory contains a `.jj` directory. If so, the project is managed using Jujutsu, and the accompanying jujutsu skill to manage things.
28→
29→If on the other hand the root directory contains a `.git` directory (but no `.jj` directory) use git.
30→ 1→# Gleam OTP Development
2→
3→## Metadata
4→name: Gleam OTP Development
5→description: This is a skill to help with developing Gleam OTP applications.
6→
7→## Creating a Gleam project
8→
9→```sh
10→ gleam new --skip-git --skip-github <project name> # Create a project. Project name can only contain alphanumeric characters and `_`
11→ cd <project name> # Change directory into the project
12→ gleam add gleam_otp # Add gleam_otp as a dependency
13→ gleam add gleam_erlang # Add gleam_erlang as a dependency.
14→```
15→
16→## Build Commands
17→
18→```sh
19→gleam build # Compile the project
20→gleam run # Run the project
21→gleam test # Run all tests
22→gleam add <pkg> # Add a dependency
23→gleam format # Format code
24→```
25→
26→## Actor Pattern with gleam_otp
27→
28→### Basic Actor Structure
29→
30→```gleam
31→import gleam/otp/actor
32→import gleam/erlang/process.{type Subject}
33→
34→// 1. Define state type
35→pub type State {
36→ State(value: Int, self: Subject(Message))
37→}
38→
39→// 2. Define message type
40→pub type Message {
41→ Set(value: Int) // Fire-and-forget
42→ Get(reply_with: Subject(Int)) // Request-response
43→}
44→
45→// 3. Implement handler
46→fn handle_message(state: State, message: Message) -> actor.Next(State, Message) {
47→ case message {
48→ Set(value) -> actor.continue(State(..state, value: value))
49→ Get(client) -> {
50→ process.send(client, state.value)
51→ actor.continue(state)
52→ }
53→ }
54→}
55→
56→// 4. Start function
57→pub fn start() -> Result(Subject(Message), actor.StartError) {
58→ actor.new_with_initialiser(1000, fn(self) {
59→ actor.initialised(State(value: 0, self: self))
60→ |> actor.returning(self)
61→ |> Ok
62→ })
63→ |> actor.on_message(handle_message)
64→ |> actor.start
65→ |> result.map(fn(started) { started.data })
66→}
67→```
68→
69→### Key Patterns
70→
71→**Fire-and-forget message:**
72→```gleam
73→pub fn set(subject: Subject(Message), value: Int) -> Nil {
74→ actor.send(subject, Set(value))
75→}
76→```
77→
78→**Request-response (blocking call):**
79→```gleam
80→pub fn get(subject: Subject(Message)) -> Int {
81→ actor.call(subject, 1000, Get) // 1000ms timeout
82→}
83→```
84→
85→**Self-messaging (for periodic tasks):**
86→```gleam
87→// In initialiser or handler:
88→process.send_after(state.self, 100, Sync) // Send Sync message after 100ms
89→```
90→
91→**Capturing self reference:**
92→Use `actor.new_with_initialiser` instead of `actor.new` to get access to the actor's own Subject in the initialiser callback.
93→
94→### Handler Return Values
95→
96→- `actor.continue(new_state)` - Keep running with new state
97→- `actor.stop()` - Stop the actor gracefully
98→
99→### Common Imports
100→
101→```gleam
102→import gleam/otp/actor
103→import gleam/erlang/process.{type Subject}
104→import gleam/result
105→import gleam/list
106→import gleam/int
107→import gleam/io
108→```
109→
110→## Testing
111→
112→Test functions must end with `_test` suffix:
113→
114→```gleam
115→import gleeunit
116→
117→pub fn main() -> Nil {
118→ gleeunit.main()
119→}
120→
121→pub fn my_feature_test() {
122→ assert some_condition == True
123→}
124→```
125→
126→## Common Patterns in This Codebase
127→
128→### Peer-to-peer Synchronization
129→
130→Servers maintain a list of peers and periodically broadcast their state:
131→
132→```gleam
133→Sync -> {
134→ list.each(state.peers, fn(peer) {
135→ process.send(peer, Set(state.value))
136→ })
137→ process.send_after(state.self, 100, Sync)
138→ actor.continue(state)
139→}
140→```
141→
142→### Convergence Check
143→
144→Poll until all actors have the same value:
145→
146→```gleam
147→fn wait_for_convergence(servers: List(Subject(Message))) -> Nil {
148→ let values = list.map(servers, get)
149→ case values {
150→ [first, ..rest] -> {
151→ let all_same = list.all(rest, fn(v) { v == first })
152→ case all_same && first > 0 {
153→ True -> io.println("Converged!")
154→ False -> {
155→ process.sleep(100)
156→ wait_for_convergence(servers)
157→ }
158→ }
159→ }
160→ [] -> Nil
161→ }
162→}
163→```
164→
165→## Gleam Syntax Quick Reference
166→
167→**Pattern matching:**
168→```gleam
169→case value {
170→ Some(x) -> x
171→ None -> 0
172→}
173→```
174→
175→**Record update:**
176→```gleam
177→State(..state, value: new_value)
178→```
179→
180→**Pipe operator:**
181→```gleam
182→value
183→|> transform1
184→|> transform2
185→```
186→
187→**Assert (panics on failure):**
188→```gleam
189→let assert Ok(result) = maybe_fails()
190→```
191→
192→**List operations:**
193→```gleam
194→list.map(items, fn(x) { x + 1 })
195→list.each(items, fn(x) { io.println(x) })
196→list.all(items, fn(x) { x > 0 })
197→list.flat_map(items, fn(x) { [x, x] })
198→```
199→Perfect! I have now read all the files in the multipaxos_kv directory. Let me provide you with a complete summary: ## Complete Contents of multipaxos_kv Directory I have successfully read ALL files from the multipaxos_kv directory. Here's what's included: ### Configuration Files **gleam.toml** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/gleam.toml` - Project name: multipaxos_kv, version 1.0.0 - Dependencies: - gleam_stdlib >= 0.44.0 and < 2.0.0 - gleam_otp >= 1.2.0 and < 2.0.0 - gleam_erlang >= 1.3.0 and < 2.0.0 - argv >= 1.0.2 and < 2.0.0 - Dev dependency: gleeunit >= 1.0.0 and < 2.0.0 **manifest.toml** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/manifest.toml` - Auto-generated manifest tracking exact versions of all packages (argv 1.0.2, gleam_erlang 1.3.0, gleam_otp 1.2.0, gleam_stdlib 0.70.0, gleeunit 1.9.0) **README.md** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/README.md` - Standard project documentation with commands to add the package, example usage, and dev instructions ### Source Files **multipaxos_kv.gleam** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv.gleam` - Main entry point - Parses command-line args for number of clients (default: 3) - Starts 3 acceptors, 2 replicas, 1 leader - Creates and starts N clients to send requests - Waits 3 seconds then exits **types.gleam** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/types.gleam` - Defines core types: - `Ballot(round, leader_id)` - ballot numbers for Paxos - `Command` - Put, Get, Delete, Noop operations - `OpResult` - OpOk or OpError results - Includes `compare_ballots` function for ballot comparison **acceptor.gleam** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/acceptor.gleam` - Acceptor actor implementation (Phase 1 & 2 of Paxos) - Maintains `promised_ballot` and `accepted` dict - Handles Prepare and Accept messages - Returns PrepareResponse (Promise or PrepareRejected) and AcceptResponse (Accepted or AcceptRejected) **leader.gleam** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/leader.gleam` - Leader/proposer actor with local KV store - Runs Phase 1 (prepare) during init to establish leadership - Handles client requests: ClientPut, ClientGet, ClientDelete - Runs Phase 2 (accept) for each client request - Applies commands to local store and broadcasts to replicas - Provides public functions: `put()`, `get()`, `delete()` **replica.gleam** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/replica.gleam` - Replica actor (passive learner) - Maintains log and KV store - Handles Commit messages from leader - Applies committed commands in order to local store - Supports Put, Get, Delete, and Noop operations **client.gleam** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/client.gleam` - Client actor that generates random requests - Sends 5 random requests to leader (get, put, or delete) - Randomly selects from keys: a, b, c, d, e - Values generated as: val_<0-99> - Responds to Start and Continue messages ### Test File **multipaxos_kv_test.gleam** - `/Users/apanda/code/agent-spec-code/multipaxos_kv/test/multipaxos_kv_test.gleam` - Single test: `leader_put_get_test()` - Creates 3 acceptors, 2 replicas, 1 leader - Tests: put, get with existing key, put to existing key (error), delete, get non-existent, delete non-existent (error) Note: There is no config.toml file in this directory.
agentId: a663148104a983064 (for resuming to continue this agent's work if needed) <usage>total_tokens: 31493 tool_uses: 15 duration_ms: 25147</usage>
Now let me read the actual source files from multipaxos_kv to get the exact code patterns.
{
"file_path": "/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv.gleam"
} 1→import argv
2→import gleam/erlang/process
3→import gleam/int
4→import gleam/io
5→import gleam/list
6→import multipaxos_kv/acceptor
7→import multipaxos_kv/client
8→import multipaxos_kv/leader
9→import multipaxos_kv/replica
10→
11→/// Helper to create a list [1, 2, ..., n]
12→fn range_list(n: Int) -> List(Int) {
13→ int.range(1, n + 1, [], fn(acc, i) { [i, ..acc] })
14→ |> list.reverse
15→}
16→
17→pub fn main() -> Nil {
18→ // Parse number of clients from command-line args (default: 3)
19→ let num_clients = case argv.load().arguments {
20→ [n_str, ..] -> {
21→ case int.parse(n_str) {
22→ Ok(n) if n > 0 -> n
23→ _ -> {
24→ io.println("Usage: gleam run -- <num_clients>")
25→ panic as "num_clients must be a positive integer"
26→ }
27→ }
28→ }
29→ [] -> 3
30→ }
31→
32→ // Start 3 acceptors
33→ let acceptors =
34→ range_list(3)
35→ |> list.map(fn(i) {
36→ let assert Ok(a) = acceptor.start(i)
37→ io.println("Started acceptor " <> int.to_string(i))
38→ a
39→ })
40→
41→ // Start 2 replicas
42→ let replicas =
43→ range_list(2)
44→ |> list.map(fn(i) {
45→ let assert Ok(r) = replica.start(i)
46→ io.println("Started replica " <> int.to_string(i))
47→ r
48→ })
49→
50→ // Start the leader (runs Phase 1 during init)
51→ let assert Ok(the_leader) = leader.start(1, acceptors, replicas)
52→ io.println("Started leader")
53→
54→ // Start clients
55→ let clients =
56→ range_list(num_clients)
57→ |> list.map(fn(i) {
58→ let assert Ok(c) = client.start(the_leader)
59→ io.println("Started client " <> int.to_string(i))
60→ c
61→ })
62→
63→ // Tell each client to begin sending requests
64→ list.each(clients, fn(c) { process.send(c, client.Start) })
65→ io.println(
66→ "All " <> int.to_string(num_clients) <> " clients started sending requests",
67→ )
68→
69→ // Wait for clients to finish
70→ process.sleep(3000)
71→ io.println("Done")
72→}
73→{
"file_path": "/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/types.gleam"
} 1→import gleam/int
2→import gleam/order.{type Order}
3→
4→/// A Paxos ballot number, consisting of a round and leader ID.
5→/// Higher round wins; ties broken by leader_id.
6→pub type Ballot {
7→ Ballot(round: Int, leader_id: Int)
8→}
9→
10→/// Compare two ballots. Higher round wins; ties broken by leader_id.
11→pub fn compare_ballots(a: Ballot, b: Ballot) -> Order {
12→ case a.round == b.round {
13→ True -> int.compare(a.leader_id, b.leader_id)
14→ False -> int.compare(a.round, b.round)
15→ }
16→}
17→
18→/// A command to be replicated through Paxos.
