[pgpool-general: 1450] Re: pgPool Online Recovery Streaming Replication
Tatsuo Ishii
ishii at postgresql.org
Fri Mar 1 14:38:49 JST 2013
> Hi Tatsuo,
> I reproduce the problem on pgpool 3.2.3.
> Basically server1 is the originally primary, and server0 is standby. When
> server1 kernel panic, server0 failover which become the primary, which is
> expected.
> When failed server1 comes back online, execute pcp_recovery on server0 to
> recover and connect it to primary as a standby, which is expected also.
> Now, if server0 kernel panic, pgpool on server1 trigger the failover
> script, however, the script did not really get executed although it is
> logged in the pgpool log.
How do you determine failover scrit did not get executed?
I see this line:
Feb 28 21:47:41 server1 pgpool[2054]: execute command:
/home/pgpool/failover.py -d 0 -h server0 -p 5432 -D /opt/postgres/9.2/data
-m 1 -H server1 -M 0 -P 0 -r 5432 -R /opt/postgres/9.2/data
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp
> See below for the trace:
>
> Feb 28 21:47:40 server1 pgpool[3593]: connect_inet_domain_socket: select()
> timedout. retrying...
> Feb 28 21:47:40 server1 pgpool[3679]: connect_inet_domain_socket: select()
> timedout. retrying...
> Feb 28 21:47:41 server1 pgpool[3594]: wd_create_send_socket: connect()
> reports failure (No route to host). You can safely ignore this while
> starting up.
> Feb 28 21:47:41 server1 pgpool[2054]: pool_flush_it: write failed to
> backend (0). reason: No route to host offset: 0 wlen: 42
> Feb 28 21:47:41 server1 pgpool[2054]: notice_backend_error: called from
> pgpool main. ignored.
> Feb 28 21:47:41 server1 pgpool[2054]: child_exit: called from pgpool main.
> ignored.
> Feb 28 21:47:41 server1 pgpool[2054]: pool_read: EOF encountered with
> backend
> Feb 28 21:47:41 server1 pgpool[2054]: s_do_auth: error while reading
> message kind
> Feb 28 21:47:41 server1 pgpool[2054]: make_persistent_db_connection:
> s_do_auth failed
> Feb 28 21:47:41 server1 pgpool[2054]: health check failed. 0 th host
> server0 at port 5432 is down
> Feb 28 21:47:41 server1 pgpool[2054]: health check retry sleep time: 5
> second(s)
> Feb 28 21:47:41 server1 pgpool[2054]: starting degeneration. shutdown host
> server0(5432)
> Feb 28 21:47:41 server1 pgpool[2054]: Restart all children
> Feb 28 21:47:41 server1 pgpool[2054]: execute command:
> /home/pgpool/failover.py -d 0 -h server0 -p 5432 -D /opt/postgres/9.2/data
> -m 1 -H server1 -M 0 -P 0 -r 5432 -R /opt/postgres/9.2/data
> Feb 28 21:47:41 server1 pgpool[2054]: find_primary_node_repeatedly: waiting
> for finding a primary node
> Feb 28 21:47:41 server1 pgpool[2054]: connect_inet_domain_socket_by_port:
> health check timer expired
> Feb 28 21:47:41 server1 pgpool[2054]: make_persistent_db_connection:
> connection to server1(5432) failed
> Feb 28 21:47:41 server1 pgpool[2054]: find_primary_node:
> make_persistent_connection failed
> Feb 28 21:47:41 server1 pgpool[3679]: connect_inet_domain_socket: select()
> timedout. retrying...
> Feb 28 21:47:42 server1 pgpool[2054]: connect_inet_domain_socket_by_port:
> health check timer expired
>
> above logs repeat few times, and after few seconds, i see this:
> Feb 28 21:47:47 server1 pgpool[3679]: check_replication_time_lag: could not
> connect to DB node 0, check sr_check_user and sr_check_password
>
> Feb 28 21:48:24 server1 pgpool[2054]: find_primary_node:
> make_persistent_connection failed
> Feb 28 21:48:25 server1 pgpool[3679]: connect_inet_domain_socket: select()
> timedout. retrying...
> Feb 28 21:48:25 server1 pgpool[2057]: wd_lifecheck: lifecheck failed 3
> times. pgpool 0 (server1:9999) seems not to be working
> Feb 28 21:48:25 server1 pgpool[3679]: connect_inet_domain_socket:
> getsockopt() detected error: No route to host
> Feb 28 21:48:25 server1 pgpool[3679]: make_persistent_db_connection:
> connection to server0(5432) failed
> Feb 28 21:48:25 server1 pgpool[2057]: wd_lifecheck: lifecheck failed 3
> times. pgpool 1 (server0:9999) seems not to be working
> Feb 28 21:48:25 server1 pgpool[2057]: wd_lifecheck: watchdog status is
> DOWN. You need to restart this for recovery.
> Feb 28 21:48:25 server1 pgpool[3679]: check_replication_time_lag: could not
> connect to DB node 0, check sr_check_user and sr_check_password
>
> Feb 28 21:48:44 server1 pgpool[2057]: wd_lifecheck: lifecheck failed 3
> times. pgpool 0 (server1:9999) seems not to be working
> Feb 28 21:48:44 server1 pgpool[2057]: wd_lifecheck: lifecheck failed 3
> times. pgpool 1 (server0:9999) seems not to be working
>
> Feb 28 21:49:10 server1 pgpool[2054]: connect_inet_domain_socket_by_port:
> health check timer expired
> Feb 28 21:49:10 server1 pgpool[2054]: make_persistent_db_connection:
> connection to server1(5432) failed
> Feb 28 21:49:10 server1 pgpool[2054]: find_primary_node:
> make_persistent_connection failed
> Feb 28 21:49:11 server1 pgpool[2054]: failover: no follow backends are
> degenerated
> Feb 28 21:49:11 server1 pgpool[2054]: failover: set new primary node: -1
> Feb 28 21:49:11 server1 pgpool[2054]: failover: set new master node: 1
> Feb 28 21:49:11 server1 pgpool[4012]: do_child: failback event found.
