fix: configurable cluster log-channel term length (oms#73 CI starvation)#102
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…rvation) The consensus LOG channel was the one channel TRANSPORT_TERM_LENGTH never reached: Aeron's LOG_CHANNEL_DEFAULT (term-length=64m) applied regardless, and every follower catch-up replay mapped + zero-faulted a fresh non-sparse 192MB (3x64m) buffer. On small CI runners the election/rejoin window spends whole connect-timeouts faulting buffers, surfacing as ReplaySession 'no connection established' storms and the openexch/oms#73 e2e failures (both 'no new leader' and 'node0 never rejoins' modes). New TRANSPORT_LOG_TERM_LENGTH / transport.log.term.length knob, default 64m = prod behavior unchanged. The oms e2e harness sets it to 4m: verified locally, peak e2e /dev/shm 1443MB -> 900MB, 192MB buffers gone, suite green. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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…the oms#73 fix) (#127) Archive.Context.replicationChannel and ConsensusModule.Context.replicationChannel both built endpoint-only URIs, so Aeron's 64m default term-length applied to every replication/catch-up replay regardless of TRANSPORT_LOG_TERM_LENGTH. Same starvation class as oms#73: on small hosts (CI runners) a rejoining node maps a fresh non-sparse 3-term buffer per replay and elections time out - match PR #102 fixed the log channel but left both replication channels on the default. This is the root cause of the oms e2e failures (ArchiveException: no connection established for replayChannel=...term-length=64m). Prod behavior unchanged: logTermLength() defaults to 64m; CI sets the env knob. Claude-Session: https://claude.ai/code/session_012ddjgSUkUdVdBtBh4b2hde Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
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Companion to openexch/oms#73 (e2e failover suite red on CI).
Mechanism
TRANSPORT_TERM_LENGTHnever covered the consensus LOG channel: match never setslogChannel, so Aeron'sLOG_CHANNEL_DEFAULT(aeron:udp?term-length=64m) applied. Follower catch-up replay inherits it, so every replay attempt maps and zero-faults a non-sparse 192MB (3×64m) buffer, lingering 5s on failure. On a small CI runner the election window degenerates into ReplaySessionno connection establishedstorms — the signature of both oms#73 failure modes (no new leader after kill; node0 never rejoins).Change
TransportConfig.logTermLength()— envTRANSPORT_LOG_TERM_LENGTH/ proptransport.log.term.length, default 64m = prod behavior unchanged.AeronClustersetsconsensusModuleContext().logChannel(aeron:udp?term-length=<value>)next to the other env-driven channel config.Evidence (local, 24-core box)
TRANSPORT_LOG_TERM_LENGTH=4m: peak 900MB, largest file 48MB (16m IPC buffers), suite PASS.The oms harness PR (follows) sets 4m for e2e; its CI run builds match from main and is the end-to-end validation.
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