19→pub type Command {
20→ Put(key: String, value: String)
21→ Get(key: String)
22→ Delete(key: String)
23→ Noop
24→}
25→
26→/// Result of applying a command to the KV store.
27→pub type OpResult {
28→ OpOk
29→ OpError(reason: String)
30→}
31→{
"file_path": "/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/leader.gleam"
} 1→import gleam/dict.{type Dict}
2→import gleam/erlang/process.{type Subject}
3→import gleam/int
4→import gleam/io
5→import gleam/list
6→import gleam/otp/actor
7→import gleam/result
8→import multipaxos_kv/acceptor
9→import multipaxos_kv/replica
10→import multipaxos_kv/types.{type Ballot, type Command}
11→
12→/// Leader state: proposer + learner + KV state machine
13→pub type State {
14→ State(
15→ id: Int,
16→ ballot: Ballot,
17→ acceptors: List(Subject(acceptor.Message)),
18→ replicas: List(Subject(replica.Message)),
19→ quorum_size: Int,
20→ next_slot: Int,
21→ log: Dict(Int, Command),
22→ store: Dict(String, String),
23→ last_applied: Int,
24→ self: Subject(Message),
25→ )
26→}
27→
28→/// Messages the leader handles
29→pub type Message {
30→ /// Client request to insert a key-value pair
31→ ClientPut(key: String, value: String, reply_with: Subject(types.OpResult))
32→ /// Client request to get a value by key
33→ ClientGet(key: String, reply_with: Subject(Result(String, String)))
34→ /// Client request to delete a key
35→ ClientDelete(key: String, reply_with: Subject(types.OpResult))
36→}
37→
38→/// Run Phase 1 (prepare) against all acceptors. Panics if quorum not reached.
39→fn run_phase1(
40→ ballot: Ballot,
41→ acceptors: List(Subject(acceptor.Message)),
42→ quorum_size: Int,
43→) -> Nil {
44→ io.println(
45→ "[leader] Phase 1: sending Prepare("
46→ <> int.to_string(ballot.round)
47→ <> ","
48→ <> int.to_string(ballot.leader_id)
49→ <> ") to "
50→ <> int.to_string(list.length(acceptors))
51→ <> " acceptors",
52→ )
53→ let promises =
54→ list.filter_map(acceptors, fn(acc) {
55→ let response = actor.call(acc, 1000, acceptor.Prepare(ballot, _))
56→ case response {
57→ acceptor.Promise(_accepted) -> Ok(Nil)
58→ acceptor.PrepareRejected(_) -> Error(Nil)
59→ }
60→ })
61→ let num_promises = list.length(promises)
62→ io.println(
63→ "[leader] Phase 1 complete: "
64→ <> int.to_string(num_promises)
65→ <> " promises received (need "
66→ <> int.to_string(quorum_size)
67→ <> ")",
68→ )
69→ case num_promises >= quorum_size {
70→ True -> Nil
71→ False -> panic as "Failed to get quorum in Phase 1"
72→ }
73→}
74→
75→/// Run Phase 2 (accept) for a single slot. Returns True if quorum accepted.
76→fn run_phase2(
77→ slot: Int,
78→ ballot: Ballot,
79→ command: Command,
80→ acceptors: List(Subject(acceptor.Message)),
81→ quorum_size: Int,
82→) -> Bool {
83→ let accepted_count =
84→ list.filter_map(acceptors, fn(acc) {
85→ let response =
86→ actor.call(acc, 1000, acceptor.Accept(slot, ballot, command, _))
87→ case response {
88→ acceptor.Accepted(_) -> Ok(Nil)
89→ acceptor.AcceptRejected(_, _) -> Error(Nil)
90→ }
91→ })
92→ |> list.length
93→ io.println(
94→ "[leader] Phase 2 for slot "
95→ <> int.to_string(slot)
96→ <> ": "
97→ <> int.to_string(accepted_count)
98→ <> "/"
99→ <> int.to_string(quorum_size)
100→ <> " accepted",
101→ )
102→ accepted_count >= quorum_size
103→}
104→
105→/// Apply a command to the KV store, returning the result and updated store
106→fn apply_command(
107→ command: Command,
108→ store: Dict(String, String),
109→) -> #(Dict(String, String), Command, types.OpResult, Result(String, String)) {
110→ case command {
111→ types.Put(key, value) -> {
112→ case dict.has_key(store, key) {
113→ True -> {
114→ io.println("[leader] PUT \"" <> key <> "\" -> REJECTED (key exists)")
115→ #(
116→ store,
117→ command,
118→ types.OpError("key already exists: " <> key),
119→ Error(""),
120→ )
121→ }
122→ False -> {
123→ io.println(
124→ "[leader] PUT \"" <> key <> "\" = \"" <> value <> "\" -> OK",
125→ )
126→ #(dict.insert(store, key, value), command, types.OpOk, Error(""))
127→ }
128→ }
129→ }
130→ types.Get(key) -> {
131→ case dict.get(store, key) {
132→ Ok(value) -> {
133→ io.println("[leader] GET \"" <> key <> "\" -> \"" <> value <> "\"")
134→ #(store, command, types.OpOk, Ok(value))
135→ }
136→ Error(_) -> {
137→ io.println("[leader] GET \"" <> key <> "\" -> NOT FOUND")
138→ #(store, command, types.OpOk, Error("key not found: " <> key))
139→ }
140→ }
141→ }
142→ types.Delete(key) -> {
143→ case dict.has_key(store, key) {
144→ True -> {
145→ io.println("[leader] DELETE \"" <> key <> "\" -> OK")
146→ #(dict.delete(store, key), command, types.OpOk, Error(""))
147→ }
148→ False -> {
149→ io.println("[leader] DELETE \"" <> key <> "\" -> NOT FOUND")
150→ #(store, command, types.OpError("key not found: " <> key), Error(""))
151→ }
152→ }
153→ }
154→ types.Noop -> #(store, command, types.OpOk, Error(""))
155→ }
156→}
157→
158→/// Broadcast a committed command to all replicas
159→fn broadcast_commit(
160→ replicas: List(Subject(replica.Message)),
161→ slot: Int,
162→ command: Command,
163→) -> Nil {
164→ list.each(replicas, fn(r) { process.send(r, replica.Commit(slot, command)) })
165→}
166→
167→/// Handle a client request: assign slot, run Phase 2, apply, reply, broadcast
168→fn handle_client_request(
169→ state: State,
170→ command: Command,
171→ reply_put: fn(types.OpResult) -> Nil,
172→ reply_get: fn(Result(String, String)) -> Nil,
173→) -> actor.Next(State, Message) {
174→ let slot = state.next_slot
175→ io.println(
176→ "[leader] Assigning slot " <> int.to_string(slot) <> " for client request",
177→ )
178→
179→ // Run Phase 2 for this slot
180→ let committed =
181→ run_phase2(slot, state.ballot, command, state.acceptors, state.quorum_size)
182→
183→ case committed {
184→ True -> {
185→ // Apply to local KV store
186→ let #(new_store, cmd, op_result, get_result) =
187→ apply_command(command, state.store)
188→ let new_log = dict.insert(state.log, slot, cmd)
189→
190→ // Reply to client
191→ reply_put(op_result)
192→ reply_get(get_result)
193→
194→ // Broadcast commit to replicas
195→ broadcast_commit(state.replicas, slot, cmd)
196→
197→ actor.continue(
198→ State(
199→ ..state,
200→ next_slot: slot + 1,
201→ log: new_log,
202→ store: new_store,
203→ last_applied: slot,
204→ ),
205→ )
206→ }
207→ False -> {
208→ io.println("[leader] Phase 2 FAILED for slot " <> int.to_string(slot))
209→ reply_put(types.OpError("consensus failed"))
210→ reply_get(Error("consensus failed"))
211→ actor.continue(state)
212→ }
213→ }
214→}
215→
216→/// Handle incoming messages
217→fn handle_message(state: State, message: Message) -> actor.Next(State, Message) {
218→ case message {
219→ ClientPut(key, value, reply_with) -> {
220→ handle_client_request(
221→ state,
222→ types.Put(key, value),
223→ fn(r) { process.send(reply_with, r) },
224→ fn(_) { Nil },
225→ )
226→ }
227→ ClientGet(key, reply_with) -> {
228→ handle_client_request(state, types.Get(key), fn(_) { Nil }, fn(r) {
229→ process.send(reply_with, r)
230→ })
231→ }
232→ ClientDelete(key, reply_with) -> {
233→ handle_client_request(
234→ state,
235→ types.Delete(key),
236→ fn(r) { process.send(reply_with, r) },
237→ fn(_) { Nil },
238→ )
239→ }
240→ }
241→}
242→
243→/// Start a leader actor. Runs Phase 1 during initialization.
244→pub fn start(
245→ id: Int,
246→ acceptors: List(Subject(acceptor.Message)),
247→ replicas: List(Subject(replica.Message)),
248→) -> Result(Subject(Message), actor.StartError) {
249→ let ballot = types.Ballot(round: 1, leader_id: id)
250→ let quorum_size = list.length(acceptors) / 2 + 1
251→
252→ actor.new_with_initialiser(5000, fn(self) {
253→ io.println("[leader] Starting with id " <> int.to_string(id))
254→
255→ // Run Phase 1 to establish leadership
256→ run_phase1(ballot, acceptors, quorum_size)
257→ io.println("[leader] Phase 1 complete — leader established")
258→
259→ let state =
260→ State(
261→ id: id,
262→ ballot: ballot,
263→ acceptors: acceptors,
264→ replicas: replicas,
265→ quorum_size: quorum_size,
266→ next_slot: 1,
267→ log: dict.new(),
268→ store: dict.new(),
269→ last_applied: 0,
270→ self: self,
271→ )
272→ actor.initialised(state)
273→ |> actor.returning(self)
274→ |> Ok
275→ })
276→ |> actor.on_message(handle_message)
277→ |> actor.start
278→ |> result.map(fn(started) { started.data })
279→}
280→
281→/// Put a key-value pair. Returns error if the key already exists.
282→pub fn put(
283→ leader: Subject(Message),
284→ key: String,
285→ value: String,
286→) -> types.OpResult {
287→ actor.call(leader, 5000, ClientPut(key, value, _))
288→}
289→
290→/// Get the value for a key. Returns Error if not found.
291→pub fn get(leader: Subject(Message), key: String) -> Result(String, String) {
292→ actor.call(leader, 5000, ClientGet(key, _))
293→}
294→
295→/// Delete a key. Returns error if the key doesn't exist.
