Benoit Tellier created JAMES-3679:
-------------------------------------
Summary: Solve tombstones warning for mailbox recent table
Key: JAMES-3679
URL: https://issues.apache.org/jira/browse/JAMES-3679
Project: James Server
Issue Type: Improvement
Components: mailbox
Reporter: Benoit Tellier
Fix For: 3.7.0
We noticed tombstone warnings on some tables namely firstunseen, mailboxrecent
and (less) messageidtable.
mailbox recent table is used to keep track of recent emails within a mailbox in
order to fasten SELECT (and avoid full reads of messageidtable). The behaviour
is to generally to clean up entries straight after reading them.
Hence we only have a few recent emails, but keep tumbstones for 10 days, hence
selets often have to cross many tumbstone.
However this property is interesting: if we can afford some false positives,
then we could aggressively decrease gc_grace_period to 0. This would cause
tumbstones to be disposed of at the first compaction, significantly reducing
their impact. The downside is that mis-synchronisation might lead to entries
re-appearing once deleted. Which is likely acceptable on some rare occasion for
mailbox recent. And such entries would eventually be cleaned up (as recent
entries are removed on SELECT)
We experimented gc_grace_period = 0 on one of our production plateform and no
longer see warnings for mailboxrecent table hance wanted to share this here.
Yet this approach can not be applied for other tables (firstunseen /
messageidtable)
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
