test(raft): E2E replicated writes; wire SQL path to raft node
- Fix runTcpServer to run the already-wired Server (raftNode was assigned on a different instance that never accepted clients). - Cap raft peer connect at 200ms and fan out heartbeats in parallel so a dead peer cannot stall AppendEntries to the live majority. - Add raft_writes_e2e_test: 3-node write replication, follower rejection, and post-failover writes; wire into nimble test + gitignore.
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## Raft replicated writes E2E — real 3-node cluster over the TCP transport.
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## Starts three actual build/baradadb processes, writes through the leader
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## (exercising the raft commit wait), verifies followers apply committed
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## entries, rejects follower writes, and writes again after failover.
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## Process-management conventions follow tests/raft_e2e_test.nim; client
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## access follows tests/nimforum_smoke_test.nim.
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##
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## NOTE: CREATE TABLE produces no keyValuePairs (schema DDL is out of scope
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## for raft replication), so followers never learn the table from the log.
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## The test therefore creates the table locally on ALL nodes — CREATE TABLE
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## is not classified as a raft write (isWrite covers DML only), so followers
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## accept it — and tests ROW replication only.
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import std/unittest
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import std/osproc
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import std/os
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import std/strtabs
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import std/strutils
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import std/sequtils
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import std/times
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import std/net
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import std/posix
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import ../adaptors/nim/baradb_sqlite as sqlite
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const
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BinaryPath = "./build/baradadb"
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LeaderMarker = "became leader"
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type
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NodeProc = object
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id: string
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clientPort: int
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p: Process
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dataDir: string
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output: string
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alive: bool
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proc drainOutput(n: var NodeProc) =
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## Reads whatever the child has written so far. The pipe was set O_NONBLOCK
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## at start, so this never blocks — a hung read is impossible here.
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var tmp: array[8192, char]
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while true:
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let count = posix.read(n.p.outputHandle.cint, tmp[0].addr, tmp.len)
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if count <= 0: break
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for i in 0 ..< count: n.output.add tmp[i]
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proc drainAll(nodes: var seq[NodeProc]) =
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for n in nodes.mitems:
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if n.p != nil: n.drainOutput()
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proc dumpAll(nodes: var seq[NodeProc]) =
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## Debuggability: on failure, everything the nodes said.
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nodes.drainAll()
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for n in nodes:
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echo "===== output of ", n.id, " (port ", n.clientPort, ") ====="
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echo n.output
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proc portOpen(port: int): bool =
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var s: Socket
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try:
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s = newSocket()
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s.connect("127.0.0.1", Port(port), timeout = 250)
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s.close()
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result = true
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except CatchableError:
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if s != nil: s.close()
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result = false
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proc killNode(n: var NodeProc) =
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if n.p != nil and n.alive:
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try:
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n.p.terminate()
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discard n.p.waitForExit()
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except CatchableError:
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discard
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n.alive = false
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proc leaderTerms(output: string): seq[int] =
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## All terms this node logged leadership for ("became leader for term T").
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var pos = 0
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while true:
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let idx = output.find(LeaderMarker, pos)
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if idx < 0: break
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let tIdx = output.find("term ", idx)
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if tIdx < 0: break
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let numStart = tIdx + 5
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var numEnd = numStart
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while numEnd < output.len and output[numEnd] in Digits: inc numEnd
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if numEnd > numStart:
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result.add(parseInt(output[numStart ..< numEnd]))
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pos = numEnd
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proc maxLeader(nodes: seq[NodeProc]): tuple[idx, term: int] =
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## Node that logged leadership for the highest term seen so far.
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result = (-1, 0)
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for i in 0 ..< nodes.len:
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for t in leaderTerms(nodes[i].output):
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if t > result.term: result = (i, t)
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proc drainFor(nodes: var seq[NodeProc], ms: int) =
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let start = getTime()
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while getTime() - start < initDuration(milliseconds = ms):
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nodes.drainAll()
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sleep(50)
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proc openClient(port: int): DbConn =
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## Connect with retries — the port may accept TCP before the DB is usable.
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for i in 0 ..< 50:
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try:
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return open("127.0.0.1:" & $port, "", "", "default")
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except CatchableError:
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sleep(100)
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raise newException(IOError, "cannot connect to port " & $port)
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proc waitForRow(port: int, name: string, deadlineSec: int): bool =
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## Poll SELECT on `port` until a row with `name` appears. Tolerates errors
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## (e.g. "unknown table" while schema has not been created yet) by retrying.