296→pub fn delete(leader: Subject(Message), key: String) -> types.OpResult {
297→ actor.call(leader, 5000, ClientDelete(key, _))
298→}
299→{
"file_path": "/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/client.gleam"
} 1→import gleam/erlang/process.{type Subject}
2→import gleam/int
3→import gleam/io
4→import gleam/otp/actor
5→import gleam/result
6→import multipaxos_kv/leader
7→import multipaxos_kv/types
8→
9→/// Client state
10→pub type State {
11→ State(leader: Subject(leader.Message), remaining: Int, self: Subject(Message))
12→}
13→
14→/// Messages the client responds to
15→pub type Message {
16→ /// Kick off the client's request loop
17→ Start
18→ /// Internal message to continue sending the next request
19→ Continue
20→}
21→
22→/// A small pool of keys the client randomly picks from
23→const keys = #("a", "b", "c", "d", "e")
24→
25→/// Pick a random key from the pool
26→fn random_key() -> String {
27→ case int.random(5) {
28→ 0 -> keys.0
29→ 1 -> keys.1
30→ 2 -> keys.2
31→ 3 -> keys.3
32→ _ -> keys.4
33→ }
34→}
35→
36→/// Pick a random value
37→fn random_value() -> String {
38→ "val_" <> int.to_string(int.random(100))
39→}
40→
41→/// Handle incoming messages
42→fn handle_message(state: State, message: Message) -> actor.Next(State, Message) {
43→ case message {
44→ Start -> {
45→ io.println("[client] Starting — will send 5 requests")
46→ send_next_request(state)
47→ }
48→ Continue -> {
49→ send_next_request(state)
50→ }
51→ }
52→}
53→
54→/// Send the next random request to the leader via Paxos
55→fn send_next_request(state: State) -> actor.Next(State, Message) {
56→ case state.remaining {
57→ 0 -> {
58→ io.println("[client] Finished all 5 requests")
59→ actor.stop()
60→ }
61→ n -> {
62→ // Randomly choose between get (0), put (1), and delete (2)
63→ case int.random(3) {
64→ 0 -> {
65→ let key = random_key()
66→ case leader.get(state.leader, key) {
67→ Ok(value) ->
68→ io.println(
69→ "[client] GET \"" <> key <> "\" -> \"" <> value <> "\"",
70→ )
71→ Error(reason) ->
72→ io.println("[client] GET \"" <> key <> "\" -> " <> reason)
73→ }
74→ }
75→ 1 -> {
76→ let key = random_key()
77→ let value = random_value()
78→ case leader.put(state.leader, key, value) {
79→ types.OpOk ->
80→ io.println(
81→ "[client] PUT \"" <> key <> "\" = \"" <> value <> "\" -> OK",
82→ )
83→ types.OpError(reason) ->
84→ io.println(
85→ "[client] PUT \""
86→ <> key
87→ <> "\" = \""
88→ <> value
89→ <> "\" -> "
90→ <> reason,
91→ )
92→ }
93→ }
94→ _ -> {
95→ let key = random_key()
96→ case leader.delete(state.leader, key) {
97→ types.OpOk -> io.println("[client] DELETE \"" <> key <> "\" -> OK")
98→ types.OpError(reason) ->
99→ io.println("[client] DELETE \"" <> key <> "\" -> " <> reason)
100→ }
101→ }
102→ }
103→
104→ // Schedule next request
105→ process.send(state.self, Continue)
106→ actor.continue(State(..state, remaining: n - 1))
107→ }
108→ }
109→}
110→
111→/// Start a client actor that will send 5 random requests to the leader
112→pub fn start(
113→ leader_subject: Subject(leader.Message),
114→) -> Result(Subject(Message), actor.StartError) {
115→ actor.new_with_initialiser(1000, fn(self) {
116→ let state = State(leader: leader_subject, remaining: 5, self: self)
117→ actor.initialised(state)
118→ |> actor.returning(self)
119→ |> Ok
120→ })
121→ |> actor.on_message(handle_message)
122→ |> actor.start
123→ |> result.map(fn(started) { started.data })
124→}
125→{
"file_path": "/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/replica.gleam"
} 1→import gleam/dict.{type Dict}
2→import gleam/erlang/process.{type Subject}
3→import gleam/int
4→import gleam/io
5→import gleam/otp/actor
6→import gleam/result
7→import multipaxos_kv/types.{type Command}
8→
9→/// Replica state: passive learner that applies committed commands
10→pub type State {
11→ State(
12→ id: Int,
13→ log: Dict(Int, Command),
14→ store: Dict(String, String),
15→ last_applied: Int,
16→ self: Subject(Message),
17→ )
18→}
19→
20→/// Messages the replica handles
21→pub type Message {
22→ /// A committed command from the leader
23→ Commit(slot: Int, command: Command)
24→}
25→
26→/// Apply commands from the log in order, starting from last_applied + 1
27→fn apply_committed(state: State) -> State {
28→ let next_slot = state.last_applied + 1
29→ case dict.get(state.log, next_slot) {
30→ Error(_) -> state
31→ Ok(command) -> {
32→ let id_str = int.to_string(state.id)
33→ let slot_str = int.to_string(next_slot)
34→ let new_store = case command {
35→ types.Put(key, value) -> {
36→ io.println(
37→ "[replica "
38→ <> id_str
39→ <> "] slot "
40→ <> slot_str
41→ <> ": PUT \""
42→ <> key
43→ <> "\" = \""
44→ <> value
45→ <> "\"",
46→ )
47→ dict.insert(state.store, key, value)
48→ }
49→ types.Get(key) -> {
50→ io.println(
51→ "[replica "
52→ <> id_str
53→ <> "] slot "
54→ <> slot_str
55→ <> ": GET \""
56→ <> key
57→ <> "\"",
58→ )
59→ state.store
60→ }
61→ types.Delete(key) -> {
62→ io.println(
63→ "[replica "
64→ <> id_str
65→ <> "] slot "
66→ <> slot_str
67→ <> ": DELETE \""
68→ <> key
69→ <> "\"",
70→ )
71→ dict.delete(state.store, key)
72→ }
73→ types.Noop -> {
74→ io.println("[replica " <> id_str <> "] slot " <> slot_str <> ": NOOP")
75→ state.store
76→ }
77→ }
78→ let new_state = State(..state, store: new_store, last_applied: next_slot)
79→ // Try to apply the next slot too (in case commits arrived out of order)
80→ apply_committed(new_state)
81→ }
82→ }
83→}
84→
85→/// Handle incoming messages
86→fn handle_message(state: State, message: Message) -> actor.Next(State, Message) {
87→ case message {
88→ Commit(slot, command) -> {
89→ let new_log = dict.insert(state.log, slot, command)
90→ let new_state = apply_committed(State(..state, log: new_log))
91→ actor.continue(new_state)
92→ }
93→ }
94→}
95→
96→/// Start a replica actor with the given ID
97→pub fn start(id: Int) -> Result(Subject(Message), actor.StartError) {
98→ actor.new_with_initialiser(1000, fn(self) {
99→ io.println("[replica " <> int.to_string(id) <> "] Starting")
100→ let state =
101→ State(
102→ id: id,
103→ log: dict.new(),
104→ store: dict.new(),
105→ last_applied: 0,
106→ self: self,
107→ )
108→ actor.initialised(state)
109→ |> actor.returning(self)
110→ |> Ok
111→ })
112→ |> actor.on_message(handle_message)
113→ |> actor.start
114→ |> result.map(fn(started) { started.data })
115→}
116→{
"file_path": "/Users/apanda/code/agent-spec-code/multipaxos_kv/src/multipaxos_kv/acceptor.gleam"
} 1→import gleam/dict.{type Dict}
2→import gleam/erlang/process.{type Subject}
3→import gleam/int
4→import gleam/io
5→import gleam/order
6→import gleam/otp/actor
7→import gleam/result
8→import multipaxos_kv/types.{type Ballot, type Command}
9→
10→/// Acceptor state
11→pub type State {
12→ State(
13→ id: Int,
14→ promised_ballot: Ballot,
15→ accepted: Dict(Int, #(Ballot, Command)),
16→ self: Subject(Message),
17→ )
18→}
19→
20→/// Response to a Prepare request
21→pub type PrepareResponse {
22→ /// Promise not to accept lower ballots; includes previously accepted entries
23→ Promise(accepted: Dict(Int, #(Ballot, Command)))
24→ /// Rejected because a higher ballot was already promised
25→ PrepareRejected(highest: Ballot)
26→}
27→
28→/// Response to an Accept request
29→pub type AcceptResponse {
30→ /// Successfully accepted the value for this slot
31→ Accepted(slot: Int)
32→ /// Rejected because a higher ballot was already promised
33→ AcceptRejected(slot: Int, highest: Ballot)
34→}
35→
36→/// Messages the acceptor handles
37→pub type Message {
38→ /// Phase 1: Prepare request from a proposer
39→ Prepare(ballot: Ballot, reply_with: Subject(PrepareResponse))
40→ /// Phase 2: Accept request from a proposer
41→ Accept(
42→ slot: Int,
43→ ballot: Ballot,
44→ command: Command,
45→ reply_with: Subject(AcceptResponse),
46→ )
47→}
48→
49→/// Handle incoming messages
50→fn handle_message(state: State, message: Message) -> actor.Next(State, Message) {
51→ let id_str = int.to_string(state.id)
52→ case message {
53→ Prepare(ballot, reply_with) -> {
54→ // Accept if ballot >= promised_ballot
55→ case types.compare_ballots(ballot, state.promised_ballot) {
56→ order.Lt -> {
57→ io.println(
58→ "[acceptor "
59→ <> id_str
60→ <> "] PREPARE rejected (higher ballot promised)",
61→ )
62→ process.send(reply_with, PrepareRejected(state.promised_ballot))
63→ actor.continue(state)
64→ }
65→ _ -> {
66→ io.println(
67→ "[acceptor "
68→ <> id_str
69→ <> "] PREPARE accepted, promising ballot ("
70→ <> int.to_string(ballot.round)
71→ <> ","
72→ <> int.to_string(ballot.leader_id)
73→ <> ")",
74→ )
75→ process.send(reply_with, Promise(state.accepted))
76→ actor.continue(State(..state, promised_ballot: ballot))
77→ }
78→ }
79→ }
80→
81→ Accept(slot, ballot, command, reply_with) -> {
82→ // Accept if ballot >= promised_ballot
83→ case types.compare_ballots(ballot, state.promised_ballot) {
84→ order.Lt -> {
85→ io.println(
86→ "[acceptor "
87→ <> id_str
88→ <> "] ACCEPT rejected for slot "
89→ <> int.to_string(slot),
90→ )
91→ process.send(reply_with, AcceptRejected(slot, state.promised_ballot))
92→ actor.continue(state)
93→ }
94→ _ -> {
95→ io.println(
96→ "[acceptor "
97→ <> id_str
98→ <> "] ACCEPT for slot "
99→ <> int.to_string(slot)
100→ <> " -> accepted",
101→ )
102→ let new_accepted =
103→ dict.insert(state.accepted, slot, #(ballot, command))
104→ process.send(reply_with, Accepted(slot))
105→ actor.continue(
106→ State(..state, promised_ballot: ballot, accepted: new_accepted),
107→ )
108→ }
109→ }
110→ }
111→ }
112→}
113→
114→/// Start an acceptor actor with the given ID
115→pub fn start(id: Int) -> Result(Subject(Message), actor.StartError) {
116→ actor.new_with_initialiser(1000, fn(self) {
117→ io.println("[acceptor " <> int.to_string(id) <> "] Starting")
118→ let state =
119→ State(
120→ id: id,
121→ promised_ballot: types.Ballot(round: 0, leader_id: 0),
122→ accepted: dict.new(),
123→ self: self,
124→ )
125→ actor.initialised(state)
126→ |> actor.returning(self)
127→ |> Ok
128→ })
129→ |> actor.on_message(handle_message)
130→ |> actor.start
131→ |> result.map(fn(started) { started.data })
132→}
133→{
"file_path": "/Users/apanda/code/agent-spec-code/multipaxos_kv/test/multipaxos_kv_test.gleam"
} 1→import gleeunit
2→import multipaxos_kv/acceptor
3→import multipaxos_kv/leader
4→import multipaxos_kv/replica
5→import multipaxos_kv/types
6→
7→pub fn main() -> Nil {
8→ gleeunit.main()
9→}
10→
11→pub fn leader_put_get_test() {
12→ let assert Ok(a1) = acceptor.start(1)
13→ let assert Ok(a2) = acceptor.start(2)
14→ let assert Ok(a3) = acceptor.start(3)
15→ let assert Ok(r1) = replica.start(1)
16→ let assert Ok(l) = leader.start(1, [a1, a2, a3], [r1])
17→
18→ let assert types.OpOk = leader.put(l, "x", "hello")
19→ let assert Ok("hello") = leader.get(l, "x")
20→ let assert types.OpError(_) = leader.put(l, "x", "world")
21→ let assert types.OpOk = leader.delete(l, "x")
22→ let assert Error(_) = leader.get(l, "x")
23→ let assert types.OpError(_) = leader.delete(l, "x")
24→}
25→ 1→name = "multipaxos_kv"
2→version = "1.0.0"
3→
4→# Fill out these fields if you intend to generate HTML documentation or publish
5→# your project to the Hex package manager.
