Re: PostgresSQL 9.5 and systemd autorestart but without replication.

Pid 1449 is postgres: startup process recovering 00000001000000010000002C

strace -p 1449 -e write

gives

Process 1449 attached

SIGUSR1 {si_signo=SIGUSR1, si_code=SI_USER, si_pid=1488, si_uid=26} ---
write(12, "\0", 1)

Does this mean that write is denied on the master?

TIA

Poul

2016-10-24 14:26 GMT+02:00 Poul Kristensen <bcc5226(at)gmail(dot)com>:

> This is output from strace -p 1449(pid):
>
> The strace keeps repeating this :
>
>
> read(7, 0x7fff0dc197f7, 1) = -1 EAGAIN (Resource temporarily
> unavailable)
> epoll_create(3) = 36
> epoll_ctl(36, EPOLL_CTL_ADD, 11, {EPOLLIN|EPOLLERR|EPOLLHUP,
> {u32=18051624, u64=18051624}}) = 0
> epoll_ctl(36, EPOLL_CTL_ADD, 7, {EPOLLIN|EPOLLERR|EPOLLHUP, {u32=18051648,
> u64=18051648}}) = 0
> epoll_wait(36, {}, 1, 5000) = 0
> close(36) = 0
>
> Does anyone have an idea off want is going on.
>
> TIA.
>
> Poul
>
>
> 2016-10-24 11:59 GMT+02:00 Poul Kristensen <bcc5226(at)gmail(dot)com>:
>
>>
>> I am now running PostgreSQL 9.6 master/replica:
>>
>> Master - Wal sender process OK!
>>
>> Standby: Started the server is succesfully but is recovering for several
>> days and the standby database is not accessible!
>> Wal receiver streaming is running and is in sync master.
>>
>>
>>
>> select * from pg_locks p1 left join pg_stat_activity psa on
>> p1.pid=psa.pid;
>> -[ RECORD 9 ]------+----------------------------------------------------
>> ------------------------
>> locktype | relation
>> database | 0
>> relation | 2671
>> page |
>> tuple |
>> virtualxid |
>> transactionid |
>> classid |
>> objid |
>> objsubid |
>> virtualtransaction | 3/86715
>> pid | 29001
>> mode | AccessShareLock
>> granted | t
>> fastpath | f
>> datid | 13322
>> datname | postgres
>> pid | 29001
>> usesysid | 10
>> usename | postgres
>> application_name | psql
>> client_addr |
>> client_hostname |
>> client_port | -1
>> backend_start | 2016-10-24 11:41:20.291612+02
>> xact_start | 2016-10-24 11:53:57.815105+02
>> query_start | 2016-10-24 11:53:57.815105+02
>> state_change | 2016-10-24 11:53:57.815111+02
>> wait_event_type |
>> wait_event |
>> state | active
>> backend_xid |
>> backend_xmin | 2312
>>
>> I can not figure it out!
>>
>> OS:rhel 7.2
>>
>> Thanks
>>
>> Poul
>>
>>
>>
>>
>>
>> 2016-10-17 20:35 GMT+02:00 Poul Kristensen <bcc5226(at)gmail(dot)com>:
>>
>>> RHEL 7.2, which made the postgresql-9.5.service restart on both virtual
>>> servers because of some network problem I am almost sure.
>>>
>>> The problem now is to make the replication server understand that he is
>>> not the master now until next failover. If I can not do this by
>>> reestablishing
>>> recovery.conf and then restarting the postgresql.-9.5.service then I am
>>> running out of ideas. I have to make sure to be able to handle the
>>> failover's and the reestablishment of the "replica" or standby server
>>> again when going in production on the physical servers.
>>>
>>> Thanks
>>> Poul
>>>
>>>
>>>
>>> 2016-10-14 14:53 GMT+02:00 Scott Mead <scottm(at)openscg(dot)com>:
>>>
>>>> On Fri, Oct 14, 2016 at 7:42 AM, Poul Kristensen <bcc5226(at)gmail(dot)com>
>>>> wrote:
>>>>
>>>>> Hi !
>>>>>
>>>>> Hopefully this is a situation in virtuel environments and not on
>>>>> physical