> restart myself.
> Feb 28 21:49:11 server1 pgpool[4013]: do_child: failback event found.
> restart myself.
> Feb 28 21:49:11 server1 pgpool[4014]: do_child: failback event found.
> restart myself.
> Feb 28 21:49:11 server1 pgpool[4015]: do_child: failback event found.
> restart myself.
>
> Feb 28 21:49:11 server1 pgpool[4030]: do_child: failback event found.
> restart myself.
> Feb 28 21:49:11 server1 pgpool[4039]: do_child: failback event found.
> restart myself.
> Feb 28 21:49:11 server1 pgpool[4040]: connection received:
> host=server1.local port=41474
> Feb 28 21:49:11 server1 pgpool[4040]: read_startup_packet: incorrect packet
> length (0)
> Feb 28 21:49:11 server1 pgpool[4040]: connection received:
> host=server1.local port=41481
> Feb 28 21:49:11 server1 pgpool[4040]: read_startup_packet: incorrect packet
> length (0)
> Feb 28 21:49:11 server1 pgpool[4040]: connection received:
> host=server1.local port=41485
> Feb 28 21:49:11 server1 pgpool[4040]: read_startup_packet: incorrect packet
> length (0)
> Feb 28 21:49:11 server1 pgpool[4040]: connection received:
> host=server1.local port=41491
> Feb 28 21:49:11 server1 pgpool[4040]: read_startup_packet: incorrect packet
> length (0)
> Feb 28 21:49:11 server1 pgpool[2054]: failover done. shutdown host
> server0(5432)
> Feb 28 21:49:11 server1 pgpool[4029]: do_child: failback event found.
> restart myself.
> Feb 28 21:49:12 server1 pgpool[3678]: pcp child process received restart
> request
> Feb 28 21:49:12 server1 pgpool[2054]: PCP child 3678 exits with status 256
> in failover()
> Feb 28 21:49:12 server1 pgpool[2054]: fork a new PCP child pid 4042 in
> failover()
> Feb 28 21:49:12 server1 pgpool[2054]: worker child 3679 exits with status
> 256
> Feb 28 21:49:12 server1 pgpool[2054]: fork a new worker child pid 4043
> Feb 28 21:49:12 server1 pgpool[4043]: connect_inet_domain_socket_by_port:
> health check timer expired
> Feb 28 21:49:12 server1 pgpool[4043]: make_persistent_db_connection:
> connection to server1(5432) failed
> Feb 28 21:49:12 server1 pgpool[2054]: after some retrying backend returned
> to healthy state
> Feb 28 21:49:13 server1 pgpool[4073]: connection received:
> host=server1.local port=41496
> Feb 28 21:49:13 server1 pgpool[4073]: connect_inet_domain_socket_by_port:
> health check timer expired
> Feb 28 21:49:13 server1 pgpool[4073]: connection to server1(5432) failed
> Feb 28 21:49:13 server1 pgpool[4073]: new_connection: create_cp() failed
> Feb 28 21:49:13 server1 pgpool[4073]: degenerate_backend_set: 1 fail over
> request from pid 4073
> Feb 28 21:49:13 server1 pgpool[2054]: starting degeneration. shutdown host
> server1(5432)
> Feb 28 21:49:13 server1 pgpool[2054]: failover_handler: no valid DB node
> found
> Feb 28 21:49:13 server1 pgpool[2054]: Restart all children
> Feb 28 21:49:13 server1 pgpool[2054]: execute command:
> /home/pgpool/failover.py -d 1 -h server1 -p 5432 -D /opt/postgres/9.2/data
> -m -1 -H -M 1 -P 1 -r -R
> Feb 28 21:49:13 server1 pgpool[2054]: find_primary_node_repeatedly: waiting
> for finding a primary node
> Feb 28 21:49:16 server1 pgpool[2057]: wd_lifecheck: lifecheck failed 3
> times. pgpool 0 (server1:9999) seems not to be working
> Feb 28 21:49:16 server1 pgpool[2057]: wd_lifecheck: lifecheck failed 3
> times. pgpool 1 (server0:9999) seems not to be working
> Feb 28 21:49:16 server1 pgpool[2057]: wd_lifecheck: watchdog status is
> DOWN. You need to restart this for recovery.
> Feb 28 21:49:22 server1 pgpool[4043]: connect_inet_domain_socket_by_port:
> health check timer expired
> Feb 28 21:49:22 server1 pgpool[4043]: make_persistent_db_connection:
> connection to server1(5432) failed
> Feb 28 21:49:32 server1 pgpool[4043]: connect_inet_domain_socket_by_port:
> health check timer expired
> Feb 28 21:49:32 server1 pgpool[4043]: make_persistent_db_connection:
> connection to server1(5432) failed
> Feb 28 21:49:35 server1 pgpool[2057]: wd_lifecheck: lifecheck failed 3
> times. pgpool 0 (server1:9999) seems not to be working
> Feb 28 21:49:35 server1 pgpool[2057]: wd_lifecheck: lifecheck failed 3
> times. pgpool 1 (server0:9999) seems not to be working
> Feb 28 21:49:35 server1 pgpool[2057]: wd_lifecheck: watchdog status is
> DOWN. You need to restart this for recovery.
> Feb 28 21:49:42 server1 pgpool[4043]: connect_inet_domain_socket_by_port:
> health check timer expired
>
>
> Question 1: why the failover script did not executed? is it becuase primary
> is -1?
> Question 2: why failover script trigger again?
> Question 3: why pgpool on server1 failed? why watchdog on server1 is down?
>
> Thanks~
> Ning
>
>
>
>
>
> On Wed, Feb 27, 2013 at 10:44 PM, ning chan <ninchan8328 at gmail.com> wrote:
>
>> Hi Tatsuo,
>> I am on 3.2.1. I will try 3.2.3 and report back to you.
