ZhaoYang created CASSANDRA-14930:
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Summary: decommission may cause timeout because messaging backlog
is cleared
Key: CASSANDRA-14930
URL: https://issues.apache.org/jira/browse/CASSANDRA-14930
Project: Cassandra
Issue Type: Bug
Components: Coordination, Core
Reporter: ZhaoYang
Assignee: ZhaoYang
Fix For: 3.0.x, 3.11.x
On a 3-node cluster with RF=2, decommissioning a node may cause quorum write
timeout because messaging backlog to decommissioned node is cleared via
{{Gossiper#removeEndpoint() -> OutboundTcpConnection#closeSocket()}}.
(Timeout is less likely to happen with RF=3, because we can afford one less
response)
{code:java}
What happened:
1. [WriteStage] before the leaving node is removed from tokenmetadata, the
write endpoints are generated ( leaving endpoint is included )
2. [GossipStage] the leaving node is removed from tokenmetadata, no more future
write handler will include leaving endpoints
3. [WriteStage] write handlers sends messages to messaging-service backlog
4. [GossipStage] messaging-service backlog is cleared, messages are not sent
and connection closed
5. [WriteStage] write time out
{code}
| patch |
|
[3.0|https://github.com/jasonstack/cassandra/commits/decommission_timeout_3.0]
|
|
[3.0|https://github.com/jasonstack/cassandra/commits/decommission_timeout_3.11]
|
We can avoid it by delaying to destroy messaging connection so that messages
are sent and responded. New messaging framework rewrite in {{Trunk}} avoids the
issues by not clearing messaging backlog.
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