in our setup the show pool_nodes shows a very high replication_delay and it keeps increasing, becuase of which any new queries are not replicated in the slave
following is the output of show pool_nodes command, is there a way to reset this, data loss if fine as this is not a live/production system.
[root#DB2 ~]# psql -h DB-HA-Hostname -U postgres -p 5432 -c 'show pool_nodes'
node_id | hostname | port | status | lb_weight | role | select_cnt | load_balance_node | replication_delay | last_status_change
---------+--------------------------------------+------+--------+-----------+---------+------------+-------------------+-------------------+---------------------
0 | DB1-hostname | 5432 | up | 0.500000 | primary | 0 | true | 0 | 2021-01-11 19:32:00
1 | DB2-hostname | 5432 | up | 0.500000 | standby | 0 | false | 54986528 | 2021-01-11 19:32:00
(2 rows)
I have tried, restarting nodes, restarting pgpool, restarting postgresql , deleting database etc.. but no luck. As soon as the slave gets attached the replication_delay is high again..
You can run this command to check status of replication:
psql -h DB-HA-Hostname -U postgres -p 5432 -c "select * from pg_stat_replication" -x
if it shows:
if not, the configuration has failed.
You can show your configuration ?
Check the replication is running or not if it's not running re-configure the standby then attached the nodes
select * from pg_stat_replication;
after taking basebackup start the postgresql server then pcp-attach-node on pgpool
Related
I am trying to setup a Primary and a standby using repmgr. I think I have successfully setup master, but standby setup keeps failing.
On Standby node
/usr/pgsql-12/bin/repmgr -h master_ip standby clone
NOTICE: destination directory "/var/lib/pgsql/12/data" provided
INFO: connecting to source node
DETAIL: connection string is: host=master_ip
DETAIL: current installation size is 32 MB
ERROR: repmgr extension is available but not installed in database "(null)"
HINT: check that you are cloning from the database where "repmgr" is installed
On Master Node:
/usr/pgsql-12/bin/repmgr cluster show
ID | Name | Role | Status | Upstream | Location | Priority | Timeline | Connection string
----+-------------+---------+-----------+----------+----------+----------+----------+----------------------------------------------------------------
1 | hostname | primary | * running | | default | 100 | 1 | host=master_ip dbname=repmgr user=repmgr connect_timeout=2
postgres=# SELECT * FROM pg_available_extensions WHERE name='repmgr';
name | default_version | installed_version | comment
--------+-----------------+-------------------+------------------------------------
repmgr | 5.3 | | Replication manager for PostgreSQL
resolved after adding -U repmgr -d repmgr to the clone command.
I'm trying to use pgpool to postgres HA.
node_id | hostname | port | status | pg_status | lb_weight | role | pg_role | select_cnt | load_bala
nce_node | replication_delay | replication_state | replication_sync_state | last_status_change
---------+----------+------+--------+-----------+-----------+---------+---------+------------+----------
---------+-------------------+-------------------+------------------------+---------------------
0 | master | 5432 | up | up | 0.500000 | primary | primary | 1 | false
| 0 | | | 2022-05-30 10:33:21
1 | slave | 5432 | up | up | 0.500000 | standby | primary | 0 | true
| 419431440 | | | 2022-05-30 10:33:21
In this process, other process is working well, but I got empty value replictation_state and replication_sync_state.
And I got high value in replication_delay.
Why those values are empty and high value?
Is there should change values in postgres.conf or pgpool.conf for replication?
In this case, I used 'pg_basebackup -h host -U Repuser -p port -D dir -X stream' for slave
this is pcp_node_info's result
master 5432 2 0.500000 up up primary primary 0 none none 2022-05-30 10:42:40
slave 5432 2 0.500000 up up standby primary 419431848 none none 2022-05-30 10:42:40
Sorry to my English Level, Thank you for your help
My version
postgres 14.2
pgpool 4.3.1
You need to provide application_name in both configurations files - myrecovery.conf (primary_conninfo variable) and pgpool.conf for each node.
Also you should check recovery_1st_stage and follow_primary.sh files as there you also find block with application_name. Script are used by pgpool to recover replica (with pcp_recover_node) or promote new master.
After all you can check current value with "select * from pg_stat_replication;" (on master) or "select * from pg_stat_wal_receiver;" (on replica)
More information: https://www.pgpool.net/docs/pgpool-II-4.3.1/en/html/example-cluster.html
I have trouble backing up a PostgreSQL database. When I run the following command:
psql -d cdb -U "$(whoami)"
The result:
cdb=# \c
You are now connected to database "cdb" as user "gub".
