Fix Snapshot Abort Not Waiting for Data Nodes (#58214)#58229
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original-brownbear merged 1 commit intoelastic:7.8from Jun 17, 2020
original-brownbear:58214-7.8
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Fix Snapshot Abort Not Waiting for Data Nodes (#58214)#58229original-brownbear merged 1 commit intoelastic:7.8from original-brownbear:58214-7.8
original-brownbear merged 1 commit intoelastic:7.8from
original-brownbear:58214-7.8
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This was a really subtle bug that we introduced a long time ago. If a shard snapshot is in aborted state but hasn't started snapshotting on a node we can only send the failed notification for it if the shard was actually supposed to execute on the local node. Without this fix, if shard snapshots were spread out across at least two data nodes (so that each data node does not have all the primaries) the abort would actually never wait on the data nodes. This isn't a big deal with uuid shard generations but could lead to potential corruption on S3 when using numeric shard generations (albeit very unlikely now that we have the 3 minute wait there). Another negative side-effect of this bug was that master would receive a lot more shard status update messages for aborted shards since each data node not assigned a primary would send one message for that primary.
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Pinging @elastic/es-distributed (:Distributed/Snapshot/Restore) |
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This was a really subtle bug that we introduced a long time ago.
If a shard snapshot is in aborted state but hasn't started snapshotting on a node
we can only send the failed notification for it if the shard was actually supposed
to execute on the local node.
Without this fix, if shard snapshots were spread out across at least two data nodes
(so that each data node does not have all the primaries) the abort would actually
never wait on the data nodes. This isn't a big deal with uuid shard generations
but could lead to potential corruption on S3 when using numeric shard generations
(albeit very unlikely now that we have the 3 minute wait there).
Another negative side-effect of this bug was that master would receive a lot more
shard status update messages for aborted shards since each data node not assigned
a primary would send one message for that primary.
backport of #58214