6→#
7→# description = ""
8→# licences = ["Apache-2.0"]
9→# repository = { type = "github", user = "", repo = "" }
10→# links = [{ title = "Website", href = "" }]
11→#
12→# For a full reference of all the available options, you can have a look at
13→# https://gleam.run/writing-gleam/gleam-toml/.
14→
15→[dependencies]
16→gleam_stdlib = ">= 0.44.0 and < 2.0.0"
17→gleam_otp = ">= 1.2.0 and < 2.0.0"
18→gleam_erlang = ">= 1.3.0 and < 2.0.0"
19→argv = ">= 1.0.2 and < 2.0.0"
20→
21→[dev-dependencies]
22→gleeunit = ">= 1.0.0 and < 2.0.0"
23→Now I have a thorough understanding of the patterns. Let me check if any other emulation uses TOML config to see the pattern.
No existing TOML config pattern. Let me now create the raft_kv project. First, create the project scaffolding.
gleam new --skip-git --skip-github raft_kv && cd raft_kv && gleam add gleam_otp && gleam add gleam_erlang && gleam add tom && gleam add argv
Your Gleam project raft_kv has been successfully created.
The project can be compiled and tested by running these commands:
cd raft_kv
gleam test
Resolving versions
Downloading packages
Downloaded 4 packages in 0.04s
Added gleam_erlang v1.3.0
Added gleam_otp v1.2.0
Added gleam_stdlib v0.70.0
Added gleeunit v1.9.0
Resolving versions
Resolving versions
Downloading packages
Downloaded 2 packages in 0.03s
Added gleam_time v1.7.0
Added tom v2.0.1
Resolving versions
Downloading packages
Downloaded 1 package in 0.01s
Added argv v1.0.2num_nodes = 5 num_clients = 3
/// A command to be replicated through Raft.
pub type Command {
Put(key: String, value: String)
Get(key: String)
Delete(key: String)
Noop
}
/// Result of applying a command to the KV store.
pub type OpResult {
OpOk
OpError(reason: String)
}
/// A single entry in the Raft log, tagged with the term it was created in.
pub type LogEntry {
LogEntry(term: Int, command: Command)
}
File created successfully at: /Users/apanda/code/agent-spec-code/raft_kv/src/raft_kv/types.gleam
import gleam/dict.{type Dict}
import gleam/erlang/process.{type Subject}
import gleam/int
import gleam/io
import gleam/list
import gleam/option.{type Option, None, Some}
import gleam/otp/actor
import gleam/result
import raft_kv/types.{type Command, type LogEntry}
/// Role a Raft node can be in
pub type Role {
Follower
Candidate
Leader
}
/// Raft node state
pub type State {
State(
id: Int,
current_term: Int,
voted_for: Option(Int),
role: Role,
// Log is 1-indexed: index -> LogEntry
log: Dict(Int, LogEntry),
commit_index: Int,
last_applied: Int,
// Peer nodes (id, subject) — does not include self
peers: List(#(Int, Subject(Message))),
// KV state machine
store: Dict(String, String),
// Leader-only state
next_index: Dict(Int, Int),
match_index: Dict(Int, Int),
// Total number of nodes in the cluster (including self)
cluster_size: Int,
self: Subject(Message),
)
}
/// Response to a RequestVote RPC
pub type VoteResponse {
VoteGranted(term: Int)
VoteDenied(term: Int)
}
/// Response to an AppendEntries RPC
pub type AppendEntriesResponse {
AppendEntriesOk(term: Int, match_index: Int)
AppendEntriesRejected(term: Int)
}
/// Messages the Raft node handles
pub type Message {
/// Configuration: set peer nodes after all are started
SetPeers(peers: List(#(Int, Subject(Message))))
/// Trigger an election (sent to a designated node by main)
StartElection
/// RequestVote RPC from a candidate
RequestVote(
term: Int,
candidate_id: Int,
last_log_index: Int,
last_log_term: Int,
reply_with: Subject(VoteResponse),
)
/// AppendEntries RPC from the leader
AppendEntries(
term: Int,
leader_id: Int,
prev_log_index: Int,
prev_log_term: Int,
entries: List(#(Int, LogEntry)),
leader_commit: Int,
reply_with: Subject(AppendEntriesResponse),
)
/// Fire-and-forget notification that the leader's commit index advanced
CommitNotification(leader_commit: Int)
/// Client request to insert a key-value pair
ClientPut(key: String, value: String, reply_with: Subject(types.OpResult))
/// Client request to get a value by key
ClientGet(key: String, reply_with: Subject(Result(String, String)))
/// Client request to delete a key
ClientDelete(key: String, reply_with: Subject(types.OpResult))
}
/// Get the last log index (0 if log is empty)
fn last_log_index(log: Dict(Int, LogEntry)) -> Int {
dict.keys(log)
|> list.fold(0, int.max)
}
/// Get the term of a log entry at a given index (0 if not present)
fn log_term_at(log: Dict(Int, LogEntry), index: Int) -> Int {
case dict.get(log, index) {
Ok(entry) -> entry.term
Error(_) -> 0
}
}
/// Compute quorum size for a cluster
fn quorum_size(cluster_size: Int) -> Int {
cluster_size / 2 + 1
}
/// Handle the StartElection message: run a Raft leader election
fn handle_start_election(state: State) -> actor.Next(State, Message) {
let new_term = state.current_term + 1
let id_str = int.to_string(state.id)
io.println(
"[node "
<> id_str
<> "] Starting election for term "
<> int.to_string(new_term),
)
let my_last_index = last_log_index(state.log)
let my_last_term = log_term_at(state.log, my_last_index)
// Vote for self
let votes_needed = quorum_size(state.cluster_size)
// Count self vote = 1, then call peers for votes
let peer_votes =
list.filter_map(state.peers, fn(peer) {
let #(peer_id, peer_subject) = peer
let response =
actor.call(peer_subject, 1000, RequestVote(
new_term,
state.id,
my_last_index,
my_last_term,
_,
))
case response {
VoteGranted(_) -> {
io.println(
"[node "
<> id_str
<> "] Received vote from node "
<> int.to_string(peer_id),
)
Ok(Nil)
}
VoteDenied(_) -> Error(Nil)
}
})
let total_votes = 1 + list.length(peer_votes)
io.println(
"[node "
<> id_str
<> "] Election result: "
<> int.to_string(total_votes)
<> " votes (need "
<> int.to_string(votes_needed)
<> ")",
)
case total_votes >= votes_needed {
True -> {
io.println("[node " <> id_str <> "] Became LEADER for term " <> int.to_string(new_term))
// Initialize next_index and match_index for each peer
let next_idx = last_log_index(state.log) + 1
let new_next_index =
list.fold(state.peers, dict.new(), fn(acc, peer) {
dict.insert(acc, peer.0, next_idx)
})
let new_match_index =
list.fold(state.peers, dict.new(), fn(acc, peer) {
dict.insert(acc, peer.0, 0)
})
actor.continue(State(
..state,
current_term: new_term,
voted_for: Some(state.id),
role: Leader,
next_index: new_next_index,
match_index: new_match_index,
))
}
False -> {
io.println("[node " <> id_str <> "] Election FAILED, staying follower")
actor.continue(State(
..state,
current_term: new_term,
voted_for: Some(state.id),
role: Follower,
))
}
}
}
/// Handle a RequestVote RPC
fn handle_request_vote(
state: State,
term: Int,
candidate_id: Int,
candidate_last_index: Int,
candidate_last_term: Int,
reply_with: Subject(VoteResponse),
) -> actor.Next(State, Message) {
let id_str = int.to_string(state.id)
// If candidate's term is less than ours, deny
case term < state.current_term {
True -> {
io.println(
"[node "
<> id_str
<> "] Denying vote to "
<> int.to_string(candidate_id)
<> " (stale term)",
)
process.send(reply_with, VoteDenied(state.current_term))
actor.continue(state)
}
False -> {
// Step down if term is higher
let updated_state = case term > state.current_term {
True ->
State(
..state,
current_term: term,
voted_for: None,
role: Follower,
)
False -> state
}
// Check if we can grant the vote
let can_vote = case updated_state.voted_for {
None -> True
Some(id) -> id == candidate_id
}
// Check log up-to-date: candidate's log must be at least as up-to-date
let my_last_index = last_log_index(updated_state.log)
let my_last_term = log_term_at(updated_state.log, my_last_index)
let log_ok =
candidate_last_term > my_last_term
|| { candidate_last_term == my_last_term && candidate_last_index >= my_last_index }
case can_vote && log_ok {
True -> {
io.println(
"[node "
<> id_str
<> "] Granting vote to "
<> int.to_string(candidate_id)
<> " for term "
<> int.to_string(term),
)
process.send(reply_with, VoteGranted(term))
actor.continue(State(
..updated_state,
voted_for: Some(candidate_id),
))
}
False -> {
io.println(
"[node "
<> id_str
<> "] Denying vote to "
<> int.to_string(candidate_id),
)
process.send(reply_with, VoteDenied(updated_state.current_term))
actor.continue(updated_state)
}
}
}
}
}
/// Handle an AppendEntries RPC (from leader)
fn handle_append_entries(
state: State,
term: Int,
leader_id: Int,
prev_log_index: Int,
prev_log_term: Int,
entries: List(#(Int, LogEntry)),
leader_commit: Int,
reply_with: Subject(AppendEntriesResponse),
) -> actor.Next(State, Message) {
let id_str = int.to_string(state.id)
// Reject if term < current_term
case term < state.current_term {
True -> {
io.println(
"[node "
<> id_str
<> "] Rejecting AppendEntries from node "
<> int.to_string(leader_id)
<> " (stale term)",
)
process.send(reply_with, AppendEntriesRejected(state.current_term))
actor.continue(state)
}
False -> {
// Step down / update term if needed
let updated_state =
State(..state, current_term: term, role: Follower, voted_for: case
term > state.current_term
{
True -> None
False -> state.voted_for
})
// Check prev_log consistency
let prev_ok = case prev_log_index {
0 -> True
_ -> log_term_at(updated_state.log, prev_log_index) == prev_log_term
}
case prev_ok {
False -> {
io.println(
"[node "
<> id_str
<> "] AppendEntries log mismatch at index "
<> int.to_string(prev_log_index),
)
process.send(
reply_with,
AppendEntriesRejected(updated_state.current_term),
)
actor.continue(updated_state)
}
True -> {
// Append entries to log
let new_log =
list.fold(entries, updated_state.log, fn(log, entry) {
let #(index, log_entry) = entry
dict.insert(log, index, log_entry)
})
// Update commit_index