So no problems with that. However when I run
pg_dump -h localhost -p 5432 -U "$(whoami)" -d cdb -w -C -F p -b -f /home/"$(whoami)"/cdb.sql
I get the following error message:
pg_dump: error: connection to database "cdb" failed: fe_sendauth: no password supplied
I have the following auth settings:
cdb=# select * from pg_hba_file_rules;
line_number | type | database | user_name | address | netmask | auth_method | options | error
-------------+-------+---------------+------------+-----------+-----------------------------------------+-------------+---------+-------
89 | local | {all} | {postgres} | | | peer | |
94 | local | {all} | {all} | | | peer | |
96 | host | {all} | {all} | 127.0.0.1 | 255.255.255.255 | md5 | |
98 | host | {all} | {all} | ::1 | ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff | md5 | |
101 | local | {replication} | {all} | | | peer | |
102 | host | {replication} | {all} | 127.0.0.1 | 255.255.255.255 | md5 | |
103 | host | {replication} | {all} | ::1 | ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff | md5 | |
I am not sure why this is not working as auth_method peer should not require a password. Can someone please help? postgresql.conf has not been changed and setup is: psql (PostgreSQL) 12.9 (Ubuntu 12.9-0ubuntu0.20.04.1)
My goal is to backup without the need of a password.
With psql, you are using a local connection via domain sockets, since you didn't specify -h localhost, so the first or second pg_hba.conf line applies, and you can connect without a password.
With pg_dump, you are using a TCP connection, and the third or fourth line applies, and you have to supply a password.
Omit -h localhost!
After performing a fail over, I had the previous Primary down, and the old standby became the Primary, as expected.
$ repmgr -f /etc/repmgr.conf cluster show --compact
ID | Name | Role | Status | Upstream | Location | Prio. | TLI
----+-----------------+---------+-----------+----------+----------+-------+-----
1 | server1 | primary | - failed | | default | 100 | ?
2 | server2 | primary | * running | | default | 100 | 2
3 | PG-Node-Witness | witness | * running | server2 | default | 0 | 1
I would like to make the old Primary join the cluster as a standby.
I gather the rejoin command should do that.
However, when I try to rejoin it, to be the new standby, I get this (I run this on the old Primary which is down ):
repmgr -f /etc/repmgr.conf -d 'host=10.9.7.97 user=repmgr dbname=repmgr' node rejoin
--where 10.9.7.97 is the ip of node I am running from.
I get this error:
$ repmgr -f /etc/repmgr.conf -d 'host=10.97.7.97 user=repmgr dbname=repmgr' node rejoin --verbose -
NOTICE: using provided configuration file "/etc/repmgr.conf"
ERROR: connection to database failed
DETAIL:
could not connect to server: Connection refused
Is the server running on host "10.97.7.97" and accepting
TCP/IP connections on port 5432?
Of course postgres is down on 10.9.7.97 - the old primary.
If I start it however, it starts as another primary:
$ repmgr -f /etc/repmgr.conf cluster show --compact
ID | Name | Role | Status | Upstream | Location | Prio. | TLI
----+-----------------+---------+-----------+----------+----------+-------+-----
1 | server1 | primary | ! running | | default | 100 | 1
2 | server2 | primary | * running | | default | 100 | 2
3 | PG-Node-Witness | witness | * running | server2 | default | 0 | 1
so what is the way to make the old primary the new standby...?
Thanks
Apparently the
-d 'host=
in the rejoin command, should specify the current Primary (previous standby).
I'm running a Postgres inside a docker container. I want to change the default config of Postgres so I'm running:
docker container run -d postgres -c max_connections=200 -c shared_buffers=1GB -c effective_cache_size=3GB -c maintenance_work_mem=256MB -c checkpoint_completion_target=0.7 -c wal_buffers=16MB
But when I'm connecting to Postgres running:
docker exec -it container_name psql
And then the result of :
SHOW max_connections;
is
max_connections
-----------------
100
(1 row)
And it's not just max_connections. None of the parameters are changed. And I don't know what is the problem with what I'm doing?
Update: the result of
root=# SELECT *
root-# FROM pg_settings
root-# WHERE name = 'max_connections';
is
name | setting | unit | category | short_desc | extra_desc | context | vartype | source | min_val | max_val | enumvals | boot_val | reset_val | sourcefile | sourceline | pending_restart
-----------------+---------+------+------------------------------------------------------+----------------------------------------------------+------------+------------+---------+--------------------+---------+---------+----------+----------+-----------+------------------------------------------+------------+-----------------
max_connections | 100 | | Connections and Authentication / Connection Settings | Sets the maximum number of concurrent connections. | | postmaster | integer | configuration file | 1 | 262143 | | 100 | 100 | /var/lib/postgresql/data/postgresql.conf | 64 | f
(1 row)
If you cannot get it to work while starting the server, try ALTER SYSTEM:
psql -c "ALTER SYSTEM SET max_connections=200; SELECT pg_reload_conf()"
That changes the setting in postgresql.auto.conf.
Changing shared_buffers, wal_buffersandmax_connections` require a restart of the PostgreSQL server, the other parameters can be changed on the fly.
Is it possible that you are connecting to the wrong container? When I try to run psql as you have, I get:
$ docker exec -it boring_hermann psql
psql: FATAL: role "root" does not exist
...because the standard user is root and has no access to the container's DB. When I run as user 999, group 999 (the one listed as postgres in that image), it works correctly:
$ docker exec -u 999:999 -it boring_hermann psql
psql (11.1 (Debian 11.1-1.pgdg90+1))
Type "help" for help.
postgres=# show max_connections;
max_connections
-----------------
200
(1 row)