>>
>> Meanwhile, I have question about the backend server setting in the
>> pgpool.conf
>> I have two pgpools and each of them pointing to the same backend servers,
>> should both pgpool.conf have the same backend_hostname configuration?
>>
>> *****pgpool-A****
>> backend_hostname0 = 'se032c-94-30'
>> backend_port0 = 5432
>> backend_weight0 = 1
>> backend_data_directory0 = '/opt/postgres/9.2/data'
>> backend_flag0 = 'ALLOW_TO_FAILOVER'
>>
>> backend_hostname1 = 'se032c-94-31'
>> backend_port1 = 5432
>> backend_weight1 = 1
>> backend_data_directory1 = '/opt/postgres/9.2/data'
>> backend_flag1 = 'ALLOW_TO_FAILOVER'
>>
>>
>> ****pgpool-B****
>> backend_hostname0 = 'se032c-94-30'
>> backend_port0 = 5432
>> backend_weight0 = 1
>> backend_data_directory0 = '/opt/postgres/9.2/data'
>> backend_flag0 = 'ALLOW_TO_FAILOVER'
>>
>> backend_hostname1 = 'se032c-94-31'
>> backend_port1 = 5432
>> backend_weight1 = 1
>> backend_data_directory1 = '/opt/postgres/9.2/data'
>> backend_flag1 = 'ALLOW_TO_FAILOVER'
>>
>> Thanks~
>> Ning
>>
>>
>> On Wed, Feb 27, 2013 at 6:12 PM, Tatsuo Ishii <ishii at postgresql.org>wrote:
>>
>>> What version of pgpool-II are you using? We have found a failover
>>> handling problem with 3.2.2 and released 3.2.3 afterwards.
>>> --
>>> Tatsuo Ishii
>>> SRA OSS, Inc. Japan
>>> English: http://www.sraoss.co.jp/index_en.php
>>> Japanese: http://www.sraoss.co.jp
>>>
>>> > Hi Tatsuo,
>>> > Do you have any chance to look at this problem yet?
>>> >
>>> > Thanks~
>>> > Ning
>>> >
>>> >
>>> > On Tue, Feb 19, 2013 at 3:02 PM, ning chan <ninchan8328 at gmail.com>
>>> wrote:
>>> >
>>> >> Hi Tatsuo,
>>> >> I figured out the problem to the some scripting error in the
>>> >> pgpool_remote_start to have the incorrect path to pg_ctl.
>>> >> As soon as I corrected it i can recover the failed server and bring it
>>> >> online.
>>> >> I now however facing another problem.
>>> >> After I bring the failed master back in to the pgpool as a standby
>>> server,
>>> >> i then shutdown the currect Primary server and expecting Standby server
>>> >> will be promoted to become the new Primary; however it did not happen.
>>> >> I check the pgpool log, i see failover command is called but it did not
>>> >> execute. I check and confirm my failover script works just fine.
>>> >>
>>> >> Here is the log:
>>> >> Feb 19 14:51:40 server0 pgpool[3519]: set 1 th backend down status
>>> >> Feb 19 14:51:43 server0 pgpool[3554]: wd_create_send_socket: connect()
>>> >> reports failure (No route to host). You can safely ignore this while
>>> >> starting up.
>>> >> Feb 19 14:51:43 server0 pgpool[3522]: wd_lifecheck: lifecheck failed 3
>>> >> times. pgpool seems not to be working
>>> >> Feb 19 14:51:43 server0 pgpool[3522]: wd_IP_down: ifconfig down
>>> succeeded
>>> >> Feb 19 14:51:43 server0 pgpool[3519]: starting degeneration. shutdown
>>> host
>>> >> server1(5432)
>>> >> Feb 19 14:51:43 server0 pgpool[3519]: Restart all children
>>> >> Feb 19 14:51:43 server0 pgpool[3519]: execute command:
>>> >> /home/pgpool/failover.py -d 1 -h server1 -p 5432 -D
>>> /opt/postgres/9.2/data
>>> >> -m 0 -H server0 -M 0 -P 1 -r 5432 -R /opt/postgres/9.2/data
>>> >> Feb 19 14:51:43 server0 postgres[3939]: [2-1] LOG: incomplete startup
>>> >> packet
>>> >> Feb 19 14:51:43 server0 postgres[3931]: [2-1] LOG: incomplete startup
>>> >> packet
>>> >> Feb 19 14:51:43 server0 postgres[3935]: [2-1] LOG: incomplete startup
>>> >> packet
>>> >> Feb 19 14:51:43 server0 pgpool[3519]: find_primary_node_repeatedly:
>>> >> waiting for finding a primary node
>>> >> Feb 19 14:51:46 server0 pgpool[3522]: wd_create_send_socket: connect()
>>> >> reports failure (No route to host). You can safely ignore this while
>>> >> starting up.
