Re: [Postgres-xc-developers] Steps to remove coordinator master

[Abbas B. <abb...@en...>]

On Mon, May 13, 2013 at 10:52 AM, Ashutosh Bapat <
ash...@en...> wrote:

> Hi Abbas,
> Why is DROP NODE executing EXEC DIRECT ON? The internal code shouldn't do
> this. EXEC DIRECT is only for debug purposes and can be deprecated in
> future. In fact, I am leaning to remove it. It's complicating matters a lot.
>

DROP NODE does not issue EXECUTE DIRECT, it tries to acquire an advisory
lock and our implementation of advisory lock uses EXEC DIRECT. Please take
a look at the function pgxc_advisory_lock. Amit can explain it more.


>
>
> On Mon, May 13, 2013 at 11:03 AM, Abbas Butt <abb...@en...>wrote:
>
>>
>>
>> On Mon, May 13, 2013 at 9:31 AM, Koichi Suzuki <koi...@gm...
>> > wrote:
>>
>>> Hello;
>>>
>>> I'm testing pgxc_ctl to remove a coordinator master.   Following your
>>> suggestions, I first stopped the coordinator master to be removed and then
>>> issued "drop node" in all the other coordinators.   Somehow drop node
>>> complains that it fails to obtain pooled connection, in fact, in drop node,
>>> "execute direct on (node_to_be_removed)" was issued.
>>>
>>> It worked fine if the removed coordinator is stopped after all the DROP
>>> NODE are successful.
>>>
>>> Did you issue CLEAN CONNECTION or pgxc_pool_reload before you issue
>>> "DROP NODE"?
>>>
>>
>> No, I did not issue any such statement. I just tested again and I am also
>> getting the following error when I issue DROP NODE
>> test=# drop node coord_2;
>> ERROR:  Failed to get pooled connections
>> CONTEXT:  SQL statement "EXECUTE DIRECT ON (coord_2) 'SELECT
>> pg_catalog.pg_try_advisory_xact_lock_shared(65535, 0)'"
>> test=#
>>
>> This is a bug and has to be fixed. The bug is that DROP NODE should not
>> be trying to acquire the lock. I will send a fix for this today. The steps
>> remain the same as before.
>>
>>
>>
>>>
>>> Regards;
>>> ----------
>>> Koichi Suzuki
>>>
>>
>>
>>
>> --
>> --
>> *Abbas*
>>  Architect
>>
>> Ph: 92.334.5100153
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>>
>
>
> --
> Best Wishes,
> Ashutosh Bapat
> EntepriseDB Corporation
> The Postgres Database Company
>



-- 
-- 
*Abbas*
 Architect

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 Skype ID: gabbasb
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*
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