[backport 3.2] raft: fix election deadlock when nodes have election_mode off#12020
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sergepetrenko merged 1 commit intorelease/3.2from Nov 10, 2025
Merged
[backport 3.2] raft: fix election deadlock when nodes have election_mode off#12020sergepetrenko merged 1 commit intorelease/3.2from
sergepetrenko merged 1 commit intorelease/3.2from
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Forcing nodes with `is_enabled=false` to always broadcast `is_leader_seen=false`. This allows candidate nodes to immediately clear witness map bits for non-participating nodes, enabling elections to proceed with only active participants. Closes #12018 NO_DOC=bugfix (cherry picked from commit 214b54c)
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(This PR is a backport of #11981 to
release/3.2to a future3.2.3release.)Closes #12018
When instances with
election_mode=offexist in a replicaset, they continue to broadcastis_leader_seen=trueeven after the leader dies. (Their death detection timers never start since RAFT is disabled for them). This causes theleader_witness_mapbits for these hosts to remain set indefinitely on candidate nodes, blocking elections since the pre-vote protection check requiresleader_witness_map==0.The root cause is that
election_mode=offnodes cannot be distinguished from active voters in RAFT messages. Both report statefollowerwithis_leader_seenbased on local state, butelection_mode=offnodes never update their view since heartbeat processing exits early when raft is disabled.This fix forces nodes with
election_mode=offto always broadcastis_leader_seen=false. This allows candidate nodes to immediately clear witness map bits for non-participating nodes, enabling elections to proceed with only active participants.Is this the right approach or have I missed anything?