Only update litestream_seq if size is below WAL header size #573
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benbjohnson
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hifi
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Mar 6, 2024
| @@ -629,7 +629,7 @@ func (db *DB) acquireReadLock() error { | |||
| } | |||
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| // Execute read query to obtain read lock. | |||
| if _, err := tx.ExecContext(db.ctx, `SELECT COUNT(1) FROM _litestream_seq;`); err != nil { | |||
| if _, err := tx.ExecContext(context.Background(), `SELECT COUNT(1) FROM _litestream_seq;`); err != nil { | |||
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Why was this changed to background context? If the db context gets canceled we'd want the lock to fail fast as well, right?
hifi
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Jun 9, 2024
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With enough data, we've discovered that this commit causes a slow stream of wal overwritten by another process errors which forces new generations.
Here's a Loki grep of that string over a period of 6 hours:
The quiet gap is where I reverted this commit from our downstream fork and then the errors came back when I put the commit back. The final quiet 10 minutes is when I removed the commit again.
I don't yet know why this happens but do you have ideas @benbjohnson?
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Previously, the
litestream_seqcould increment on aPASSIVEcheckpoint even if the WAL existed and did not need to be created. This caused a loop where the increment would trigger replication. This PR fixes this by only executing the increment if the WAL is below a size threshold.Fixes #422