let new_commit_index = case leader_commit > updated_state.commit_index {
True -> {
let last_new_index = case list.last(entries) {
Ok(#(idx, _)) -> idx
Error(_) -> updated_state.commit_index
}
int.min(leader_commit, last_new_index)
}
False -> updated_state.commit_index
}
let match_idx = last_log_index(new_log)
io.println(
"[node "
<> id_str
<> "] AppendEntries OK from leader "
<> int.to_string(leader_id)
<> ", match_index="
<> int.to_string(match_idx),
)
process.send(
reply_with,
AppendEntriesOk(updated_state.current_term, match_idx),
)
// Apply newly committed entries
let final_state =
apply_committed(State(
..updated_state,
log: new_log,
commit_index: new_commit_index,
))
actor.continue(final_state)
}
}
}
}
}
/// Handle a CommitNotification from the leader
fn handle_commit_notification(
state: State,
leader_commit: Int,
) -> actor.Next(State, Message) {
let id_str = int.to_string(state.id)
let new_commit_index = case leader_commit > state.commit_index {
True -> leader_commit
False -> state.commit_index
}
io.println(
"[node "
<> id_str
<> "] CommitNotification: commit_index updated to "
<> int.to_string(new_commit_index),
)
let new_state =
apply_committed(State(..state, commit_index: new_commit_index))
actor.continue(new_state)
}
/// Apply committed log entries to the KV state machine
fn apply_committed(state: State) -> State {
let next = state.last_applied + 1
case next > state.commit_index {
True -> state
False -> {
case dict.get(state.log, next) {
Error(_) -> state
Ok(entry) -> {
let id_str = int.to_string(state.id)
let slot_str = int.to_string(next)
let new_store = case entry.command {
types.Put(key, value) -> {
case dict.has_key(state.store, key) {
True -> {
io.println(
"[node "
<> id_str
<> "] slot "
<> slot_str
<> ": PUT \""
<> key
<> "\" -> REJECTED (key exists)",
)
state.store
}
False -> {
io.println(
"[node "
<> id_str
<> "] slot "
<> slot_str
<> ": PUT \""
<> key
<> "\" = \""
<> value
<> "\" -> OK",
)
dict.insert(state.store, key, value)
}
}
}
types.Get(key) -> {
case dict.get(state.store, key) {
Ok(value) ->
io.println(
"[node "
<> id_str
<> "] slot "
<> slot_str
<> ": GET \""
<> key
<> "\" -> \""
<> value
<> "\"",
)
Error(_) ->
io.println(
"[node "
<> id_str
<> "] slot "
<> slot_str
<> ": GET \""
<> key
<> "\" -> NOT FOUND",
)
}
state.store
}
types.Delete(key) -> {
case dict.has_key(state.store, key) {
True -> {
io.println(
"[node "
<> id_str
<> "] slot "
<> slot_str
<> ": DELETE \""
<> key
<> "\" -> OK",
)
dict.delete(state.store, key)
}
False -> {
io.println(
"[node "
<> id_str
<> "] slot "
<> slot_str
<> ": DELETE \""
<> key
<> "\" -> NOT FOUND",
)
state.store
}
}
}
types.Noop -> {
io.println(
"[node " <> id_str <> "] slot " <> slot_str <> ": NOOP",
)
state.store
}
}
let new_state =
State(..state, store: new_store, last_applied: next)
// Recursively apply next entry
apply_committed(new_state)
}
}
}
}
}
/// Apply a command to the KV store and return the result (used by leader for client replies)
fn apply_command_result(
command: Command,
store: Dict(String, String),
id_str: String,
) -> #(Dict(String, String), types.OpResult, Result(String, String)) {
case command {
types.Put(key, value) -> {
case dict.has_key(store, key) {
True -> {
io.println(
"[node " <> id_str <> "] PUT \"" <> key <> "\" -> REJECTED (key exists)",
)
#(store, types.OpError("key already exists: " <> key), Error(""))
}
False -> {
io.println(
"[node "
<> id_str
<> "] PUT \""
<> key
<> "\" = \""
<> value
<> "\" -> OK",
)
#(dict.insert(store, key, value), types.OpOk, Error(""))
}
}
}
types.Get(key) -> {
case dict.get(store, key) {
Ok(value) -> {
io.println(
"[node " <> id_str <> "] GET \"" <> key <> "\" -> \"" <> value <> "\"",
)
#(store, types.OpOk, Ok(value))
}
Error(_) -> {
io.println(
"[node " <> id_str <> "] GET \"" <> key <> "\" -> NOT FOUND",
)
#(store, types.OpOk, Error("key not found: " <> key))
}
}
}
types.Delete(key) -> {
case dict.has_key(store, key) {
True -> {
io.println("[node " <> id_str <> "] DELETE \"" <> key <> "\" -> OK")
#(dict.delete(store, key), types.OpOk, Error(""))
}
False -> {
io.println(
"[node " <> id_str <> "] DELETE \"" <> key <> "\" -> NOT FOUND",
)
#(store, types.OpError("key not found: " <> key), Error(""))
}
}
}
types.Noop -> #(store, types.OpOk, Error(""))
}
}
/// Handle a client request (leader only): append to log, replicate, commit, reply
fn handle_client_request(
state: State,
command: Command,
reply_put: fn(types.OpResult) -> Nil,
reply_get: fn(Result(String, String)) -> Nil,
) -> actor.Next(State, Message) {
let id_str = int.to_string(state.id)
// Only the leader handles client requests
case state.role {
Leader -> {
// Append entry to local log
let new_index = last_log_index(state.log) + 1
let entry = types.LogEntry(term: state.current_term, command: command)
let new_log = dict.insert(state.log, new_index, entry)
io.println(
"[node "
<> id_str
<> "] Appending entry at index "
<> int.to_string(new_index)
<> " (term "
<> int.to_string(state.current_term)
<> ")",
)
// Send AppendEntries to all peers (synchronous calls)
let prev_index = new_index - 1
let prev_term = log_term_at(state.log, prev_index)
let entries_to_send = [#(new_index, entry)]
let ack_count =
list.filter_map(state.peers, fn(peer) {
let #(peer_id, peer_subject) = peer
let response =
actor.call(peer_subject, 2000, AppendEntries(
state.current_term,
state.id,
prev_index,
prev_term,
entries_to_send,
state.commit_index,
_,
))
case response {
AppendEntriesOk(_, match_idx) -> {
io.println(
"[node "
<> id_str
<> "] AppendEntries ACK from node "
<> int.to_string(peer_id)
<> " (match="
<> int.to_string(match_idx)
<> ")",
)
Ok(#(peer_id, match_idx))
}
AppendEntriesRejected(_) -> {
io.println(
"[node "
<> id_str
<> "] AppendEntries NACK from node "
<> int.to_string(peer_id),
)
Error(Nil)
}
}
})
// Count: self + successful acks
let total_acks = 1 + list.length(ack_count)
let needed = quorum_size(state.cluster_size)
io.println(
"[node "
<> id_str
<> "] Replication: "
<> int.to_string(total_acks)
<> "/"
<> int.to_string(needed)
<> " acks",
)
case total_acks >= needed {
True -> {
// Commit: advance commit_index and apply
let new_commit_index = new_index
let #(new_store, op_result, get_result) =
apply_command_result(command, state.store, id_str)
// Reply to client
reply_put(op_result)
reply_get(get_result)
// Update match_index for peers that acked
let new_match_index =
list.fold(ack_count, state.match_index, fn(acc, ack) {
let #(peer_id, match_idx) = ack
dict.insert(acc, peer_id, match_idx)
})
// Send CommitNotification to all peers (fire-and-forget)
list.each(state.peers, fn(peer) {
process.send(peer.1, CommitNotification(new_commit_index))
})
actor.continue(State(
..state,
log: new_log,
commit_index: new_commit_index,
last_applied: new_index,
store: new_store,
match_index: new_match_index,
))
}
False -> {
io.println(
"[node "
<> id_str
<> "] Replication FAILED for index "
<> int.to_string(new_index),
)
reply_put(types.OpError("replication failed"))
reply_get(Error("replication failed"))
actor.continue(State(..state, log: new_log))
}
}
}
_ -> {
io.println("[node " <> id_str <> "] Not leader, rejecting client request")
reply_put(types.OpError("not leader"))
reply_get(Error("not leader"))
actor.continue(state)
}
}
}
/// Handle incoming messages
fn handle_message(state: State, message: Message) -> actor.Next(State, Message) {
case message {
SetPeers(peers) -> {
io.println(
"[node "
<> int.to_string(state.id)
<> "] Peers configured ("
<> int.to_string(list.length(peers))
<> " peers)",
)
actor.continue(State(..state, peers: peers))
}
StartElection -> handle_start_election(state)
RequestVote(term, candidate_id, last_idx, last_term, reply_with) ->
handle_request_vote(
state,
term,
candidate_id,
last_idx,
last_term,
reply_with,
)
AppendEntries(
term,
leader_id,
prev_index,
prev_term,
entries,
leader_commit,
reply_with,
) ->
handle_append_entries(
state,
term,
leader_id,
prev_index,
prev_term,
entries,
leader_commit,
reply_with,
)
CommitNotification(leader_commit) ->
handle_commit_notification(state, leader_commit)
ClientPut(key, value, reply_with) ->
handle_client_request(
state,
types.Put(key, value),
fn(r) { process.send(reply_with, r) },
fn(_) { Nil },
)
ClientGet(key, reply_with) ->
handle_client_request(state, types.Get(key), fn(_) { Nil }, fn(r) {
process.send(reply_with, r)
})
ClientDelete(key, reply_with) ->
handle_client_request(
state,
types.Delete(key),
fn(r) { process.send(reply_with, r) },
fn(_) { Nil },
)
}
}
/// Start a Raft node actor with the given ID and cluster size
pub fn start(
id: Int,
cluster_size: Int,
) -> Result(Subject(Message), actor.StartError) {
actor.new_with_initialiser(1000, fn(self) {
io.println("[node " <> int.to_string(id) <> "] Starting")
let state =
State(
id: id,
current_term: 0,
voted_for: None,
role: Follower,
log: dict.new(),
commit_index: 0,
last_applied: 0,
peers: [],
store: dict.new(),
next_index: dict.new(),
match_index: dict.new(),
cluster_size: cluster_size,
self: self,
)
actor.initialised(state)
|> actor.returning(self)
|> Ok
})
|> actor.on_message(handle_message)
|> actor.start
|> result.map(fn(started) { started.data })
}
/// Put a key-value pair. Returns error if the key already exists.
pub fn put(
node: Subject(Message),
key: String,
value: String,
) -> types.OpResult {
actor.call(node, 5000, ClientPut(key, value, _))
}
/// Get the value for a key. Returns Error if not found.
pub fn get(node: Subject(Message), key: String) -> Result(String, String) {
actor.call(node, 5000, ClientGet(key, _))
}
/// Delete a key. Returns error if the key doesn't exist.
