Re: [COMMITTERS] pgsql: Rearm statement_timeout after each executed query.

[Andres Freund]

On 2018-02-09 15:50:44 -0500, Robert Haas wrote:
> On Wed, Feb 7, 2018 at 7:04 PM, Thomas Munro
>  wrote:
> > On Tue, Feb 6, 2018 at 5:21 PM, Peter Eisentraut
> >  wrote:
> >> On 9/18/17 22:41, Andres Freund wrote:
> >>> Rearm statement_timeout after each executed query.
> >>
> >> This appears to have broken statement_timeout behavior in master such
> >> that only every second query is affected by it.
> >
> > Yeah, I also just ran into this while testing a nearby complaint about
> > statement timeouts vs parallel query.  In the error path
> > stmt_timeout_active remains true, so the next statement does nothing
> > in enable_statement_timeout().  I think we just need to clear that
> > flag in the error path, right where we call disable_all_timeouts().
> > See attached.
> 
> Looks right.  Committed, but I thought the comment was strange (forget
> about?) so I just left that out.

Thanks Peter, Thomas, Robert!

- Andres

Re: [COMMITTERS] pgsql: Rearm statement_timeout after each executed query.

[Robert Haas]

On Wed, Feb 7, 2018 at 7:04 PM, Thomas Munro
 wrote:
> On Tue, Feb 6, 2018 at 5:21 PM, Peter Eisentraut
>  wrote:
>> On 9/18/17 22:41, Andres Freund wrote:
>>> Rearm statement_timeout after each executed query.
>>
>> This appears to have broken statement_timeout behavior in master such
>> that only every second query is affected by it.
>
> Yeah, I also just ran into this while testing a nearby complaint about
> statement timeouts vs parallel query.  In the error path
> stmt_timeout_active remains true, so the next statement does nothing
> in enable_statement_timeout().  I think we just need to clear that
> flag in the error path, right where we call disable_all_timeouts().
> See attached.

Looks right.  Committed, but I thought the comment was strange (forget
about?) so I just left that out.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Re: [COMMITTERS] pgsql: Rearm statement_timeout after each executed query.

[Thomas Munro]

On Tue, Feb 6, 2018 at 5:21 PM, Peter Eisentraut
 wrote:
> On 9/18/17 22:41, Andres Freund wrote:
>> Rearm statement_timeout after each executed query.
>
> This appears to have broken statement_timeout behavior in master such
> that only every second query is affected by it.

Yeah, I also just ran into this while testing a nearby complaint about
statement timeouts vs parallel query.  In the error path
stmt_timeout_active remains true, so the next statement does nothing
in enable_statement_timeout().  I think we just need to clear that
flag in the error path, right where we call disable_all_timeouts().
See attached.

-- 
Thomas Munro
http://www.enterprisedb.com


fix-statement-timeout.patch
Description: Binary data

Re: [COMMITTERS] pgsql: Rearm statement_timeout after each executed query.

[Peter Eisentraut]

On 9/18/17 22:41, Andres Freund wrote:
> Rearm statement_timeout after each executed query.

This appears to have broken statement_timeout behavior in master such
that only every second query is affected by it.  For example:

create table t1 as select * from generate_series(0, 1) as _(a);
set statement_timeout = '1s';
explain analyze select from t1 where a = 55;  -- gets canceled
explain analyze select from t1 where a = 55;  -- completes (>1s)
explain analyze select from t1 where a = 55;  -- gets canceled
explain analyze select from t1 where a = 55;  -- completes (>1s)
etc.

-- 
Peter Eisentraut  http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services