When a demoted primary rejoins the cluster after a failover, the
instance manager runs `pg_rewind --restore-target-wal`, and the
resulting `restore_command` invocations are served by this sidecar
exactly as if an instance in recovery were asking. pg_rewind walks the
timeline backwards, fetches every WAL file it needs exactly once, and
treats any restore failure as fatal, so two optimizations meant for
recovery break it: prefetching the following segments is wasted work
that, past the end of the timeline, is guaranteed to end in an archive
miss, and the end-of-wal-stream flag recorded by that miss makes a later
invocation fail without contacting the object store, on a segment the
archive actually has, aborting the whole rewind.
The restore request now carries the context it is made in
(cloudnative-pg/cnpg-i#351). When it says `MODE_REWIND`, the sidecar
restores exactly the requested file: no prefetching, no
end-of-wal-stream flag check, no flag recording. Requests from operators
predating the field keep the current behavior.
This is the plugin-side counterpart of
cloudnative-pg/cloudnative-pg#11204. The cnpg-i dependency points to a
pseudo-version of the protocol pull request and will move to the next
tagged release once it is available.
Signed-off-by: Armando Ruocco <armando.ruocco@enterprisedb.com>
Signed-off-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>
Co-authored-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>
During a replica cluster failover, the designated primary could
incorrectly attempt to restore WALs from its own object store instead of
the replica source, causing recovery to fail. This happened because the
previous logic relied on IsReplica() returning true, but that flag can
already be false while PostgreSQL is still in recovery and needs WALs
from the source cluster.
Signed-off-by: Leonardo Cecchi <leonardo.cecchi@enterprisedb.com>
Signed-off-by: Armando Ruocco <armando.ruocco@enterprisedb.com>
Signed-off-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>
Co-authored-by: Armando Ruocco <armando.ruocco@enterprisedb.com>