pub fn delete(node: Subject(Message), key: String) -> types.OpResult {
actor.call(node, 5000, ClientDelete(key, _))
}
File created successfully at: /Users/apanda/code/agent-spec-code/raft_kv/src/raft_kv/node.gleam
import gleam/erlang/process.{type Subject}
import gleam/int
import gleam/io
import gleam/otp/actor
import gleam/result
import raft_kv/node
import raft_kv/types
/// Client state
pub type State {
State(leader: Subject(node.Message), remaining: Int, self: Subject(Message))
}
/// Messages the client responds to
pub type Message {
/// Kick off the client's request loop
Start
/// Internal message to continue sending the next request
Continue
}
/// A small pool of keys the client randomly picks from
const keys = #("a", "b", "c", "d", "e")
/// Pick a random key from the pool
fn random_key() -> String {
case int.random(5) {
0 -> keys.0
1 -> keys.1
2 -> keys.2
3 -> keys.3
_ -> keys.4
}
}
/// Pick a random value
fn random_value() -> String {
"val_" <> int.to_string(int.random(100))
}
/// Handle incoming messages
fn handle_message(state: State, message: Message) -> actor.Next(State, Message) {
case message {
Start -> {
io.println("[client] Starting — will send 5 requests")
send_next_request(state)
}
Continue -> {
send_next_request(state)
}
}
}
/// Send the next random request to the leader via Raft
fn send_next_request(state: State) -> actor.Next(State, Message) {
case state.remaining {
0 -> {
io.println("[client] Finished all 5 requests")
actor.stop()
}
n -> {
// Randomly choose between get (0), put (1), and delete (2)
case int.random(3) {
0 -> {
let key = random_key()
case node.get(state.leader, key) {
Ok(value) ->
io.println(
"[client] GET \"" <> key <> "\" -> \"" <> value <> "\"",
)
Error(reason) ->
io.println("[client] GET \"" <> key <> "\" -> " <> reason)
}
}
1 -> {
let key = random_key()
let value = random_value()
case node.put(state.leader, key, value) {
types.OpOk ->
io.println(
"[client] PUT \"" <> key <> "\" = \"" <> value <> "\" -> OK",
)
types.OpError(reason) ->
io.println(
"[client] PUT \""
<> key
<> "\" = \""
<> value
<> "\" -> "
<> reason,
)
}
}
_ -> {
let key = random_key()
case node.delete(state.leader, key) {
types.OpOk -> io.println("[client] DELETE \"" <> key <> "\" -> OK")
types.OpError(reason) ->
io.println("[client] DELETE \"" <> key <> "\" -> " <> reason)
}
}
}
// Schedule next request
process.send(state.self, Continue)
actor.continue(State(..state, remaining: n - 1))
}
}
}
/// Start a client actor that will send 5 random requests to the leader node
pub fn start(
leader_subject: Subject(node.Message),
) -> Result(Subject(Message), actor.StartError) {
actor.new_with_initialiser(1000, fn(self) {
let state = State(leader: leader_subject, remaining: 5, self: self)
actor.initialised(state)
|> actor.returning(self)
|> Ok
})
|> actor.on_message(handle_message)
|> actor.start
|> result.map(fn(started) { started.data })
}
File created successfully at: /Users/apanda/code/agent-spec-code/raft_kv/src/raft_kv/client.gleam
import argv
import gleam/erlang/process
import gleam/int
import gleam/io
import gleam/list
import gleam/result
import raft_kv/client
import raft_kv/node
import tom
/// Helper to create a list [1, 2, ..., n]
fn range_list(n: Int) -> List(Int) {
int.range(1, n + 1, [], fn(acc, i) { [i, ..acc] })
|> list.reverse
}
/// Read the config file and return (num_nodes, num_clients)
fn read_config(path: String) -> #(Int, Int) {
let assert Ok(content) = read_file(path)
let assert Ok(parsed) = tom.parse(content)
let num_nodes =
tom.get_int(parsed, ["num_nodes"])
|> result.unwrap(5)
let num_clients =
tom.get_int(parsed, ["num_clients"])
|> result.unwrap(3)
#(num_nodes, num_clients)
}
/// Read a file as a string (using Erlang's file module)
@external(erlang, "file", "read_file")
fn do_read_file(path: String) -> Result(BitArray, dynamic)
import gleam/bit_array
fn read_file(path: String) -> Result(String, Nil) {
case do_read_file(path) {
Ok(bits) -> bit_array.to_string(bits) |> result.nil_error
Error(_) -> Error(Nil)
}
}
pub fn main() -> Nil {
// Determine config file path from args or default
let config_path = case argv.load().arguments {
[path, ..] -> path
[] -> "config.toml"
}
let #(num_nodes, num_clients) = read_config(config_path)
io.println(
"Config: "
<> int.to_string(num_nodes)
<> " nodes, "
<> int.to_string(num_clients)
<> " clients",
)
// Start N Raft nodes
let nodes =
range_list(num_nodes)
|> list.map(fn(i) {
let assert Ok(n) = node.start(i, num_nodes)
io.println("Started node " <> int.to_string(i))
#(i, n)
})
// Send SetPeers to each node with all other nodes
list.each(nodes, fn(node_pair) {
let #(id, subject) = node_pair
let peers = list.filter(nodes, fn(p) { p.0 != id })
process.send(subject, node.SetPeers(peers))
})
io.println("All peers configured")
// Trigger election on node 1
let assert Ok(#(_, leader_subject)) =
list.find(nodes, fn(n) { n.0 == 1 })
process.send(leader_subject, node.StartElection)
// Small sleep to let election complete
process.sleep(200)
io.println("Election complete, starting clients")
// Start clients targeting node 1 (the leader)
let clients =
range_list(num_clients)
|> list.map(fn(i) {
let assert Ok(c) = client.start(leader_subject)
io.println("Started client " <> int.to_string(i))
c
})
// Tell each client to begin sending requests
list.each(clients, fn(c) { process.send(c, client.Start) })
io.println(
"All " <> int.to_string(num_clients) <> " clients started sending requests",
)
// Wait for clients to finish
process.sleep(3000)
io.println("Done")
}
<tool_use_error>File has not been read yet. Read it first before writing to it.</tool_use_error>
import gleam/erlang/process
import gleeunit
import raft_kv/node
import raft_kv/types
pub fn main() -> Nil {
gleeunit.main()
}
pub fn raft_put_get_test() {
// Start 3 nodes
let assert Ok(n1) = node.start(1, 3)
let assert Ok(n2) = node.start(2, 3)
let assert Ok(n3) = node.start(3, 3)
// Configure peers
process.send(n1, node.SetPeers([#(2, n2), #(3, n3)]))
process.send(n2, node.SetPeers([#(1, n1), #(3, n3)]))
process.send(n3, node.SetPeers([#(1, n1), #(2, n2)]))
// Elect node 1 as leader
process.send(n1, node.StartElection)
process.sleep(100)
// Test KV operations
let assert types.OpOk = node.put(n1, "x", "hello")
let assert Ok("hello") = node.get(n1, "x")
let assert types.OpError(_) = node.put(n1, "x", "world")
let assert types.OpOk = node.delete(n1, "x")
let assert Error(_) = node.get(n1, "x")
let assert types.OpError(_) = node.delete(n1, "x")
}
<tool_use_error>File has not been read yet. Read it first before writing to it.</tool_use_error>
1→import gleam/io
2→
3→pub fn main() -> Nil {
4→ io.println("Hello from raft_kv!")
5→}
6→{
"file_path": "/Users/apanda/code/agent-spec-code/raft_kv/test/raft_kv_test.gleam"
} 1→import gleeunit
2→
3→pub fn main() -> Nil {
4→ gleeunit.main()
5→}
6→
7→// gleeunit test functions end in `_test`
8→pub fn hello_world_test() {
9→ let name = "Joe"
10→ let greeting = "Hello, " <> name <> "!"
11→
12→ assert greeting == "Hello, Joe!"
13→}
14→import argv
import gleam/bit_array
import gleam/erlang/process
import gleam/int
import gleam/io
import gleam/list
import gleam/result
import raft_kv/client
import raft_kv/node
import tom
/// Helper to create a list [1, 2, ..., n]
fn range_list(n: Int) -> List(Int) {
int.range(1, n + 1, [], fn(acc, i) { [i, ..acc] })
|> list.reverse
}
/// Read a file as a string (using Erlang's file module)
@external(erlang, "file", "read_file")
fn do_read_file(path: String) -> Result(BitArray, dynamic)
fn read_file(path: String) -> Result(String, Nil) {
case do_read_file(path) {
Ok(bits) -> bit_array.to_string(bits) |> result.nil_error
Error(_) -> Error(Nil)
}
}
/// Read the config file and return (num_nodes, num_clients)
fn read_config(path: String) -> #(Int, Int) {
let assert Ok(content) = read_file(path)
let assert Ok(parsed) = tom.parse(content)
let num_nodes =
tom.get_int(parsed, ["num_nodes"])
|> result.unwrap(5)
let num_clients =
tom.get_int(parsed, ["num_clients"])
|> result.unwrap(3)
#(num_nodes, num_clients)
}
pub fn main() -> Nil {
// Determine config file path from args or default
let config_path = case argv.load().arguments {
[path, ..] -> path
[] -> "config.toml"
}
let #(num_nodes, num_clients) = read_config(config_path)
io.println(
"Config: "
<> int.to_string(num_nodes)
<> " nodes, "
<> int.to_string(num_clients)
<> " clients",
)
// Start N Raft nodes
let nodes =
range_list(num_nodes)
|> list.map(fn(i) {
let assert Ok(n) = node.start(i, num_nodes)
io.println("Started node " <> int.to_string(i))
#(i, n)
})
// Send SetPeers to each node with all other nodes
list.each(nodes, fn(node_pair) {
let #(id, subject) = node_pair
let peers = list.filter(nodes, fn(p) { p.0 != id })
process.send(subject, node.SetPeers(peers))
})
io.println("All peers configured")
// Trigger election on node 1
let assert Ok(#(_, leader_subject)) =
list.find(nodes, fn(n) { n.0 == 1 })
process.send(leader_subject, node.StartElection)
// Small sleep to let election complete
process.sleep(200)
io.println("Election complete, starting clients")
// Start clients targeting node 1 (the leader)
let clients =
range_list(num_clients)
|> list.map(fn(i) {
let assert Ok(c) = client.start(leader_subject)
io.println("Started client " <> int.to_string(i))
c
})
// Tell each client to begin sending requests
list.each(clients, fn(c) { process.send(c, client.Start) })
io.println(
"All " <> int.to_string(num_clients) <> " clients started sending requests",
)
// Wait for clients to finish
process.sleep(3000)
io.println("Done")
}
The file /Users/apanda/code/agent-spec-code/raft_kv/src/raft_kv.gleam has been updated successfully.
import gleam/erlang/process
import gleeunit
import raft_kv/node
import raft_kv/types
pub fn main() -> Nil {
gleeunit.main()
}
pub fn raft_put_get_test() {
// Start 3 nodes
let assert Ok(n1) = node.start(1, 3)
let assert Ok(n2) = node.start(2, 3)
let assert Ok(n3) = node.start(3, 3)
// Configure peers
process.send(n1, node.SetPeers([#(2, n2), #(3, n3)]))
process.send(n2, node.SetPeers([#(1, n1), #(3, n3)]))
process.send(n3, node.SetPeers([#(1, n1), #(2, n2)]))
// Elect node 1 as leader
process.send(n1, node.StartElection)
process.sleep(100)
// Test KV operations
let assert types.OpOk = node.put(n1, "x", "hello")
let assert Ok("hello") = node.get(n1, "x")
let assert types.OpError(_) = node.put(n1, "x", "world")
let assert types.OpOk = node.delete(n1, "x")
let assert Error(_) = node.get(n1, "x")
let assert types.OpError(_) = node.delete(n1, "x")
}
The file /Users/apanda/code/agent-spec-code/raft_kv/test/raft_kv_test.gleam has been updated successfully.
Exit code 1 Compiling argv Compiling gleam_stdlib Compiling gleam_erlang Compiling gleam_otp Compiling gleam_time Compiling gleeunit Compiling tom Compiling raft_kv error: Unknown module value ┌─ /Users/apanda/code/agent-spec-code/raft_kv/src/raft_kv.gleam:24:53 │ 24 │ Ok(bits) -> bit_array.to_string(bits) |> result.nil_error │ ^^^^^^^^^ Did you mean `is_error`? The module `gleam/result` does not have a `nil_error` value.
Ok(bits) -> bit_array.to_string(bits) |> result.nil_error
Ok(bits) ->
case bit_array.to_string(bits) {
Ok(s) -> Ok(s)
Error(_) -> Error(Nil)
}The file /Users/apanda/code/agent-spec-code/raft_kv/src/raft_kv.gleam has been updated successfully.
