[pgpool-general: 5009] Re: Avoiding downtime when pgpool changes require a restart

[Jacobo García López de Araujo]

Hello Muhammad,

The problem was actually caused by building pgpool by pointing to this
specific commit. I built a new version with the code in V3_5_STABLE branch
and I'm not observing problems so far.

Thanks again for your time.

On Wed, Sep 21, 2016 at 5:34 PM Muhammad Usama <m.usama at gmail.com> wrote:

> Hi
>
> Can you please provide little more information about what OS you are using
> and how to reproduce the problem. As I have configured and build pgpool
> with the exact options you mentioned and I am not getting any error.
>
> Did you get stack smashing... message as soon as you start the pgpool-II
> or executing some command produce that error?
>
> Thanks
> Best regards
> Muhammad Usama
>
>
>
>
> On Wed, Sep 21, 2016 at 7:27 PM, Jacobo García López de Araujo <
> jacobo.garcia at gmail.com> wrote:
>
>> Hello,
>>
>> I compiled a PgPool based on a git clone pointing to the particular
>> commit with the fix of the issue I raised. I deployed the new version and I
>> got the following error when trying to start PgPool
>>
>> Sep 21 14:16:37 srv0.net pgpool: *** stack smashing detected ***:
>> /usr/sbin/pgpool terminated
>>
>> These are my build dependencies:
>> 'libpam0g-dev', 'libssl-dev', 'libmemcached-dev', 'libpq-dev',
>> 'libpam0g-dev', 'libmemcached-dev'
>>
>> These are my build options:
>> configure \
>>       '--disable-rpath',
>>       '--with-openssl',
>>       '--with-pam',
>>       '--with-memcached=/usr/include/libmemcached'
>>
>>       prefix: '/usr',
>>       bindir: '/usr/sbin',
>>       includedir: '/usr/include/pgpool2',
>>       sysconfdir: '/etc/pgpool2'
>>
>> It seems there is a bug on the fix.
>>
>> Many thanks for your time.
>>
>> J.
>>
>>
>>
>>
>> On Mon, Sep 19, 2016 at 10:57 PM Jacobo García López de Araujo <
>> jacobo.garcia at gmail.com> wrote:
>>
>>> Muhammad, many thanks for your patch, I'll deploy a new PgPool build
>>> with this patch and I'll write down here the results of my tests.
>>>
>>> As stated above, thanks.
>>>
>>>
>>> On Mon, Sep 19, 2016 at 10:38 PM Muhammad Usama <m.usama at gmail.com>
>>> wrote:
>>>
>>>> On Thu, Sep 15, 2016 at 9:43 PM, Jacobo García López de Araujo <
>>>> jacobo.garcia at gmail.com> wrote:
>>>>
>>>>> I believe this is currently a bug, I'd like to know better before I
>>>>> fill a bug against PgPool bug tracker, I'm afraid that I'm missing
>>>>> something, but after one more day of tests, I have been unsuccessful of
>>>>> restarting 2 PgPpool watchdog without incurring in a few seconds of
>>>>> downtime.
>>>>>
>>>>> I'll be grateful for any help or information about this issue.
>>>>>
>>>>> Many thanks,
>>>>>
>>>>> Jacobo García.
>>>>>
>>>>>
>>>>>
>>>> Hi
>>>>
>>>> Your use case is valid and pgpool-II should not produce a FATAL error
>>>> if the configurations of nodes differs. I have pushed the fix for that
>>>> in pgpool-II 3.5 and master branches, You can try building from the source
>>>> code to check if your problem is fixed
>>>>
>>>>
>>>> https://git.postgresql.org/gitweb/?p=pgpool2.git;a=commitdiff;h=a38fa0910f94dfc5314fe34bd8ad86dc7dfb594e
>>>>
>>>> Thanks
>>>> Best regards
>>>> Muhammad Usama
>>>>
>>>>>
>>>>>
>>>>> On Wed, Sep 14, 2016 at 4:12 PM Jacobo García López de Araujo <
>>>>> jacobo.garcia at gmail.com> wrote:
>>>>>
>>>>>> Hello,
>>>>>>
>>>>>> I am trying to set load_balance_mode =  off setting in one testing 2
>>>>>> nodes cluster. The option is currently set to on. It is a setting
>>>>>> that requires a full restart in order to be changed.
>>>>>>
>>>>>> I haven't found a solution that does not provoke downtime on my setup.
>>>>>>
>>>>>> If I restart pgpool on the master node the watchdog is failed over
>>>>>> to the secondary, then master will refuse to join the cluster with
>>>>>> pgpool logs spitting the following error:
>>>>>>
>>>>>> FATAL:  configuration error. The configurations on master node is
>>>>>> different
>>>>>>
>>>>>> Then the master will shut down, every time I start the now old master
>>>>>> it will refuse to join the cluster because settings are different.
>>>>>> In this situation I just have one node running pgpool so if I
>>>>>> restart this node it will stop accepting connections through the
>>>>>> virtual IP and downtime will occur.
>>>>>>
>>>>>> The other strategy I tried is restart pgpool on the secondary node
>>>>>> first. In this case I also got the same error, and the secondary node
>>>>>> refuses to join the cluster too.
>>>>>>
>>>>>> I'd like to know what is the ideal procedure in order to change one
>>>>>> of those settings without having downtime.
>>>>>>
>>>>>> Many thanks for your time.
>>>>>>
>>>>>> Jacobo García.
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Jacobo García López de Araujo.
>>>>>>
>>>>> --
>>>>> Jacobo García López de Araujo.
>>>>>
>>>>> _______________________________________________
>>>>> pgpool-general mailing list
>>>>> pgpool-general at pgpool.net
>>>>> http://www.pgpool.net/mailman/listinfo/pgpool-general
>>>>>
>>>>>
>>>> --
>>> Jacobo García López de Araujo.
>>>
>> --
>> Jacobo García López de Araujo.
>>
>
> --
Jacobo García López de Araujo.
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