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Note use of phbouncer %include directive

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Ian Barwick
2016-11-23 09:33:30 +09:00
parent 2588853e83
commit d2f4eda224
1 changed files with 18 additions and 18 deletions
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36
docs/repmgrd-node-fencing.md
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@@ -22,15 +22,14 @@ of this document).
* * * * * *
In a failover situation, `repmgrd` promotes a standby to master by In a failover situation, `repmgrd` promotes a standby to master by executing
executing the command defined in `promote_command`. Normally this the command defined in `promote_command`. Normally this would be something like:
would be something like:
repmgr standby promote -f /etc/repmgr.conf repmgr standby promote -f /etc/repmgr.conf
By wrapping this in a custom script which adjusts the `pgbouncer` By wrapping this in a custom script which adjusts the `pgbouncer` configuration
configuration on all nodes, it's possible to fence the failed master on all nodes, it's possible to fence the failed master and redirect write
and redirect write connections to the new master. connections to the new master.
The script consists of three sections: The script consists of three sections:
@@ -38,20 +37,19 @@ The script consists of three sections:
* the promotion command itself * the promotion command itself
* commands to reconfigure and restart `pgbouncer` on all nodes * commands to reconfigure and restart `pgbouncer` on all nodes
Note that it requires password-less SSH access between all nodes to be Note that it requires password-less SSH access between all nodes to be able to
able to update the `pgbouncer` configuration files. update the `pgbouncer` configuration files.
For the purposes of this demonstration, we'll assume there are 3 nodes For the purposes of this demonstration, we'll assume there are 3 nodes (master
(master and two standbys), with `pgbouncer` listening on port 6432 and two standbys), with `pgbouncer` listening on port 6432 handling connections
handling connections to a database called `appdb`. The `postgres` to a database called `appdb`. The `postgres` system user must have write
system user must have write access to the `pgbouncer` configuration access to the `pgbouncer` configuration files on all nodes. We'll assume
file on all nodes, assumed to be at `/etc/pgbouncer.ini`. there's a main `pgbouncer` configuration file, `/etc/pgbouncer.ini`, which uses
the `%include` directive (available from PgBouncer 1.6) to include a separate
configuration file, `/etc/pgbouncer.database.ini`, which will be modified by
`repmgr`.
The script also requires a template file containing global `pgbouncer` `/etc/pgbouncer.ini` should look something like this:
configuration, which should looks something like this (adjust
settings appropriately for your environment):
`/var/lib/postgres/repmgr/pgbouncer.ini.template`
[pgbouncer] [pgbouncer]
@@ -80,6 +78,8 @@ settings appropriately for your environment):
log_disconnections = 1 log_disconnections = 1
log_pooler_errors = 1 log_pooler_errors = 1
%include /etc/pgbouncer.database.ini
The actual script is as follows; adjust the configurable items as appropriate: The actual script is as follows; adjust the configurable items as appropriate:
`/var/lib/postgres/repmgr/promote.sh` `/var/lib/postgres/repmgr/promote.sh`