Compiled in 0.02s
Running raft_kv_test.main
[node 1] Starting
[node 2] Starting
[node 3] Starting
[node 3] Peers configured (2 peers)
[node 2] Peers configured (2 peers)
[node 1] Peers configured (2 peers)
[node 1] Starting election for term 1
[node 2] Granting vote to 1 for term 1
[node 1] Received vote from node 2
[node 3] Granting vote to 1 for term 1
[node 1] Received vote from node 3
[node 1] Election result: 3 votes (need 2)
[node 1] Became LEADER for term 1
[node 1] Appending entry at index 1 (term 1)
[node 2] AppendEntries OK from leader 1, match_index=1
[node 1] AppendEntries ACK from node 2 (match=1)
[node 3] AppendEntries OK from leader 1, match_index=1
[node 1] AppendEntries ACK from node 3 (match=1)
[node 1] Replication: 3/2 acks
[node 1] PUT "x" = "hello" -> OK
[node 2] CommitNotification: commit_index updated to 1
[node 3] CommitNotification: commit_index updated to 1
[node 1] Appending entry at index 2 (term 1)
[node 2] slot 1: PUT "x" = "hello" -> OK
[node 3] slot 1: PUT "x" = "hello" -> OK
[node 2] AppendEntries OK from leader 1, match_index=2
[node 1] AppendEntries ACK from node 2 (match=2)
[node 3] AppendEntries OK from leader 1, match_index=2
[node 1] AppendEntries ACK from node 3 (match=2)
[node 1] Replication: 3/2 acks
[node 1] GET "x" -> "hello"
[node 2] CommitNotification: commit_index updated to 2
[node 3] CommitNotification: commit_index updated to 2
[node 1] Appending entry at index 3 (term 1)
[node 2] slot 2: GET "x" -> "hello"
[node 3] slot 2: GET "x" -> "hello"
[node 2] AppendEntries OK from leader 1, match_index=3
[node 1] AppendEntries ACK from node 2 (match=3)
[node 3] AppendEntries OK from leader 1, match_index=3
[node 1] AppendEntries ACK from node 3 (match=3)
[node 1] Replication: 3/2 acks
[node 1] PUT "x" -> REJECTED (key exists)
[node 2] CommitNotification: commit_index updated to 3
[node 3] CommitNotification: commit_index updated to 3
[node 1] Appending entry at index 4 (term 1)
[node 2] slot 3: PUT "x" -> REJECTED (key exists)
[node 3] slot 3: PUT "x" -> REJECTED (key exists)
[node 2] AppendEntries OK from leader 1, match_index=4
[node 1] AppendEntries ACK from node 2 (match=4)
[node 3] AppendEntries OK from leader 1, match_index=4
[node 1] AppendEntries ACK from node 3 (match=4)
[node 1] Replication: 3/2 acks
[node 1] DELETE "x" -> OK
[node 2] CommitNotification: commit_index updated to 4
[node 3] CommitNotification: commit_index updated to 4
[node 1] Appending entry at index 5 (term 1)
[node 2] slot 4: DELETE "x" -> OK
[node 3] slot 4: DELETE "x" -> OK
[node 2] AppendEntries OK from leader 1, match_index=5
[node 1] AppendEntries ACK from node 2 (match=5)
[node 3] AppendEntries OK from leader 1, match_index=5
[node 1] AppendEntries ACK from node 3 (match=5)
[node 1] Replication: 3/2 acks
[node 1] GET "x" -> NOT FOUND
[node 2] CommitNotification: commit_index updated to 5
[node 3] CommitNotification: commit_index updated to 5
[node 1] Appending entry at index 6 (term 1)
[node 2] slot 5: GET "x" -> NOT FOUND
[node 3] slot 5: GET "x" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=6
[node 1] AppendEntries ACK from node 2 (match=6)
[node 3] AppendEntries OK from leader 1, match_index=6
[node 1] AppendEntries ACK from node 3 (match=6)
[node 1] Replication: 3/2 acks
[node 1] DELETE "x" -> NOT FOUND
[node 2] CommitNotification: commit_index updated to 6
[node 3] CommitNotification: commit_index updated to 6
[32m.[39m[32m
1 passed, no failures[39m Compiling raft_kv
Compiled in 0.28s
Running raft_kv.main
Config: 5 nodes, 3 clients
[node 1] Starting
Started node 1
[node 2] Starting
Started node 2
[node 3] Starting
Started node 3
[node 4] Starting
Started node 4
[node 5] Starting
Started node 5
All peers configured
[node 1] Peers configured (4 peers)
[node 2] Peers configured (4 peers)
[node 3] Peers configured (4 peers)
[node 4] Peers configured (4 peers)
[node 5] Peers configured (4 peers)
[node 1] Starting election for term 1
[node 2] Granting vote to 1 for term 1
[node 1] Received vote from node 2
[node 3] Granting vote to 1 for term 1
[node 1] Received vote from node 3
[node 4] Granting vote to 1 for term 1
[node 1] Received vote from node 4
[node 5] Granting vote to 1 for term 1
[node 1] Received vote from node 5
[node 1] Election result: 5 votes (need 3)
[node 1] Became LEADER for term 1
Election complete, starting clients
Started client 1
Started client 2
Started client 3
All 3 clients started sending requests
[client] Starting — will send 5 requests
[client] Starting — will send 5 requests
[client] Starting — will send 5 requests
[node 1] Appending entry at index 1 (term 1)
[node 2] AppendEntries OK from leader 1, match_index=1
[node 1] AppendEntries ACK from node 2 (match=1)
[node 3] AppendEntries OK from leader 1, match_index=1
[node 1] AppendEntries ACK from node 3 (match=1)
[node 4] AppendEntries OK from leader 1, match_index=1
[node 1] AppendEntries ACK from node 4 (match=1)
[node 5] AppendEntries OK from leader 1, match_index=1
[node 1] AppendEntries ACK from node 5 (match=1)
[node 1] Replication: 5/3 acks
[node 1] DELETE "a" -> NOT FOUND
[node 1] Appending entry at index 2 (term 1)
[client] DELETE "a" -> key not found: a
[node 2] CommitNotification: commit_index updated to 1
[node 3] CommitNotification: commit_index updated to 1
[node 4] CommitNotification: commit_index updated to 1
[node 5] CommitNotification: commit_index updated to 1
[node 2] slot 1: DELETE "a" -> NOT FOUND
[node 3] slot 1: DELETE "a" -> NOT FOUND
[node 4] slot 1: DELETE "a" -> NOT FOUND
[node 5] slot 1: DELETE "a" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=2
[node 1] AppendEntries ACK from node 2 (match=2)
[node 3] AppendEntries OK from leader 1, match_index=2
[node 1] AppendEntries ACK from node 3 (match=2)
[node 4] AppendEntries OK from leader 1, match_index=2
[node 1] AppendEntries ACK from node 4 (match=2)
[node 5] AppendEntries OK from leader 1, match_index=2
[node 1] AppendEntries ACK from node 5 (match=2)
[node 1] Replication: 5/3 acks
[node 1] PUT "b" = "val_84" -> OK
[node 1] Appending entry at index 3 (term 1)
[client] PUT "b" = "val_84" -> OK
[node 2] CommitNotification: commit_index updated to 2
[node 3] CommitNotification: commit_index updated to 2
[node 4] CommitNotification: commit_index updated to 2
[node 5] CommitNotification: commit_index updated to 2
[node 2] slot 2: PUT "b" = "val_84" -> OK
[node 3] slot 2: PUT "b" = "val_84" -> OK
[node 4] slot 2: PUT "b" = "val_84" -> OK
[node 5] slot 2: PUT "b" = "val_84" -> OK
[node 2] AppendEntries OK from leader 1, match_index=3
[node 1] AppendEntries ACK from node 2 (match=3)
[node 3] AppendEntries OK from leader 1, match_index=3
[node 1] AppendEntries ACK from node 3 (match=3)
[node 4] AppendEntries OK from leader 1, match_index=3
[node 1] AppendEntries ACK from node 4 (match=3)
[node 5] AppendEntries OK from leader 1, match_index=3
[node 1] AppendEntries ACK from node 5 (match=3)
[node 1] Replication: 5/3 acks
[node 1] DELETE "e" -> NOT FOUND
[node 1] Appending entry at index 4 (term 1)
[client] DELETE "e" -> key not found: e
[node 2] CommitNotification: commit_index updated to 3
[node 3] CommitNotification: commit_index updated to 3
[node 4] CommitNotification: commit_index updated to 3
[node 5] CommitNotification: commit_index updated to 3
[node 2] slot 3: DELETE "e" -> NOT FOUND
[node 3] slot 3: DELETE "e" -> NOT FOUND
[node 4] slot 3: DELETE "e" -> NOT FOUND
[node 5] slot 3: DELETE "e" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=4
[node 1] AppendEntries ACK from node 2 (match=4)
[node 3] AppendEntries OK from leader 1, match_index=4
[node 1] AppendEntries ACK from node 3 (match=4)
[node 4] AppendEntries OK from leader 1, match_index=4
[node 1] AppendEntries ACK from node 4 (match=4)
[node 5] AppendEntries OK from leader 1, match_index=4
[node 1] AppendEntries ACK from node 5 (match=4)
[node 1] Replication: 5/3 acks
[node 1] GET "e" -> NOT FOUND
[node 1] Appending entry at index 5 (term 1)
[client] GET "e" -> key not found: e
[node 2] CommitNotification: commit_index updated to 4
[node 3] CommitNotification: commit_index updated to 4
[node 4] CommitNotification: commit_index updated to 4
[node 5] CommitNotification: commit_index updated to 4
[node 2] slot 4: GET "e" -> NOT FOUND
[node 3] slot 4: GET "e" -> NOT FOUND
[node 4] slot 4: GET "e" -> NOT FOUND
[node 5] slot 4: GET "e" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=5
[node 1] AppendEntries ACK from node 2 (match=5)
[node 3] AppendEntries OK from leader 1, match_index=5
[node 1] AppendEntries ACK from node 3 (match=5)
[node 4] AppendEntries OK from leader 1, match_index=5
[node 1] AppendEntries ACK from node 4 (match=5)
[node 5] AppendEntries OK from leader 1, match_index=5
[node 1] AppendEntries ACK from node 5 (match=5)
[node 1] Replication: 5/3 acks
[node 1] PUT "b" -> REJECTED (key exists)
[node 1] Appending entry at index 6 (term 1)
[client] PUT "b" = "val_55" -> key already exists: b
[node 2] CommitNotification: commit_index updated to 5
[node 3] CommitNotification: commit_index updated to 5
[node 4] CommitNotification: commit_index updated to 5
[node 5] CommitNotification: commit_index updated to 5
[node 2] slot 5: PUT "b" -> REJECTED (key exists)
[node 3] slot 5: PUT "b" -> REJECTED (key exists)
[node 4] slot 5: PUT "b" -> REJECTED (key exists)
[node 5] slot 5: PUT "b" -> REJECTED (key exists)
[node 2] AppendEntries OK from leader 1, match_index=6
[node 1] AppendEntries ACK from node 2 (match=6)
[node 3] AppendEntries OK from leader 1, match_index=6
[node 1] AppendEntries ACK from node 3 (match=6)
[node 4] AppendEntries OK from leader 1, match_index=6
[node 1] AppendEntries ACK from node 4 (match=6)
[node 5] AppendEntries OK from leader 1, match_index=6
[node 1] AppendEntries ACK from node 5 (match=6)
[node 1] Replication: 5/3 acks
[node 1] GET "e" -> NOT FOUND
[node 1] Appending entry at index 7 (term 1)
[client] GET "e" -> key not found: e
[node 2] CommitNotification: commit_index updated to 6
[node 3] CommitNotification: commit_index updated to 6
[node 4] CommitNotification: commit_index updated to 6
[node 5] CommitNotification: commit_index updated to 6
[node 2] slot 6: GET "e" -> NOT FOUND
[node 3] slot 6: GET "e" -> NOT FOUND
[node 4] slot 6: GET "e" -> NOT FOUND
[node 5] slot 6: GET "e" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=7
[node 1] AppendEntries ACK from node 2 (match=7)
[node 3] AppendEntries OK from leader 1, match_index=7
[node 1] AppendEntries ACK from node 3 (match=7)
[node 4] AppendEntries OK from leader 1, match_index=7
[node 1] AppendEntries ACK from node 4 (match=7)
[node 5] AppendEntries OK from leader 1, match_index=7
[node 1] AppendEntries ACK from node 5 (match=7)
[node 1] Replication: 5/3 acks
[node 1] DELETE "b" -> OK
[node 1] Appending entry at index 8 (term 1)
[client] DELETE "b" -> OK
[node 2] CommitNotification: commit_index updated to 7
[node 3] CommitNotification: commit_index updated to 7
[node 4] CommitNotification: commit_index updated to 7
[node 5] CommitNotification: commit_index updated to 7
[node 2] slot 7: DELETE "b" -> OK
[node 3] slot 7: DELETE "b" -> OK
[node 4] slot 7: DELETE "b" -> OK
[node 5] slot 7: DELETE "b" -> OK
[node 2] AppendEntries OK from leader 1, match_index=8
