[Pgpool-general] pgpool segfaulting and dumping core

[Tatsuo Ishii]

> On Fri, Sep 23, 2011 at 3:43 PM, Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
>>>> Ok. I think this is the cause of the problem:
>>>>
>>>>> 2011-09-21 16:23:11 LOG:   pid 23588: find_primary_node:
>>>>> pgpool_walrecrunning does not exist
>>>>
>>>> I think you did not install pgpool_walrecrunning() on DB node 2. In
>>>> this case find_primary_node() returns -1 and it is stored in
>>>>
>>>> Req_info->primary_node_id = find_primary_node();
>>>>
>>>> It is used as the parameter for TSTAE macro, which actually accesses
>>>> out of array because of -1.
>>>>
>>>> 1250                    state = TSTATE(backend,
>>>>
>>>> So the solution would be installing pgpool_walrecrunning() on DB node 2.
>>>
>>> Thanks for looking at this.  I'm admittedly rather confused.  Where is
>>> pgpool_walrerunning() documented?  I looked through the official
>>> documentation (
>>> http://pgpool.projects.postgresql.org/pgpool-II/doc/pgpool-en.html )
>>> and don't see any references.  I also checked the official tutorial (
>>> http://pgpool.projects.postgresql.org/pgpool-II/doc/tutorial-en.html )
>>> and didn't see any references.
>>
>> The documents in the URL above is for the latest stable release of
>> pgpool-II 3.1 and the version does not require installing the function
>> anymore.
>>
>> Version specific docs are coming with under doc/ directory in the
>> source code.
> 
> Ah, ok thanks.  I'm not sure how I missed this when I setup pgpool
> over a month ago.
> 
>>
>>> After googling it sounds like I need to run
>>> /usr/share/pgpool-II/sql/walrecrunning/pgpool-walrecrunning.sql
>>> against the postgres database (on the master, at which point it will
>>> automatically replicate to the standby's)?
>>> That seems to work fine:
>>> $ psql -h cuda-db2 -U postgres -d postgres -f pgpool-walrecrunning.sql
>>> CREATE FUNCTION
>>> $ psql -h cuda-db2 -U postgres -d postgres -c "select pgpool_walrecrunning();"
>>>  pgpool_walrecrunning
>>> ----------------------
>>>  f
>>> (1 row)
>>>
>>> Trying to install it on either of the standby servers fails
>>> (expectedly, since they're readonly):
>>> $ psql -h cuda-db0 -U postgres -d postgres -f pgpool-walrecrunning.sql
>>> psql:pgpool-walrecrunning.sql:4: ERROR:  cannot execute CREATE
>>> FUNCTION in a read-only transaction
>>> $ psql -h cuda-db0 -U postgres -d postgres -c "select pgpool_walrecrunning();"
>>> ERROR:  could not access file "$libdir/pgpool-walrecrunning": No such
>>> file or directory
>>>
>>> I restarted pgpool, after running the above.  Please let me know if I
>>> need to do anything else to resolve this.
>>
>> It seems cuda-db0 lacks pgpool-walrecrunning.so. Have you ever installed it?
> 
> Nope, I hadn't.  I've done that now.  Does this require a restart of
> pgpool or postgresql to take effect, or is simply installing it (with
> 'make install + running the sql script for each DB on the master)
> sufficient?

No. Just try:

$ psql -h cuda-db0 -U postgres -d postgres -c "select pgpool_walrecrunning();"

If it succeeds, you are done.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp