fix(walrestore): serve pg_rewind without prefetching and flag machinery#1007
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fix(walrestore): serve pg_rewind without prefetching and flag machinery#1007armru wants to merge 2 commits into
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The operator now tells WAL restore plugins when a restore request is made on behalf of pg_rewind (cloudnative-pg/cnpg-i#351). pg_rewind walks the timeline backwards, fetches every WAL file it needs exactly once, and treats any restore failure as fatal, so both optimizations meant for an instance in recovery must stay off: prefetching the following segments is wasted work that ends in an archive miss, and the end-of-wal-stream flag recorded by such a miss makes a later invocation fail on a segment that is available in the archive, aborting the whole rewind. The cnpg-i dependency points to a pseudo-version of that pull request and will be moved to the next tagged release once it is available. Ref: cloudnative-pg/cloudnative-pg#11200 Signed-off-by: Armando Ruocco <armando.ruocco@enterprisedb.com>
…machinery Signed-off-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>
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When a demoted primary rejoins the cluster after a failover, the instance manager runs
pg_rewind --restore-target-wal, and the resultingrestore_commandinvocations 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.