Subject RE: [firebird-support] Firebird hangs for a while blocking all DB operations periodically.
Author Svein Erling Tysvær
>Environment : Firebird 2.5.1 Super-Classic x64 on Windows 2008 R2 Server with 32 GB of RAM
>We have a Firebird server installation that periodically blocks all operations for a few
>minutes and then comes back alive on its own. This has happened about once a month for the
>last few months. During this blocking period, Firebird CPU usage is unusually low as this
>is a busy server. This server normally has 200-300 client attachments. The blocking time
>has varied from 2 minutes to over 10 minutes. During this time, no Firebird operations can
>be performed i.e. New connections are blocked along with existing connections. Upon
>recovery, Firebird continues processing without any other issues.
>We have noticed that this has generally occurred, but not always, during a DB sweep. Our
>sweep interval is set to 0 and we are performing the sweep once a day as a scheduled task.

Since this happen about once a month, do you happen to do massive monthly deletes or updates, Anthony, and do the blocking occur after such deletes/updates and before or during the next sweep? If so, a possible solution could (in some cases), be to delete/update a bit every hour or day rather than monthly.