>>> >> Feb 19 14:51:46 server0 pgpool[3522]: wd_lifecheck: lifecheck failed 3
>>> >> times. pgpool seems not to be working
>>> >> Feb 19 14:51:54 server0 pgpool[3556]: connect_inet_domain_socket:
>>> >> connect() failed: Connection timed out
>>> >> Feb 19 14:51:54 server0 pgpool[3556]: make_persistent_db_connection:
>>> >> connection to server1(5432) failed
>>> >> Feb 19 14:51:54 server0 pgpool[3556]: check_replication_time_lag: could
>>> >> not connect to DB node 1, check sr_check_user and sr_check_password
>>> >> Feb 19 14:52:05 server0 pgpool[3522]: wd_lifecheck: lifecheck failed 3
>>> >> times. pgpool seems not to be working
>>> >> Feb 19 14:52:05 server0 pgpool[3556]: connect_inet_domain_socket:
>>> >> connect() failed: No route to host
>>> >> Feb 19 14:52:05 server0 pgpool[3556]: make_persistent_db_connection:
>>> >> connection to server1(5432) failed
>>> >> Feb 19 14:52:05 server0 pgpool[3556]: check_replication_time_lag: could
>>> >> not connect to DB node 1, check sr_check_user and sr_check_password
>>> >> Feb 19 14:52:05 server0 pgpool[3522]: wd_lifecheck: lifecheck failed 3
>>> >> times. pgpool seems not to be working
>>> >> Feb 19 14:52:14 server0 pgpool[3519]: failover: no follow backends are
>>> >> degenerated
>>> >> Feb 19 14:52:14 server0 pgpool[3519]: failover: set new primary node:
>>> -1
>>> >> Feb 19 14:52:14 server0 pgpool[3519]: failover: set new master node: 0
>>> >> Feb 19 14:52:14 server0 pgpool[3980]: connection received:
>>> >> host=server0.local port=45361
>>> >> Feb 19 14:52:14 server0 pgpool[3556]: worker process received restart
>>> >> request
>>> >> Feb 19 14:52:14 server0 pgpool[3519]: failover done. shutdown host
>>> >> server1(5432)
>>> >>
>>> >> As you can see, postgreSQL did not restarted.
>>> >>
>>> >> From a successful failover, the log should looks like this:
>>> >> Feb 19 13:47:01 server0 pgpool[4391]: execute command:
>>> >> /home/pgpool/failover.py -d 1 -h server1 -p 5432 -D
>>> /opt/postgres/9.2/data
>>> >> -m 0 -H server0 -M 0 -P 1 -r 5432 -R /opt/postgres/9.2/data
>>> >> Feb 19 13:47:01 server0 postgres[4786]: [2-1] LOG: incomplete startup
>>> >> packet
>>> >> Feb 19 13:47:02 server0 pgpool[4391]: find_primary_node_repeatedly:
>>> >> waiting for finding a primary node
>>> >> Feb 19 13:47:06 server0 postgres[3083]: [6-1] LOG: trigger file found:
>>> >> /opt/postgres/9.2/data/trigger_file0
>>> >> Feb 19 13:47:06 server0 postgres[3083]: [7-1] LOG: redo done at
>>> 0/91000020
>>> >> Feb 19 13:47:06 server0 postgres[3083]: [8-1] LOG: selected new
>>> timeline
>>> >> ID: 18
>>> >> Feb 19 13:47:06 server0 postgres[3083]: [9-1] LOG: archive recovery
>>> >> complete
>>> >> Feb 19 13:47:06 server0 postgres[3081]: [2-1] LOG: database system is
>>> >> ready to accept connections
>>> >> Feb 19 13:47:06 server0 postgres[4804]: [2-1] LOG: autovacuum launcher
>>> >> started
>>> >> Feb 19 13:47:07 server0 pgpool[4391]: find_primary_node: primary node
>>> id
>>> >> is 0
>>> >> Feb 19 13:47:07 server0 pgpool[4391]: starting follow degeneration.
>>> >> shutdown host server1(5432)
>>> >> Feb 19 13:47:07 server0 pgpool[4391]: failover: 1 follow backends have
>>> >> been degenerated
>>> >> Feb 19 13:47:07 server0 pgpool[4391]: failover: set new primary node: 0
>>> >> Feb 19 13:47:07 server0 pgpool[4391]: failover: set new master node: 0
>>> >> Feb 19 13:47:07 server0 pgpool[4817]: connection received:
>>> >> host=server1.local port=54619
>>> >> Feb 19 13:47:07 server0 pgpool[4816]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4818]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4819]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4815]: start triggering follow command.
>>> >> Feb 19 13:47:07 server0 pgpool[4815]: execute command: echo 1 server1
>>> 5432
>>> >> /opt/postgres/9.2/data 0 server0 0 1 5432 /opt/postgres/9.2/data %
>>> >> Feb 19 13:47:07 server0 pgpool[4821]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4822]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4823]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4820]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4827]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4828]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4826]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4829]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4830]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4831]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4832]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4833]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4834]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4833]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4834]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4835]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4836]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4837]: do_child: failback event found.
>>> >> restart myself.
>>> >> Feb 19 13:47:07 server0 pgpool[4391]: failover done. shutdown host
>>> >> server1(5432)
>>> >>
>>> >> Any idea why failover did not work after the recovery? Do i need to
>>> >> restart remote pgpool after recovery?
>>> >>
>>> >>
>>> >> On Mon, Feb 18, 2013 at 4:24 PM, ning chan <ninchan8328 at gmail.com>
>>> wrote:
>>> >>
>>> >>>
>>> >>> Hi Tatsuo,
>>> >>> Sorry for the late reply as I was traveling.
>>> >>> I am able to reproduce the problem and here is what I did:
>>> >>>
>>> >>> *1) Make sure primary (server0) and standby (server1) connections are
>>> >>> good.*
>>> >>> [root at server0 tmp]# psql -c "show pool_nodes" -p 9999
>>> >>> node_id | hostname | port | status | lb_weight | role
>>> >>> ---------+----------+------+--------+-----------+---------
>>> >>> 0 | server0 | 5432 | 2 | 0.500000 | primary
>>> >>> 1 | server1 | 5432 | 2 | 0.500000 | standby
>>> >>> (2 rows)
>>> >>>
>>> >>> [root at server1 tmp]# psql -c "show pool_nodes" -p 9999
>>> >>> node_id | hostname | port | status | lb_weight | role
>>> >>> ---------+----------+------+--------+-----------+---------
>>> >>> 0 | server0 | 5432 | 2 | 0.500000 | primary
>>> >>> 1 | server1 | 5432 | 2 | 0.500000 | standby
>>> >>> (2 rows)
>>> >>>
>>> >>> *2) force shutdown primary (server0), and standby (server1) server was
>>> >>> promoted, below is the pgpool log from server1 during the failover:*
>>> >>> Feb 18 15:31:45 server1 pgpool[2691]: connect_inet_domain_socket:
>>> >>> connect() failed: No route to host
>>> >>> Feb 18 15:31:45 server1 pgpool[2691]: make_persistent_db_connection:
>>> >>> connection to server0(5432) failed
>>> >>> Feb 18 15:31:45 server1 pgpool[2691]: check_replication_time_lag:
>>> could
>>> >>> not connect to DB node 0, check sr_check_user and sr_check_password
>>> >>> Feb 18 15:31:45 server1 pgpool[2689]: connect_inet_domain_socket:
>>> >>> connect() failed: No route to host
>>> >>> Feb 18 15:31:45 server1 pgpool[2689]: connection to server0(5432)
>>> failed
>>> >>> Feb 18 15:31:45 server1 pgpool[2689]: new_connection: create_cp()
>>> failed
>>> >>> Feb 18 15:31:45 server1 pgpool[2689]: degenerate_backend_set: 0 fail
>>> over
>>> >>> request from pid 2689
>>> >>> Feb 18 15:31:48 server1 pgpool[2689]: wd_create_send_socket: connect()
>>> >>> reports failure (No route to host). You can safely ignore this while
>>> >>> starting up.