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let db = openClient(port)
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defer: db.close()
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let start = getTime()
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while getTime() - start < initDuration(seconds = deadlineSec):
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try:
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let rows = db.getAllRows(sql"SELECT * FROM rw_test")
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for row in rows:
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if row.len >= 2 and row[1] == name:
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return true
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except CatchableError:
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discard
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sleep(100)
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return false
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proc runWritesScenario() =
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## Fatal phase failures dump all captured node output, record a test
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## failure, and return; cleanup happens in the finally below either way.
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let tstamp = getTime().toUnix.int
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# Port bases: distinct from nimforum_smoke_test (35000+mod10000) and
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# raft_e2e_test (41000+mod5000). Client ports are spaced by 10 because the
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# server derives HTTP (port+440), WS (port+441) and gossip (raftPort+100)
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# ports — consecutive client ports collide.
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let cbase = 46000 + (tstamp mod 4000)
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let rbase = cbase + 100
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let peers = "n1@127.0.0.1:" & $(rbase + 1) &
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",n2@127.0.0.1:" & $(rbase + 2) &
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",n3@127.0.0.1:" & $(rbase + 3)
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var nodes: seq[NodeProc]
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for i in 1 .. 3:
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let id = "n" & $i
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let dataDir = getTempDir() / "baradb_raft_writes_e2e_" & $tstamp & "_" & id
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createDir(dataDir)
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var env = newStringTable()
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for key, val in envPairs():
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env[key] = val
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env["BARADB_PORT"] = $(cbase + i * 10)
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env["BARADB_RAFT_ENABLED"] = "true"
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env["BARADB_RAFT_PORT"] = $(rbase + i)
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env["BARADB_RAFT_NODE_ID"] = id
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env["BARADB_RAFT_PEERS"] = peers
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env["BARADB_DATA_DIR"] = dataDir
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env["BARADB_LOG_LEVEL"] = "info"
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let p = startProcess(BinaryPath, env = env,
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options = {poStdErrToStdOut, poDaemon})
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discard fcntl(p.outputHandle.cint, F_SETFL,
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fcntl(p.outputHandle.cint, F_GETFL) or O_NONBLOCK)
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nodes.add NodeProc(id: id, clientPort: cbase + i * 10, p: p,
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dataDir: dataDir, alive: true)
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try:
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# Readiness: all three client ports accept TCP connections (10s each).
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for i in 0 ..< nodes.len:
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let readyStart = getTime()
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var ok = false
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while getTime() - readyStart < initDuration(seconds = 10):
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if portOpen(nodes[i].clientPort):
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ok = true
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break
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sleep(100)
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if not ok:
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echo "node ", nodes[i].id, " never became ready"
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dumpAll(nodes)
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fail()
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return
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# Election: timeouts are 150-300ms, heartbeat 50ms — a leader should
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# emerge within ~2s; 10s deadline for margin.
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var elected = false
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let electStart = getTime()
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while getTime() - electStart < initDuration(seconds = 10):
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nodes.drainAll()
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if maxLeader(nodes).idx >= 0:
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elected = true
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break
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sleep(50)
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if not elected:
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echo "no leader elected within 10s"
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dumpAll(nodes)
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fail()
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return
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# Settle and require stability, same as raft_e2e_test.
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nodes.drainFor(2000)
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let (leaderIdx, leaderTerm) = maxLeader(nodes)
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nodes.drainFor(1000)
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let (stableIdx, stableTerm) = maxLeader(nodes)
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if stableIdx != leaderIdx or stableTerm != leaderTerm:
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echo "cluster unstable: leadership moved from ", nodes[leaderIdx].id,
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" (term ", leaderTerm, ") to ", nodes[stableIdx].id,
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" (term ", stableTerm, ")"
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dumpAll(nodes)
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fail()
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return
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echo "leader elected: ", nodes[leaderIdx].id, " (term ", leaderTerm, ")"
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# Schema: CREATE TABLE is not a raft write (DML only is), and its _schema
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# keys are not replicated — create the table locally on every node.
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for i in 0 ..< nodes.len:
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let db = openClient(nodes[i].clientPort)
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try:
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db.exec(sql"CREATE TABLE rw_test (id INT PRIMARY KEY, name STRING)")
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except CatchableError as e:
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echo "CREATE TABLE failed on ", nodes[i].id, ": ", e.msg
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dumpAll(nodes)
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fail()
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return
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db.close()
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let followerIdx = (if leaderIdx == 0: 1 else: 0)
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# Leader write: INSERT goes through the raft log and waits for majority
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# commit before responding (Task 2) — expect success.
