From: | Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> |
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To: | pgsql-hackers(at)postgresql(dot)org |
Subject: | xact_start for walsender & logical decoding not updated |
Date: | 2019-12-09 23:44:09 |
Message-ID: | 20191209234409.exe7osmyalwkt5j4@development |
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Lists: | pgsql-hackers |
Hi,
I think there's a minor bug in pg_stat_activity tracking of walsender
processes. The issue is that xact_start is only updated at the very
beginning when the walsender starts (so it's almost exactly equal to
backend_start) and then just flips between NULL and that value.
Reproducing this is trivial - just create a publication/subscription
with the built-in logical replication, and run arbitrary workload.
You'll see that the xact_start value never changes.
I think the right fix is calling SetCurrentStatementStartTimestamp()
right before StartTransactionCommand() in ReorderBufferCommit, per the
attached patch.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Attachment | Content-Type | Size |
---|---|---|
reorderbuffer-timestamp-fix.patch | text/plain | 517 bytes |
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