>>> >>> Feb 18 15:31:48 server1 pgpool[2653]: connect_inet_domain_socket:
>>> >>> connect() failed: No route to host
>>> >>> Feb 18 15:31:48 server1 pgpool[2653]: make_persistent_db_connection:
>>> >>> connection to server0(5432) failed
>>> >>> Feb 18 15:31:48 server1 pgpool[2653]: health check failed. 0 th host
>>> >>> server0 at port 5432 is down
>>> >>> Feb 18 15:31:48 server1 pgpool[2653]: health check retry sleep time: 5
>>> >>> second(s)
>>> >>> Feb 18 15:31:48 server1 pgpool[2653]: starting degeneration. shutdown
>>> >>> host server0(5432)
>>> >>> Feb 18 15:31:48 server1 pgpool[2653]: Restart all children
>>> >>> Feb 18 15:31:48 server1 pgpool[2653]: execute command:
>>> >>> /home/pgpool/failover.py -d 0 -h server0 -p 5432 -D
>>> /opt/postgres/9.2/data
>>> >>> -m 1 -H server1 -M 0 -P 0 -r 5432 -R /opt/postgres/9.2/data
>>> >>> Feb 18 15:31:49 server1 pgpool[2653]: find_primary_node_repeatedly:
>>> >>> waiting for finding a primary node
>>> >>> Feb 18 15:31:53 server1 postgres[1970]: [7-1] LOG: trigger file
>>> found:
>>> >>> /tmp/trigger_file0
>>> >>> Feb 18 15:31:53 server1 postgres[2597]: [3-1] FATAL: terminating
>>> >>> walreceiver process due to administrator command
>>> >>> Feb 18 15:31:53 server1 postgres[1970]: [8-1] LOG: record with zero
>>> >>> length at 0/64000418
>>> >>> Feb 18 15:31:53 server1 postgres[1970]: [9-1] LOG: redo done at
>>> >>> 0/640003B8
>>> >>> Feb 18 15:31:53 server1 postgres[1970]: [10-1] LOG: selected new
>>> >>> timeline ID: 15
>>> >>> Feb 18 15:31:53 server1 postgres[1970]: [11-1] LOG: archive recovery
>>> >>> complete
>>> >>> Feb 18 15:31:53 server1 postgres[1968]: [2-1] LOG: database system is
>>> >>> ready to accept connections
>>> >>> Feb 18 15:31:53 server1 postgres[3168]: [2-1] LOG: autovacuum
>>> launcher
>>> >>> started
>>> >>> Feb 18 15:31:54 server1 pgpool[2653]: find_primary_node: primary node
>>> id
>>> >>> is 1
>>> >>> Feb 18 15:31:54 server1 pgpool[2653]: starting follow degeneration.
>>> >>> shutdown host server0(5432)
>>> >>> Feb 18 15:31:54 server1 pgpool[2653]: failover: 1 follow backends have
>>> >>> been degenerated
>>> >>> Feb 18 15:31:54 server1 pgpool[2653]: failover: set new primary node:
>>> 1
>>> >>> Feb 18 15:31:54 server1 pgpool[2653]: failover: set new master node: 1
>>> >>> Feb 18 15:31:54 server1 pgpool[3171]: connection received:
>>> >>> host=server1.local port=58346
>>> >>> Feb 18 15:31:54 server1 pgpool[3170]: start triggering follow command.
>>> >>> Feb 18 15:31:54 server1 pgpool[3170]: execute command: echo 0 server0
>>> >>> 5432 /opt/postgres/9.2/data 1 server1 0 0 5432 /opt/postgres/9.2/data
>>> %
>>> >>> Feb 18 15:31:54 server1 pgpool[2691]: worker process received restart
>>> >>> request
>>> >>> Feb 18 15:31:54 server1 pgpool[2653]: failover done. shutdown host
>>> >>> server0(5432)
>>> >>>
>>> >>> *3) boot up the failed server (server0) as usual, pgpool and database
>>> >>> started up as usual.
