Online DDL: identify VReplication retrying failure, terminate migration#9958
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shlomi-noach wants to merge 2 commits intovitessio:mainfrom
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Online DDL: identify VReplication retrying failure, terminate migration#9958shlomi-noach wants to merge 2 commits intovitessio:mainfrom
shlomi-noach wants to merge 2 commits intovitessio:mainfrom
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Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
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The only failing test is |
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On top of the fix in this PR, we also have #9973 which identifies specific error codes and completely fails the vreplication workflow on those errors. This PR then serves as a sort of "plan B" for when vreplication still insists on retrying and never makes progress. |
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implicitly merged by #9973 |
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Description
There's a set of errors that VReplication encounters, that it doesn't fail on, it just keeps retrying forever. Recently, #9538 introduced
time_heartbeat. By looking at bothtime_heartbeatandtime_updatedwe are able to determine whether a vreplication stream is making no progress. We look at the greater value of the two. If it is not making progress for X minutes, then vreplication is effectively not doing its work.
Online DDL executor now looks at that (greater of the two) value, persists it in
schema_migrations, and only updatesliveness_timestampof the (vitessstrategy) migration if it sees an increase in the value.What this means is in effect, if VReplication is stuck/retrying, then
liveness_timestampdoes not increase. In turn, the executor will see that the migration has not indicated liveness in quite a while, and will eventually (configured at 10min) terminate the migration and mark it asfailed.So this gives us a
10minreaction time to a hanging VReplication stream.Related Issue(s)
Tracking: #6926
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