fix: wal archive - early return if WAL was in spool #57
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…tware#45) Optimizes the WALServiceImplementation. Archive method by introducing a local spool-based check to prevent redundant WAL uploads. This is particularly relevant when maxParallel is set to a value greater than 1. Signed-off-by: Piotr Szyma <thompson2908@gmail.com>
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Agalin
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Jan 8, 2026
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Summary
This PR optimizes the
WALServiceImplementation.Archivemethod by introducing a local spool-based check to prevent redundant WAL uploads. This is particularly relevant when maxParallel is set to a value greater than 1.Similar to how its implemented in
plugin-barman-cloud: https://github.com/cloudnative-pg/plugin-barman-cloud/blob/b7b2b5b78755d4fcd7242100cd79df3095b58174/internal/cnpgi/common/wal.go#L177The Problem
When
maxParallel> 1, pgBackRest attempts to archive the requested WAL segment plus the next N−1 segments speculatively. However, PostgreSQL issues WALArchiveRequest calls sequentially (WAL 1, then WAL 2, then WAL 3).Under the previous implementation, this created a "sliding window" of redundant work:
This resulted in unnecessary network overhead and frequent warnings in the logs regarding files already existing in the repository with the same checksum.
Changes
Added a check against the spool in
WALServiceImplementation.Archive. If a WAL segment is already marked as completed in the local spool, the plugin returns a success response immediately without invoking the pgBackRest binary.