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Carlos LeyvaandChris Lu
241541c026
* filer: SQL store pool defaults survive concurrent walks (idle == open == 50, lifetime 300s) The code defaults for the four SQL stores were connection_max_idle=2 with NO default for connection_max_open (unlimited) or lifetime, while the scaffold filer.toml documents 10/50/300 -- so an env-configured or minimal-toml filer got the worst possible pool. Under a concurrent listing burst (s3.lifecycle.run-shard walks 16 shards in parallel) every operation released above the 2 idle slots closes its TCP connection, so the walk opens a fresh connection per operation until the filer exhausts its ephemeral ports: list /buckets/... : failed to connect ... dial tcp ...:5432: connect: cannot assign requested address Measured on a production filer: 0 -> 28k TIME_WAIT with only ~1.3k concurrent, and in the minimal docker-compose reproduction (2000-dir bucket, port range narrowed to 400): the whole range in TIME_WAIT with only ~12 ESTABLISHED. Default all three knobs, with idle == open so released connections are kept and reused: idle connections only accumulate up to the actual peak concurrency and connection_max_lifetime_seconds recycles them, so a quiet deployment holds nothing extra. An explicit 0 still disables the caps as before. The scaffold's connection_max_idle moves 10 -> 50 to match. With this change the same reproduction completes all 16 shards with the default configuration (TIME_WAIT peak 19 vs the whole port range). * filer: trim the SQL pool default comments One line of the non-obvious why is enough; the rest narrated the code. Claude-Session: https://claude.ai/code/session_018DWwctzD4T2DmnczPRM47t * filer: leave the SQL stores' connection_max_open unset A listing holds its connection for the whole row iteration while its callback runs another query -- FilerStoreWrapper.maybeReadHardLink does a KvGet per hard-linked entry -- so every concurrent listing needs two connections from the same pool. With a default cap, listings past the cap wedge: 60 concurrent listings over hard-linked entries made no progress at all against a 50 connection pool, and the wrapper's context.WithoutCancel leaves the waiters without a deadline. The idle pool is what fixes the connection churn: idle 50 with an unbounded max_open holds the same 14 postgres sessions across a 16-way listing burst that opened 455 with idle 2. Claude-Session: https://claude.ai/code/session_018DWwctzD4T2DmnczPRM47t --------- Co-authored-by: Chris Lu <chris.lu@gmail.com>