[pgpool-general: 5637] Re: pgpool 3.6.4 failover - failover scenario question

[Muhammad Usama]

On Wed, Jul 19, 2017 at 12:07 AM, Shay Cohavi <cohavisi at gmail.com> wrote:

> Hi,
> setting "health_check_timeout = 0" has fixed the problem. but why it is
> set to "20" by default?
>

Basically you are hitting some bug in the health check thats why the
default value of 20 is causing the problem with your setup. In the normal
scenario it should work fine.
We are looking into the cause and fix for the health_check_timeout issue.

Thanks
Best Regards
Muhammad Usama

>
>
> Thanks,
> cohavisi
>
> On Mon, Jul 17, 2017 at 7:29 PM, Muhammad Usama <m.usama at gmail.com> wrote:
>
>>
>>
>> On Mon, Jul 17, 2017 at 8:27 PM, Shay Cohavi <cohavisi at gmail.com> wrote:
>>
>>> Hi,
>>>
>>> scenario
>>> server1 - master pgpool + primary postgres
>>> server2 - slave pgpool + secondary postgres.
>>>
>>> 1. server1 (master pgpool + primary postgres) is being poweroff.
>>> 2. server2 is being successfully escalating to the master Pgpool-II.
>>> postgres failover is being triggered (secondary pgpool has been promoted)
>>> !!!! pgpool keeps searching for the primary node!!
>>>
>>>
>>> pgpool log attached...
>>>
>>
>> As per the logs, Pgpool-II is correctly preforming all the required steps
>> when the it looses the server1, i.e The standby Pgpool-II is successfully
>> promoted to new master Pgpool-II and also the new master Pgpool-II is
>> triggering the failover on the PostgreSQL node (192.168.15.55:5432) that
>> was located on server1,
>> The problem is that after the failover was performed and failover_command
>> was executed by Pgpool-II, The PostgreSQL server
>> 192.168.15.56:5432 becomes unreachable, and Pgpool-II keep looking for
>> primary node, which it is not able to connect to.
>>
>> Do you get any message on 192.168.15.56:5432 PostgreSQL server, as why
>> it does not accepts the connection.
>>
>> Also can you perform the same test by disabling the health check timeout
>> (set health_check_timeout = 0),
>>
>> Thanks
>> Best Regards
>> Muhammad Usama
>>
>>>
>>> Thanks,
>>> cohavisi
>>>
>>> On Mon, Jul 17, 2017 at 2:27 PM, Muhammad Usama <m.usama at gmail.com>
>>> wrote:
>>>
>>>> Hi,
>>>>
>>>> There doesn't seems to be anything wrong with the configuration or
>>>> cluster design, And if the secondary Pgpool-II is successfully escalating
>>>> to the master Pgpool-II and acquiring the VIP, It should also perform the
>>>> backend node failover without any problem.
>>>>
>>>> Can you please elaborate the situation what actually is the behaviour
>>>> of Pgpool-II after the server1 failure.
>>>>
>>>> 1- Does Pgpool-II (on server 2) performs the backend failover but it
>>>> does not promotes the standby PostgreSQL to primary?
>>>> 2 - Or is it the case where Pgpool-II never performs the failover.
>>>>
>>>> Also It would be really helpful if you can share the pgpool log file
>>>> when this situation occurs.
>>>>
>>>> Thanks
>>>> Best regards
>>>> Muhammad Usama
>>>>
>>>> On Fri, Jul 14, 2017 at 9:56 PM, Shay Cohavi <cohavisi at gmail.com>
>>>> wrote:
>>>>
>>>>> Hi,
>>>>> I have 2 postgres servers (postgres 9.3.5) installed with
>>>>> pgpool(3.6.4) on the same node.
>>>>>
>>>>>
>>>>> server1 192.168.15.55
>>>>> server 2 192.168.15.56
>>>>> pgpool vip 192.168.15.59
>>>>>
>>>>>
>>>>>
>>>>> ​
>>>>>
>>>>>
>>>>> # psql -U postgres -h 192.168.15.59 -p 9999 -c 'show pool_nodes'
>>>>>  node_id |   hostname    | port | status | lb_weight |  role   |
>>>>> select_cnt | load_balance_node | replication_delay
>>>>> ---------+---------------+------+--------+-----------+------
>>>>> ---+------------+-------------------+-------------------
>>>>>  0       | 192.168.15.55 | 5432 | up     | 0.500000  | primary | 3718
>>>>>       | true              | 0
>>>>>  1       | 192.168.15.56 | 5432 | up     | 0.500000  | standby | 0
>>>>>      | false             | 0
>>>>>
>>>>>
>>>>>
>>>>> my question is about disaster recovery scenario:
>>>>>
>>>>> 1. *"primary postgres" and the "master pgpool" is on server1* .
>>>>> pgpool vip established on this node (192.168.15.59)
>>>>>
>>>>> 2. server1 went down due to  power break. (server1 is dead!!!)
>>>>>
>>>>> 3. pgpool on server server2 get promoted (vip established
>>>>> 192.168.15.59) .
>>>>>
>>>>> 4. NO postgres failover action occurs by the pgpool. pgpool keeps
>>>>> searching for primary postgres with no success.
>>>>>
>>>>> should the new master pgpool execute an failover action(promote) to
>>>>> the slave postgres ??
>>>>>
>>>>>
>>>>>
>>>>> Thanks,
>>>>> cohavisi
>>>>>
>>>>> _______________________________________________
>>>>> pgpool-general mailing list
>>>>> pgpool-general at pgpool.net
>>>>> http://www.pgpool.net/mailman/listinfo/pgpool-general
>>>>>
>>>>>
>>>>
>>>
>>
>
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