Re: WAL recycled despite logical replication slot

Hi,

On September 20, 2019 5:45:34 AM PDT, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
>While testing something else (whether "terminating walsender process
>due to
>replication timeout" was happening spuriously), I had logical
>replication
>set up streaming a default pgbench transaction load, with the publisher
>being 13devel-e1c8743 and subscriber being 12BETA4. Eventually I
>started
>getting errors about requested wal segments being already removed:
>
>10863 sub idle 00000 2019-09-19 17:14:58.140 EDT LOG: starting logical
>decoding for slot "sub"
>10863 sub idle 00000 2019-09-19 17:14:58.140 EDT DETAIL: Streaming
>transactions committing after 79/EB0B17A0, reading WAL from
>79/E70736A0.
>10863 sub idle 58P01 2019-09-19 17:14:58.140 EDT ERROR: requested WAL
>segment 0000000100000079000000E7 has already been removed
>10863 sub idle 00000 2019-09-19 17:14:58.144 EDT LOG: disconnection:
>session time: 0:00:00.030 user=jjanes database=jjanes host=10.0.2.2
>port=40830
>
>It had been streaming for about 50 minutes before the error showed up,
>and
>it showed right when streaming was restarting after one of the
>replication
>timeouts.
>
>Is there an innocent explanation for this? I thought logical
>replication
>slots provided an iron-clad guarantee that WAL would be retained until
>it
>was no longer needed. I am just using pub/sub, none of the lower level
>stuff.

It indeed should. What's the content of
pg_replication_slot for that slot?

Andres
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