Re: assertion failure 9.3.4

On 04/17/2014 10:15 AM, Andrew Dunstan wrote:
>
> On 04/16/2014 10:28 PM, Tom Lane wrote:
>> Andrew Dunstan <andrew@dunslane.net> writes:
>>> On 04/16/2014 07:19 PM, Tom Lane wrote:
>>>> Yeah, it would be real nice to see a self-contained test case for 
>>>> this.
>>> Well, that might be hard to put together, but I did try running without
>>> pg_stat_statements and auto_explain loaded and the error did not occur.
>>> Not sure where that gets us in terms of deciding on a culprit.
>> Could we at least see the exact parameter settings for 
>> pg_stat_statements
>> and auto_explain?  (And any other GUCs with nondefault values?)
>>
>>
>
>
> Here are all the settings from the run that failed:
>
>    listen_addresses = '*'
>    port = 5432
>    fsync = on
>    synchronous_commit = off
>    checkpoint_segments = 128
>    checkpoint_completion_target = 0.9
>    shared_buffers = 512MB
>    max_connections = 300
>    work_mem = 128MB
>    maintenance_work_mem = 32MB
>    effective_cache_size = 16GB
>    effective_io_concurrency = 2
>    logging_collector = on
>    log_destination = 'stderr'
>    log_filename = 'postgresql-%a.log'
>    log_rotation_size = 0
>    log_truncate_on_rotation = on
>    log_line_prefix = '%t [%p] %l: '
>    log_connections = on
>    log_disconnections = on
>    log_statement = 'all'
>    track_activity_query_size = 10240
>    shared_preload_libraries = 'auto_explain,pg_stat_statements'
>
> As you can see, auto_explain's log_min_duration hasn't been set, so it 
> shouldn't be doing anything very much, I should think.



There definitely seems to be something going on involving these two 
pre-loaded modules. With both auto_explain and pg_stat_statements 
preloaded I can reproduce the error fairly reliably. I have also 
reproduced it, but less reliably, with auto_explain alone loaded. I have 
not reproduced it with pg_stat_statements alone loaded, but Josh Berkus 
has reported that another client has experienced something very similar 
(duplicate PK errors on a non-assertion-enabled build) with 
pg_stat_statements alone loaded.

cheers

andrew