[node 1] AppendEntries ACK from node 2 (match=8)
[node 3] AppendEntries OK from leader 1, match_index=8
[node 1] AppendEntries ACK from node 3 (match=8)
[node 4] AppendEntries OK from leader 1, match_index=8
[node 1] AppendEntries ACK from node 4 (match=8)
[node 5] AppendEntries OK from leader 1, match_index=8
[node 1] AppendEntries ACK from node 5 (match=8)
[node 1] Replication: 5/3 acks
[node 1] PUT "c" = "val_30" -> OK
[client] PUT "c" = "val_30" -> OK
[node 2] CommitNotification: commit_index updated to 8
[node 3] CommitNotification: commit_index updated to 8
[node 4] CommitNotification: commit_index updated to 8
[node 5] CommitNotification: commit_index updated to 8
[node 1] Appending entry at index 9 (term 1)
[node 2] slot 8: PUT "c" = "val_30" -> OK
[node 3] slot 8: PUT "c" = "val_30" -> OK
[node 4] slot 8: PUT "c" = "val_30" -> OK
[node 5] slot 8: PUT "c" = "val_30" -> OK
[node 2] AppendEntries OK from leader 1, match_index=9
[node 1] AppendEntries ACK from node 2 (match=9)
[node 3] AppendEntries OK from leader 1, match_index=9
[node 1] AppendEntries ACK from node 3 (match=9)
[node 4] AppendEntries OK from leader 1, match_index=9
[node 1] AppendEntries ACK from node 4 (match=9)
[node 5] AppendEntries OK from leader 1, match_index=9
[node 1] AppendEntries ACK from node 5 (match=9)
[node 1] Replication: 5/3 acks
[node 1] DELETE "b" -> NOT FOUND
[node 1] Appending entry at index 10 (term 1)
[client] DELETE "b" -> key not found: b
[node 2] CommitNotification: commit_index updated to 9
[node 3] CommitNotification: commit_index updated to 9
[node 4] CommitNotification: commit_index updated to 9
[node 5] CommitNotification: commit_index updated to 9
[node 2] slot 9: DELETE "b" -> NOT FOUND
[node 3] slot 9: DELETE "b" -> NOT FOUND
[node 4] slot 9: DELETE "b" -> NOT FOUND
[node 5] slot 9: DELETE "b" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=10
[node 1] AppendEntries ACK from node 2 (match=10)
[node 3] AppendEntries OK from leader 1, match_index=10
[node 1] AppendEntries ACK from node 3 (match=10)
[node 4] AppendEntries OK from leader 1, match_index=10
[node 1] AppendEntries ACK from node 4 (match=10)
[node 5] AppendEntries OK from leader 1, match_index=10
[node 1] AppendEntries ACK from node 5 (match=10)
[node 1] Replication: 5/3 acks
[node 1] DELETE "c" -> OK
[node 1] Appending entry at index 11 (term 1)
[client] DELETE "c" -> OK
[node 2] CommitNotification: commit_index updated to 10
[node 3] CommitNotification: commit_index updated to 10
[node 4] CommitNotification: commit_index updated to 10
[node 5] CommitNotification: commit_index updated to 10
[node 2] slot 10: DELETE "c" -> OK
[node 3] slot 10: DELETE "c" -> OK
[node 4] slot 10: DELETE "c" -> OK
[node 5] slot 10: DELETE "c" -> OK
[node 2] AppendEntries OK from leader 1, match_index=11
[node 1] AppendEntries ACK from node 2 (match=11)
[node 3] AppendEntries OK from leader 1, match_index=11
[node 1] AppendEntries ACK from node 3 (match=11)
[node 4] AppendEntries OK from leader 1, match_index=11
[node 1] AppendEntries ACK from node 4 (match=11)
[node 5] AppendEntries OK from leader 1, match_index=11
[node 1] AppendEntries ACK from node 5 (match=11)
[node 1] Replication: 5/3 acks
[node 1] DELETE "c" -> NOT FOUND
[node 1] Appending entry at index 12 (term 1)
[client] DELETE "c" -> key not found: c
[node 2] CommitNotification: commit_index updated to 11
[node 3] CommitNotification: commit_index updated to 11
[node 4] CommitNotification: commit_index updated to 11
[node 5] CommitNotification: commit_index updated to 11
[node 2] slot 11: DELETE "c" -> NOT FOUND
[node 3] slot 11: DELETE "c" -> NOT FOUND
[node 4] slot 11: DELETE "c" -> NOT FOUND
[node 5] slot 11: DELETE "c" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=12
[node 1] AppendEntries ACK from node 2 (match=12)
[node 3] AppendEntries OK from leader 1, match_index=12
[node 1] AppendEntries ACK from node 3 (match=12)
[node 4] AppendEntries OK from leader 1, match_index=12
[node 1] AppendEntries ACK from node 4 (match=12)
[node 5] AppendEntries OK from leader 1, match_index=12
[node 1] AppendEntries ACK from node 5 (match=12)
[node 1] Replication: 5/3 acks
[node 1] GET "b" -> NOT FOUND
[node 1] Appending entry at index 13 (term 1)
[client] GET "b" -> key not found: b
[node 2] CommitNotification: commit_index updated to 12
[node 3] CommitNotification: commit_index updated to 12
[node 4] CommitNotification: commit_index updated to 12
[node 5] CommitNotification: commit_index updated to 12
[node 2] slot 12: GET "b" -> NOT FOUND
[node 3] slot 12: GET "b" -> NOT FOUND
[node 4] slot 12: GET "b" -> NOT FOUND
[node 5] slot 12: GET "b" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=13
[node 1] AppendEntries ACK from node 2 (match=13)
[node 3] AppendEntries OK from leader 1, match_index=13
[node 1] AppendEntries ACK from node 3 (match=13)
[node 4] AppendEntries OK from leader 1, match_index=13
[node 1] AppendEntries ACK from node 4 (match=13)
[node 5] AppendEntries OK from leader 1, match_index=13
[node 1] AppendEntries ACK from node 5 (match=13)
[node 1] Replication: 5/3 acks
[node 1] GET "d" -> NOT FOUND
[node 1] Appending entry at index 14 (term 1)
[client] GET "d" -> key not found: d
[node 2] CommitNotification: commit_index updated to 13
[node 3] CommitNotification: commit_index updated to 13
[node 4] CommitNotification: commit_index updated to 13
[node 5] CommitNotification: commit_index updated to 13
[client] Finished all 5 requests
[node 2] slot 13: GET "d" -> NOT FOUND
[node 3] slot 13: GET "d" -> NOT FOUND
[node 4] slot 13: GET "d" -> NOT FOUND
[node 5] slot 13: GET "d" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=14
[node 1] AppendEntries ACK from node 2 (match=14)
[node 3] AppendEntries OK from leader 1, match_index=14
[node 1] AppendEntries ACK from node 3 (match=14)
[node 4] AppendEntries OK from leader 1, match_index=14
[node 1] AppendEntries ACK from node 4 (match=14)
[node 5] AppendEntries OK from leader 1, match_index=14
[node 1] AppendEntries ACK from node 5 (match=14)
[node 1] Replication: 5/3 acks
[node 1] DELETE "b" -> NOT FOUND
[node 1] Appending entry at index 15 (term 1)
[client] DELETE "b" -> key not found: b
[node 2] CommitNotification: commit_index updated to 14
[node 3] CommitNotification: commit_index updated to 14
[node 4] CommitNotification: commit_index updated to 14
[node 5] CommitNotification: commit_index updated to 14
[client] Finished all 5 requests
[node 2] slot 14: DELETE "b" -> NOT FOUND
[node 3] slot 14: DELETE "b" -> NOT FOUND
[node 4] slot 14: DELETE "b" -> NOT FOUND
[node 5] slot 14: DELETE "b" -> NOT FOUND
[node 2] AppendEntries OK from leader 1, match_index=15
[node 1] AppendEntries ACK from node 2 (match=15)
[node 3] AppendEntries OK from leader 1, match_index=15
[node 1] AppendEntries ACK from node 3 (match=15)
[node 4] AppendEntries OK from leader 1, match_index=15
[node 1] AppendEntries ACK from node 4 (match=15)
[node 5] AppendEntries OK from leader 1, match_index=15
[node 1] AppendEntries ACK from node 5 (match=15)
[node 1] Replication: 5/3 acks
[node 1] GET "a" -> NOT FOUND
[client] GET "a" -> key not found: a
[node 2] CommitNotification: commit_index updated to 15
[node 3] CommitNotification: commit_index updated to 15
[node 4] CommitNotification: commit_index updated to 15
[node 5] CommitNotification: commit_index updated to 15
[client] Finished all 5 requests
[node 2] slot 15: GET "a" -> NOT FOUND
[node 3] slot 15: GET "a" -> NOT FOUND
[node 4] slot 15: GET "a" -> NOT FOUND
[node 5] slot 15: GET "a" -> NOT FOUND
DoneEverything works. Here's a summary of what was created:
Files created in raft_kv/:
| File | Description |
|---|---|
config.toml |
Default config: 5 nodes, 3 clients |
src/raft_kv.gleam |
Main entry: reads TOML config, starts nodes, triggers election, runs clients |
src/raft_kv/types.gleam |
Shared types: Command, OpResult, LogEntry |
src/raft_kv/node.gleam |
Raft node actor — handles election (RequestVote), log replication (AppendEntries), commit notifications, and client requests (put/get/delete) |
src/raft_kv/client.gleam |
Client actor — sends 5 random requests to the leader |
test/raft_kv_test.gleam |
Tests: put, get existing, put duplicate (error), delete, get missing, delete missing (error) |
Verification results:
- gleam build — compiles cleanly
- gleam test — 1 test passed (KV semantics verified)
- gleam run — 5 nodes start, node 1 wins election, 3 clients issue requests with full Raft replication trace, followers apply committed entries
- gleam format — code is formatted
The code does not seem to include heartbeats, nor an election timeout. Can you check if I am mistaken about this, and if so point me to where they are?
You're correct — the implementation has neither heartbeats nor election timeouts. Node 1's election is triggered explicitly by main via a StartElection message, and there's no periodic heartbeat from the leader to followers. This works for the emulation (since there are no failures), but these are core Raft mechanisms that are missing.
1→# raft_kv
2→
3→[](https://hex.pm/packages/raft_kv)
4→[](https://hexdocs.pm/raft_kv/)
5→
6→```sh
7→gleam add raft_kv@1
8→```
9→```gleam
10→import raft_kv
11→
12→pub fn main() -> Nil {
13→ // TODO: An example of the project in use
14→}
15→```
16→
17→Further documentation can be found at <https://hexdocs.pm/raft_kv>.
18→
19→## Development
20→
21→```sh
22→gleam run # Run the project
23→gleam test # Run the tests
24→```
25→# raft_kv An emulation of a replicated key-value store using the Raft consensus protocol, implemented in Gleam with OTP actors. ## Running ```sh gleam run # Run with default config (config.toml) gleam run -- path.toml # Run with a custom config file gleam test # Run the tests ``` ## Configuration Edit `config.toml` to set the number of nodes and clients: ```toml num_nodes = 5 num_clients = 3 ``` ## Simplifications This emulation omits **heartbeats** and **election timeouts**, which are core mechanisms in the full Raft protocol. In real Raft: - The leader periodically sends empty AppendEntries RPCs (heartbeats) to followers to maintain authority and prevent new elections. - Followers start a new election if they don't receive a heartbeat within a randomized election timeout, which is how the system recovers from leader failure. These are omitted here because this is a failure-free emulation: the leader is designated at startup (node 1 sends a single `StartElection` message and wins), no nodes crash, and there is no need for leader recovery. Including heartbeats and election timeouts would add complexity without changing the observable behavior of the emulation. The focus is on demonstrating Raft's log replication and commit mechanics rather than its leader election recovery path.
The file /Users/apanda/code/agent-spec-code/raft_kv/README.md has been updated successfully.
Done. The README now documents the omission of heartbeats and election timeouts, along with the reasoning: this is a failure-free emulation focused on log replication mechanics, so leader recovery isn't needed.
cd /Users/apanda/code/agent-spec-code && git diff --stat
cd /Users/apanda/code/agent-spec-code && git log --oneline -5
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