>>>>> servers with storage on SAN.as replication have to follow up in a
>>>>> autorestart without a manual new basebackup.
>>>>>
>>>>
>>>> What OS are you running? recovery.conf gets renamed to 'recovery.done'
>>>> only when a promotion (failover) occurs. This can happen a number of ways (*pg_ctl
>>>> promote, trigger_file, etc..). *Typically, these commands are not
>>>> executed automatically for you, you would have had to either install a tool
>>>> that does auto failover, *or* the startup scripts in your OS did
>>>> something (highly doubtful).
>>>>
>>>> --Scott
>>>>
>>>>
>>>>
>>>>> Does anyone have experience with replication on physical
>>>>> servers(slaves)?
>>>>>
>>>>>
>>>> Thanks
>>>>>
>>>>> Poul
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> 2016-10-13 17:45 GMT+02:00 Poul Kristensen <bcc5226(at)gmail(dot)com>:
>>>>>
>>>>>> Thank you for fast respons.
>>>>>>
>>>>>> No. The recovery.conf has now replace a recovery.done file on the
>>>>>> slave.
>>>>>> No errors in the pg_log. I have not earlier experienced this
>>>>>> situation.
>>>>>> The feature of autorestart is really nice.
>>>>>> BTW: I do not quite understand why the recovery.conf are replaced
>>>>>> with a recovery.done file.
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>> /Poul
>>>>>>
>>>>>>
>>>>>> 2016-10-13 16:30 GMT+02:00 Hunley, Douglas <
>>>>>> douglas(dot)hunley(at)openscg(dot)com>:
>>>>>>
>>>>>>>
>>>>>>> On Thu, Oct 13, 2016 at 6:00 AM, Poul Kristensen <bcc5226(at)gmail(dot)com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> This morning I noticed that my 2 PG virtual servers had made an
>>>>>>>> automatic
>>>>>>>> restart at exactly the same time 00:00. The 2 servers is running
>>>>>>>> and accepting connections but no WALL sender and no WALL receicver is
>>>>>>>> running.
>>>>>>>> Why don't replication follow up!
>>>>>>>> Do I have to make a new pg_basebackup from primarily to replica?
>>>>>>>> OS: RHEL 7.2
>>>>>>>>
>>>>>>>
>>>>>>> Is the recovery.conf file still present and valid in $PGDATA on the
>>>>>>> slave? Any errors in the slave's pg_log directory concerning the
>>>>>>> replication?
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> {
>>>>>>> "name" : "douglas j hunley",
>>>>>>> "email" : "douglas(dot)hunley(at)openscg(dot)com <doug(dot)hunley(at)gmail(dot)com>",
>>>>>>> "title" : "database engineer",
>>>>>>> "phone" : "+1 732 339 3419 x163"
>>>>>>> }
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Med venlig hilsen / Best regards
>>>>>> Poul Kristensen
>>>>>> Linux-OS/Virtualizationexpert and Oracle DBA
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Med venlig hilsen / Best regards
>>>>> Poul Kristensen
>>>>> Linux-OS/Virtualizationexpert and Oracle DBA
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> --
>>>> Scott Mead
>>>> Sr. Architect
>>>> *OpenSCG <http://openscg.com>*
>>>> http://openscg.com
>>>>
>>>
>>>
>>>
>>> --
>>> Med venlig hilsen / Best regards
>>> Poul Kristensen
>>> Linux-OS/Virtualizationexpert and Oracle DBA
>>>
>>
>>
>>
>> --
>> Med venlig hilsen / Best regards
>> Poul Kristensen
>> Linux-OS/Virtualizationexpert and Oracle DBA
>>
>
>
>
> --
> Med venlig hilsen / Best regards
> Poul Kristensen
> Linux-OS/Virtualizationexpert and Oracle DBA
>

--
Med venlig hilsen / Best regards
Poul Kristensen
Linux-OS/Virtualizationexpert and Oracle DBA