Subject RE: Re[2]: [Firebird-Architect] FW: Deadlocks on FB1.5
Author Claudio Valderrama C.
Nickolay Samofatov wrote:
> 3. DPM/VIO code has a lot of places where deadlocks are possible.
> Many places in DPM rely on fixed 1 second timeouts to detect and
> process deadlocks. The problem is that deadlocks are now getting
> reported before 1 second timeout and page locking retry loop is
> looping too quickly. If I add manual 1-second timeout in those loops
> everything will work as it worked before.

But I assume this is only a temporary fix while v1.5 is released, while you
rework more code, right?

> 4. There is a bug that if locking problem happens during
> transaction-level savepoint backout during rollback engine reports
> BUGCHECK(290) instead of declaring transaction as DEAD and continue
> working.

Mark it as dead? Is it safe or is it the only alternative? If
tpb_no_auto_undo is used, you'll never encounter such case, I guess, since
there's no list of actions to undo, hence the actions inside the txn can't
be undone to mark it as committed.

BTW, what happens if tpb_no_auto_undo is specified at txn start time and
explicit requests for savepoints are made: some strange condition or the
explicit savepoints are granted and work as expected?

Claudio Valderrama C.
Consultant, SW developer. -