On Mon, 10 Jun 2024 at 15:10, Shlok Kyal <shlok.kyal....@gmail.com> wrote: > > On Thu, 6 Jun 2024 at 11:49, Kyotaro Horiguchi <horikyota....@gmail.com> > wrote: > > > > At Thu, 6 Jun 2024 12:49:45 +1000, Peter Smith <smithpb2...@gmail.com> > > wrote in > > > Hi, I have reproduced this multiple times now. > > > > > > I confirmed the initial post/steps from Alexander. i.e. The test > > > script provided [1] gets itself into a state where function > > > ReadPageInternal (called by XLogDecodeNextRecord and commented "Wait > > > for the next page to become available") constantly returns > > > XLREAD_FAIL. Ultimately the test times out because WalSndLoop() loops > > > forever, since it never calls WalSndDone() to exit the walsender > > > process. > > > > Thanks for the repro; I believe I understand what's happening here. > > > > During server shutdown, the latter half of the last continuation > > record may fail to be flushed. This is similar to what is described in > > the commit message of commit ff9f111bce. While shutting down, > > WalSndLoop() waits for XLogSendLogical() to consume WAL up to > > flushPtr, but in this case, the last record cannot complete without > > the continuation part starting from flushPtr, which is > > missing. However, in such cases, xlogreader.missingContrecPtr is set > > to the beginning of the missing part, but something similar to > > > > So, I believe the attached small patch fixes the behavior. I haven't > > come up with a good test script for this issue. Something like > > 026_overwrite_contrecord.pl might work, but this situation seems a bit > > more complex than what it handles. > > > > Versions back to 10 should suffer from the same issue and the same > > patch will be applicable without significant changes. > > I tested the changes for PG 12 to master as we do not support prior versions. > The patch applied successfully for master and PG 16. I ran the test > provided in [1] multiple times and it ran successfully each time. > The patch did not apply on PG 15. I did a similar change for PG 15 and > created a patch. I ran the test multiple times and it was successful > every time. > The patch did not apply on PG 14 to PG 12. I did a similar change in > each branch. But the tests did not pass in each branch. I, by mistake, applied wrong changes in PG 14 to PG 12. I tested again for all versions and the test ran successfully for all of them till PG12. I have also attached the patch which applies for PG14 to PG12.
Sorry for the inconvenience. Thanks and Regards, Shlok Kyal
v2-0001-Fix-infinite-loop-in-walsender-during-publisher-s.patch
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v2-0001-Fix-infinite-loop-in-walsender-during-publisher-s-PG-15.patch
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v2-0001-Fix-infinite-loop-in-walsender-during-publisher-s-PG-14.patch
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