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block:
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let db = openClient(nodes[leaderIdx].clientPort)
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try:
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db.exec(sql"INSERT INTO rw_test (id, name) VALUES (1, 'raft-row')")
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except CatchableError as e:
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echo "leader INSERT failed: ", e.msg
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dumpAll(nodes)
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fail()
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return
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db.close()
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echo "leader INSERT committed"
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# Follower visibility: applyCommand puts committed entries into the
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# follower's default DB — poll until the row shows up (5s deadline).
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if not waitForRow(nodes[followerIdx].clientPort, "raft-row", 5):
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echo "follower ", nodes[followerIdx].id,
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" never saw the replicated row within 5s"
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dumpAll(nodes)
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fail()
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return
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echo "row replicated to follower ", nodes[followerIdx].id
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# Follower rejection: DML on a follower must fail with "not leader".
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block:
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let db = openClient(nodes[followerIdx].clientPort)
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var rejected = false
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try:
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db.exec(sql"INSERT INTO rw_test (id, name) VALUES (99, 'nope')")
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except CatchableError as e:
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rejected = "not leader" in e.msg
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if not rejected:
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echo "follower INSERT failed but without 'not leader': ", e.msg
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db.close()
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if not rejected:
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echo "follower INSERT was not rejected with a 'not leader' error"
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dumpAll(nodes)
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fail()
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return
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echo "follower INSERT rejected with 'not leader'"
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# Failover: kill the leader. A survivor must accept a write once it wins
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# a new term (majority of the remaining 2-of-3). Log lines can thrash
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# across terms, so discover the new leader by probing INSERT rather than
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# relying solely on the first "became leader" line.
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killNode(nodes[leaderIdx])
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var newLeaderIdx = -1
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var writeErr = ""
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let foStart = getTime()
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while getTime() - foStart < initDuration(seconds = 15):
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nodes.drainAll()
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# Prefer the highest-term survivor when choosing who to probe first.
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var order: seq[int] = @[]
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var bestTerm = 0
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var bestIdx = -1
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for i in 0 ..< nodes.len:
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if i == leaderIdx: continue
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order.add(i)
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for t in leaderTerms(nodes[i].output):
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if t > bestTerm: (bestIdx, bestTerm) = (i, t)
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if bestIdx >= 0:
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# Probe the current highest-term node first.
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order = order.filterIt(it != bestIdx)
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order.insert(bestIdx, 0)
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for i in order:
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try:
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let db = openClient(nodes[i].clientPort)
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try:
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db.exec(sql"INSERT INTO rw_test (id, name) VALUES (2, 'after-failover')")
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newLeaderIdx = i
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finally:
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db.close()
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if newLeaderIdx >= 0: break
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except CatchableError as e:
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writeErr = e.msg
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# "not leader" / commit timeout / connection blips — keep probing.
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if newLeaderIdx >= 0: break
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sleep(150)
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if newLeaderIdx < 0:
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echo "no survivor accepted a post-failover write within 15s",
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(if writeErr.len > 0: " (last error: " & writeErr & ")" else: "")
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dumpAll(nodes)
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fail()
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return
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echo "failover complete: new leader ", nodes[newLeaderIdx].id,
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" accepted post-failover write"
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# The remaining follower (neither old nor new leader) must see the row.
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let remainingIdx = 3 - leaderIdx - newLeaderIdx
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if not waitForRow(nodes[remainingIdx].clientPort, "after-failover", 8):
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echo "remaining follower ", nodes[remainingIdx].id,
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" never saw the post-failover row within 8s"
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dumpAll(nodes)
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fail()
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return
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echo "post-failover row replicated to ", nodes[remainingIdx].id
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check leaderIdx != newLeaderIdx
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finally:
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for n in nodes.mitems:
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n.killNode()
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if n.p != nil: n.p.close()
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removeDir(n.dataDir)
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suite "Raft replicated writes E2E":
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test "writes replicate, followers reject, failover resumes writes":
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if not fileExists(BinaryPath):
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echo "[SKIP] ", BinaryPath, " missing — run `nimble test` (builds the server first)"
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skip()
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else:
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runWritesScenario()
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