On August 25, 2018 4:43:03 PM GMT+02:00, Andres Freund <andres@xxxxxxxxxxx> wrote: >On 2018-08-25 07:04:14 +0000, Julien Riou wrote: >> Hello, >> >> We have few highly available clusters with patroni managing >PostgreSQL >> 9.6 (pgdg on debian stretch). We use logical decoding with wal2json >to >> stream data to a remote platform. On a majority of clusters, it works >> like a charm. But for one, we have the following error right after >> decoding start: >> >> [1353-1] LOG: starting logical decoding for slot "*****" >> [1353-2] DETAIL: streaming transactions committing after >321/292C06F0, reading WAL from 321/28BA9898 >> [1354-1] LOG: logical decoding found consistent point at >321/28BA9898 >> [1354-2] DETAIL: There are no running transactions. >> [1355-1] ERROR: no known snapshots >> [1355-2] CONTEXT: slot "*****", output plugin "wal2json", in the >change callback, associated LSN 321/2A985A30 >> >> The only reference of the "no known snapshots" error is in PostgreSQL >source >> code: >> >https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/access/heap/tuptoaster.c;h=ade4bd142dfbd7ef3340495b06d1041e4032a17f;hb=ca3489e768990e32096f0f24d46d5f0b8b70cff4#l2320 >> >> Do you know what can cause this error? > >Any chance that you're specifying the "include_unchanged_toast" option? >I briefly looked over wal2json (which isn't part of PG) and as far as I >can tell that option simply can't work correctly, and would cause >errors >like the above. > >Greetings, > >Andres Freund We were troubleshooting network, load balancing, patroni but we missed wal2json. There's even an issue on their project with our problem: https://github.com/eulerto/wal2json/issues/74 Many thanks for your insights, Julien
