* filer: give the SQL stores' key-value reads their own connections
A listing holds the connection its rows are on for the whole iteration, and
FilerStoreWrapper calls maybeReadHardLink -> KvGet from inside that iteration,
so a hard-linked entry needs a second connection while the first is still busy.
Out of one bounded pool that is a deadlock: the listings fill the pool and then
wait for a connection none of them will release, and the wrapper's
context.WithoutCancel leaves the waiters without a deadline, so the filer stays
wedged rather than erroring.
The sqlite store shows it at its sharpest -- it allows a single connection, so
one listing over one hard-linked entry never returns. On postgres with
connection_max_open = 50, 60 concurrent listings over hard-linked entries made
no progress at all.
Key-value reads now run on their own pool, carved out of connection_max_open
rather than added to it, so the operator's cap still bounds what the store opens
against the database. An unbounded pool keeps a single pool: nothing can wait
there. sqlite's single connection becomes two, one per pool, and its writes get
a busy timeout so a write that meets the reader waits instead of failing.
Claude-Session: https://claude.ai/code/session_018DWwctzD4T2DmnczPRM47t
* sqlite: keep both pools on one database, whatever the dbFile spells
A dbFile that already carries URI options got a second "?" appended, which the
driver reads as part of the preceding option value, and a bare :memory: is
private to each connection, so the key-value pool would open its own empty
database and every key-value operation would fail on a missing filemeta.
Claude-Session: https://claude.ai/code/session_018DWwctzD4T2DmnczPRM47t
* sqlite: assert the busy timeout on the in-memory DSN too
Claude-Session: https://claude.ai/code/session_018DWwctzD4T2DmnczPRM47t
Concurrent bucket deletion across multiple filer replicas races on the
per-bucket DROP TABLE. The first replica drops the table; the rest hit
an undefined-table error (postgres 42P01, mysql 1051) which propagates
out of DeleteFolderChildren and panics the filer. On restart the same
pending DROP re-runs and the filer crash-loops.
Make the drop idempotent. Same defect class in all SQL backends, so fix
postgres, postgres2, mysql, mysql2, and sqlite together.
Chris Lu