>>> >>> *
>>> >>> *after server0 boot up, i check the pool_nodes info, server0 pgpool
>>> >>> still think server0 is the primary:*
>>> >>> [root at server0 ~]# psql -c "show pool_nodes" -p 9999
>>> >>> node_id | hostname | port | status | lb_weight | role
>>> >>> ---------+----------+------+--------+-----------+---------
>>> >>> 0 | server0 | 5432 | 2 | 0.500000 | primary
>>> >>> 1 | server1 | 5432 | 2 | 0.500000 | standby
>>> >>> (2 rows)
>>> >>>
>>> >>> server1 pgpool still think server1 is the primary:
>>> >>> [root at server1 tmp]# psql -c "show pool_nodes" -p 9999
>>> >>> node_id | hostname | port | status | lb_weight | role
>>> >>> ---------+----------+------+--------+-----------+---------
>>> >>> 0 | server0 | 5432 | 3 | 0.500000 | standby
>>> >>> 1 | server1 | 5432 | 2 | 0.500000 | primary
>>> >>> (2 rows)
>>> >>>
>>> >>> *4) kill the database on server0 to prepare of the recovery*
>>> >>> *as soon as i kill the server0 database, pgpool log shows following:*
>>> >>> Feb 18 15:33:56 server0 pgpool[2153]: execute command:
>>> >>> /home/pgpool/failover.py -d 0 -h server0 -p 5432 -D
>>> /opt/postgres/9.2/data
>>> >>> -m 1 -H server1 -M 0 -P 0 -r 5432 -R /opt/postgres/9.2/data
>>> >>> Feb 18 15:33:57 server0 pgpool[2153]: find_primary_node_repeatedly:
>>> >>> waiting for finding a primary node
>>> >>> Feb 18 15:33:57 server0 pgpool[2153]: find_primary_node: primary node
>>> id
>>> >>> is 1
>>> >>> Feb 18 15:33:57 server0 pgpool[2153]: starting follow degeneration.
>>> >>> shutdown host server0(5432)
>>> >>> Feb 18 15:33:57 server0 pgpool[2153]: failover: 1 follow backends have
>>> >>> been degenerated
>>> >>> Feb 18 15:33:57 server0 pgpool[2153]: failover: set new primary node:
>>> 1
>>> >>> Feb 18 15:33:57 server0 pgpool[2153]: failover: set new master node: 1
>>> >>> Feb 18 15:33:57 server0 pgpool[2534]: start triggering follow command.
>>> >>> Feb 18 15:33:57 server0 pgpool[2534]: execute command: echo 0 server0
>>> >>> 5432 /opt/postgres/9.2/data 1 server1 0 0 5432 /opt/postgres/9.2/data
>>> %
>>> >>> Feb 18 15:33:57 server0 pgpool[2190]: worker process received restart
>>> >>> request
>>> >>> Feb 18 15:33:57 server0 pgpool[2153]: failover done. shutdown host
>>> >>> server0(5432)
>>> >>>
>>> >>> pool_nodes shows:
>>> >>> [root at server0 ~]# psql -c "show pool_nodes" -p 9999
>>> >>> node_id | hostname | port | status | lb_weight | role
>>> >>> ---------+----------+------+--------+-----------+---------
>>> >>> 0 | server0 | 5432 | 3 | 0.500000 | standby
>>> >>> 1 | server1 | 5432 | 2 | 0.500000 | primary
>>> >>> (2 rows)
>>> >>>
>>> >>>
>>> >>> *5) on server1, execute /usr/local/bin/pcp_recovery_node 10 localhost
>>> >>> 9898 pgpool password 0*
>>> >>> server 1 pgpool log shows following:
>>> >>> Feb 18 15:34:52 server1 pgpool[3209]: starting recovery command:
>>> "SELECT
>>> >>> pgpool_recovery('basebackup.sh', 'server0', '/opt/postgres/9.2/data')"
>>> >>> Feb 18 15:34:53 server1 pgpool[3209]: 1st stage is done
>>> >>> Feb 18 15:34:53 server1 pgpool[3209]: check_postmaster_started: try to
>>> >>> connect to postmaster on hostname:server0 database:postgres
>>> user:postgres
>>> >>> (retry 0 times)
>>> >>> Feb 18 15:34:53 server1 pgpool[3209]: check_postmaster_started:
>>> failed to
>>> >>> connect to postmaster on hostname:server0 database:postgres
>>> user:postgres
>>> >>>
>>> >>> *The message "fail to connect to postmaster on hostname server0"
>>> >>> continue until the command timeout.
>>> >>> *
>>> >>> *it looks like the 1st stage command is done but pgpool on server1 did
>>> >>> not call the pgpool_remote_start to start the server0 database engine
>>> >>> although the script is there under postgresql data folder
>>> >>> *
>>> >>> [root at server1 data]# ls
>>> >>> backup_label.old data pg_hba.conf pg_notify
>>> >>> pg_stat_tmp PG_VERSION postmaster.pid
>>> >>> base global pg_ident.conf pgpool_remote_start
>>> >>> pg_subtrans pg_xlog recovery.done
>>> >>> basebackup.sh ning.test pg_log pg_serial
>>> >>> pg_tblspc postgresql.conf recovery.standby1
>>> >>> copy-base-backup.sh pg_clog pg_multixact pg_snapshots
>>> >>> pg_twophase postmaster.opts
>>> >>>
>>> >>> *during this period, pgpool log on server0 shows the following:*
>>> >>> Feb 18 15:34:42 server0 pgpool[2567]: connection received:
>>> >>> host=server0.local port=45366
>>> >>> Feb 18 15:34:46 server0 pgpool[2567]: connection received:
>>> >>> host=server1.local port=39535
>>> >>> Feb 18 15:34:52 server0 pgpool[2567]: connection received:
>>> >>> host=server0.local port=45381
>>> >>> Feb 18 15:34:56 server0 pgpool[2565]: connection received:
>>> >>> host=server1.local port=39557
>>> >>> Feb 18 15:35:02 server0 pgpool[2565]: connection received:
>>> >>> host=server0.local port=45396
>>> >>> Feb 18 15:35:06 server0 pgpool[2565]: connection received:
>>> >>> host=server1.local port=39576
>>> >>> Feb 18 15:35:12 server0 pgpool[2565]: connection received:
>>> >>> host=server0.local port=45410
>>> >>> Feb 18 15:35:16 server0 pgpool[2565]: connection received:
>>> >>> host=server1.local port=39593
>>> >>> Feb 18 15:35:22 server0 pgpool[2565]: connection received:
>>> >>> host=server0.local port=45425
>>> >>> Feb 18 15:35:26 server0 pgpool[2565]: connection received:
>>> >>> host=server1.local port=39612
>>> >>> Feb 18 15:35:32 server0 pgpool[2565]: connection received:
>>> >>> host=server0.local port=45440
>>> >>> Feb 18 15:35:36 server0 pgpool[2565]: connection received:
>>> >>> host=server1.local port=39630
>>> >>> Feb 18 15:35:42 server0 pgpool[2565]: connection received:
>>> >>> host=server0.local port=45455
>>> >>> Feb 18 15:35:46 server0 pgpool[2565]: connection received:
>>> >>> host=server1.local port=39648
>>> >>>
>>> >>> *Below is the script of recovery_1st_stage_command = 'basebackup.sh'*
>>> >>> [root at server1 ~]# more /opt/postgres/9.2/data/basebackup.sh
>>> >>> #! /bin/sh
>>> >>> # Recovery script for streaming replication.
