[Pdns-users] SQLite3 problem during stress

[bert hubert]

On Mon, Jul 20, 2009 at 11:01 AM, Christian Svensson<blue at cmd.nu> wrote:
> Yes, updating only one zone at the time is very much acceptable - that the
> initial transfer takes quite long time does not matter.
>
> We do not want to use an "active" database due to memory / CPU footprint. If
> PowerDNS locks the table and let the other threads just wait for the lock
> like any other mutex it would probably be just fine with distributor-threads
> = 1.
>
> I want to note that indeed PowerDNS _crashes_ / _exits_ in the end due to
> the "Database is locked" error. Since I'm currently testing with OpenDBX I
> don't know íf this is something that is regarded as an OpenDBX or PowerDNS
> bug - but gsqlite3 did also crash during heavy load which (as stated before)
> makes me believe that it's backend agnostic.

PowerDNS does not crash under heavy load normally. Even with
distributor-threads=1, you may get multiple active backends. This may
explain the locking issues. Perhaps Norbert is right that our sqlite3
code needs to deal better with timeouts.

I currently have the entire .NET zone (28 million records) loaded in
sqlite3 and will stresstest it later this week.

Will let you know.

     Bert