Re: Re: pgsql: In HS, Startup process sets SIGALRM when waiting for buffer pin.

Simon Riggs wrote:
> On Mon, 2010-01-25 at 09:52 +0200, Heikki Linnakangas wrote:
>> Would this simple scheme work:
>>
>> When the startup process has waited for a short while (ie
>> deadlock_timeout), it sends the signal "please check if you're holding a
>> pin on buffer X" to all backends. When a backend receives that signal,
>> it checks if it is holding a pin on the given buffer *and* waiting on a
>> lock. If it is, abort the transaction. Assuming that a backend can only
>> block waiting on a lock held by the startup process, deadlock detection
>> is as simple as that.
> 
> No, it won't work. A deadlock could occur after the startup process has
> already been waiting for longer than the deadlock timeout.

Retry every deadlock_timeout seconds?

--  Heikki Linnakangas EnterpriseDB   http://www.enterprisedb.com