>>> >>> # This script assumes that DB node 0 is primary, and 1 is standby.
>>> >>> #
>>> >>> datadir=$1
>>> >>> desthost=$2
>>> >>> destdir=$3
>>> >>>
>>> >>> echo "datadir=$datadir"
>>> >>> echo "desthost=$desthost"
>>> >>> echo "destdir=$destdir"
>>> >>>
>>> >>> echo "Executing basebackup.sh" >> /var/log/replication.log
>>> >>>
>>> >>> echo "Executing start backup" >> /var/log/replication.log
>>> >>> psql -c "SELECT pg_start_backup('Streaming Replication', true)"
>>> postgres
>>> >>>
>>> >>> echo "Executing rsync" >> /var/log/replication.log
>>> >>> echo "rsync -C -a --progress --delete -e ssh --exclude postgresql.conf
>>> >>> --exclude postmaster.pid --exclude postmaster.
>>> >>> opts --exclude pg_log --exclude pg_xlog --exclude recovery.conf
>>> $datadir/
>>> >>> $desthost:$destdir/"
>>> >>>
>>> >>> echo "Renaming recovery conf file" >>/var/log/replication.log
>>> >>> echo "ssh -T $desthost mv $destdir/recovery.done
>>> $destdir/recovery.conf"
>>> >>> ssh -T $desthost mv $destdir/recovery.done $destdir/recovery.conf
>>> >>>
>>> >>> echo "Removing trigger file"
>>> >>> ssh -T $desthost rm -f /tmp/trigger_file0
>>> >>>
>>> >>> echo "Executing stop backup" >> /var/log/replication.log
>>> >>> psql -c "SELECT pg_stop_backup()" postgres
>>> >>>
>>> >>> echo "existing basebackup.sh" >> /var/log/replication.log
>>> >>>
>>> >>> *Manually execute the command on server1 return the following result:*
>>> >>>
>>> >>> [root at server1 data]# ./basebackup.sh /opt/postgres/9.2/data/ server0
>>> >>> /opt/postgres/9.2/data/
>>> >>> datadir=/opt/postgres/9.2/data/
>>> >>> desthost=server0
>>> >>> destdir=/opt/postgres/9.2/data/
>>> >>> pg_start_backup
>>> >>> -----------------
>>> >>> 0/76000020
>>> >>> (1 row)
>>> >>>
>>> >>> rsync -C -a --progress --delete -e ssh --exclude postgresql.conf
>>> >>> --exclude postmaster.pid --exclude postmaster.opts --exclude pg_log
>>> >>> --exclude pg_xlog --exclude recovery.conf /opt/postgres/9.2/data//
>>> >>> server0:/opt/postgres/9.2/data//
>>> >>> ssh -T server0 mv /opt/postgres/9.2/data//recovery.done
>>> >>> /opt/postgres/9.2/data//recovery.conf
>>> >>> Removing trigger file
>>> >>> NOTICE: WAL archiving is not enabled; you must ensure that all
>>> required
>>> >>> WAL segments are copied through other means to complete the backup
>>> >>> pg_stop_backup
>>> >>> ----------------
>>> >>> 0/760000E0
>>> >>> (1 row)
>>> >>>
>>> >>> Thanks and please advise.
>>> >>>
>>> >>> Ning
>>> >>>
>>> >>>
>>> >>> On Sun, Feb 17, 2013 at 7:05 AM, Tatsuo Ishii <ishii at postgresql.org
>>> >wrote:
>>> >>>
>>> >>>> Hi,
>>> >>>>
>>> >>>> It seems the standby was unable to start up. Can you show standby
>>> >>>> PostgreSQL's log? Maybe we could find the cause of the problem.
>>> >>>> --
>>> >>>> Tatsuo Ishii
>>> >>>> SRA OSS, Inc. Japan
>>> >>>> English: http://www.sraoss.co.jp/index_en.php
>>> >>>> Japanese: http://www.sraoss.co.jp
>>> >>>>
>>> >>>> > Hi Tatsuo,
>>> >>>> > Thank you so much for your reply.
>>> >>>> > Actually in my case, i was using the pcp_recovery command and
>>> execute
>>> >>>> it on
>>> >>>> > the current primary server.
>>> >>>> > However, if the remote node (recover node) database is off, i got
>>> the
>>> >>>> > following message on the primary server pgpool log:
>>> >>>> >
>>> >>>> > Jan 31 16:58:10 server0 pgpool[2723]: starting recovery command:
>>> >>>> "SELECT
>>> >>>> > pgpool_recovery('basebackup.sh', 'server1',
>>> '/opt/postgres/9.2/data')"
>>> >>>> > Jan 31 16:58:11 server0 pgpool[2723]: 1st stage is done
>>> >>>> > Jan 31 16:58:11 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:postgres
>>> >>>> user:postgres
>>> >>>> > (retry 0 times)
>>> >>>> > Jan 31 16:58:11 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:postgres
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:13 server0 pgpool[2719]: connection received:
>>> >>>> > host=server0.local port=58446
>>> >>>> > Jan 31 16:58:14 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:postgres
>>> >>>> user:postgres
>>> >>>> > (retry 1 times)
>>> >>>> > Jan 31 16:58:14 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:postgres
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:14 server0 pgpool[2719]: connection received:
>>> >>>> > host=server1.local port=39928
>>> >>>> > Jan 31 16:58:17 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:postgres
>>> >>>> user:postgres
>>> >>>> > (retry 2 times)
>>> >>>> > Jan 31 16:58:17 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:postgres
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:20 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:postgres
>>> >>>> user:postgres
>>> >>>> > (retry 3 times)
>>> >>>> > Jan 31 16:58:20 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:postgres
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:23 server0 pgpool[2719]: connection received:
>>> >>>> > host=server0.local port=58464
>>> >>>> > Jan 31 16:58:23 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > (retry 0 times)
>>> >>>> > Jan 31 16:58:23 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:26 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > (retry 1 times)
>>> >>>> > Jan 31 16:58:26 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:26 server0 pgpool[2719]: connection received:
>>> >>>> > host=server1.local port=39946
>>> >>>> > Jan 31 16:58:29 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > (retry 2 times)
>>> >>>> > Jan 31 16:58:29 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:32 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > (retry 3 times)
>>> >>>> > Jan 31 16:58:32 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:33 server0 pgpool[2719]: connection received:
>>> >>>> > host=server0.local port=58483
>>> >>>> > Jan 31 16:58:35 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > (retry 4 times)
>>> >>>> > Jan 31 16:58:35 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > Jan 31 16:58:38 server0 pgpool[2723]: check_postmaster_started:
>>> try to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> > (retry 5 times)
>>> >>>> > Jan 31 16:58:38 server0 pgpool[2723]: check_postmaster_started:
>>> failed
>>> >>>> to
>>> >>>> > connect to postmaster on hostname:server1 database:template1
>>> >>>> user:postgres
>>> >>>> >
>>> >>>> > here is the exact command i execute on server0 to recover server1,
>>> >>>> > /usr/local/bin/pcp_recovery_node 10 localhost 9898 pgpool password
>>> 1
>>> >>>> >
>>> >>>> > Do you have any idea why?
>>> >>>> >
>>> >>>> > Just FYI, we cannot pgpoolAdmin in our environment.
>>> >>>> >
>>> >>>> >
>>> >>>> > On Sun, Feb 17, 2013 at 12:13 AM, Tatsuo Ishii <
>>> ishii at postgresql.org>
>>> >>>> wrote:
>>> >>>> >
>>> >>>> >> > Hi all,
>>> >>>> >> > I have the following question regarding the recovery of a filed
>>> >>>> Primary
>>> >>>> >> > Database Server.
>>> >>>> >> >
>>> >>>> >> > Question 1: in the documentation, under Streaming Replication
>>> Online
>>> >>>> >> > Recovery section.
>>> >>>> >> >
>>> >>>> >> > http://www.pgpool.net/docs/latest/pgpool-en.html#stream
>>> >>>> >> >
>>> >>>> >> > in steps 6:
>>> >>>> >> >
>>> >>>> >> > 1. After completing online recovery, pgpool-II will start
>>> >>>> PostgreSQL
>>> >>>> >> on
>>> >>>> >> > the standby node. Install the script for this purpose on
>>> each DB
>>> >>>> >> > nodes. Sample
>>> >>>> >> > script <
>>> http://www.pgpool.net/docs/latest/pgpool_remote_start>
>>> >>>> is
>>> >>>> >> > included in "sample" directory of the source code. This
>>> script
>>> >>>> uses
>>> >>>> >> ssh.
>>> >>>> >> > You need to allow recovery_user to login from the primary
>>> node
>>> >>>> to the
>>> >>>> >> > standby node without being asked password.
>>> >>>> >> >
>>> >>>> >> > To my understanding, i think the postgreSQL doesn't not need to
>>> be
>>> >>>> online
>>> >>>> >> > for the recovery process right? Since later on it mentions that
>>> >>>> >> > pgpool_remote_start will start up the DB on the failed node.
>>> >>>> >>
>>> >>>> >> Acually standby PostgreSQL node should not be started.
>>> >>>> >>
>>> >>>> >> > Question 2: in my configuration, i have 2 pgpool server with two
>>> >>>> >> backends.
>>> >>>> >> > Will it work for oneline recovery?
>>> >>>> >>
>>> >>>> >> Yes, but online recovery process should be initiated by one of
>>> pgpool,
>>> >>>> >> not both. If you enable pgpool-II 3.2's watchdog, it will take
>>> care of
>>> >>>> >> neccessary interlocking.
>>> >>>> >>
>>> >>>> >> > Question 3: when the failed node comes back online, should i use
>>> >>>> >> > pcp_recovery from DB primary or should i use pcp_attach on the
>>> >>>> failed
>>> >>>> >> node
>>> >>>> >> > to recover the failed system? Actually in my case, both methods
>>> do
>>> >>>> not
>>> >>>> >> > recover my system every time.
>>> >>>> >>
>>> >>>> >> I'm confused. Didn't you start the online recovery process by
>>> using
>>> >>>> >> pcp_recovery_node?(of course you could do it via pgpoolAdmin).
>>> >>>> >>
>>> >>>> >> Anyway pcp_recovery_node automatically attach recovered node, and
>>> you
>>> >>>> >> don't need to execute pcp_attach_node.
>>> >>>> >>
>>> >>>> >> I suggest you read tutorial:
>>> >>>> >>
>>> >>>>
>>> http://www.pgpool.net/pgpool-web/contrib_docs/simple_sr_setting2/index.html
>>> >>>> >> --
>>> >>>> >> Tatsuo Ishii
>>> >>>> >> SRA OSS, Inc. Japan
>>> >>>> >> English: http://www.sraoss.co.jp/index_en.php
>>> >>>> >> Japanese: http://www.sraoss.co.jp
>>> >>>> >>
>>> >>>>
>>> >>>
>>> >>>
>>> >>
>>>
>>
>>
More information about the pgpool-general
mailing list