How do you manage the failover with your virtual servers ?
Postgres has a built-in failover mecanism using the trigger_file setting in reconvery.conf.
Do you handle it manually or use another system to automate it ?
Robin.
De : Poul Kristensen <bcc5226@gmail.com> Envoyé : jeudi 6 avril 2017 18:16 À : Robin LUCBERNET Cc : pgsql-admin@postgresql.org Objet : Re: [ADMIN] How do you manage cluster replication and failover ?
The challenge is not whether to use the difference tools as you mentioned. The challenge is to make to optimal database design the get the optimal backup/restore or disaster/recovery.
If you have just one database per Postgres installation and then just handle user/role security using schema's in one database then it is a good choice in my opinion as only one installation to maintain.
If you have multiple databases I think that you have to be aware of issues concerning the recovering of one database in an easy way. Furthermore be aware of the possibilty of corrupted databases. A regularly dump will help. If using Debian's hdparm -I /dev/.. is usefull on Debian.
Write performance: I have succeded writing 10 mill. records in 50seconds using 2 virtual servers with streaming replication. I haven't yet tried physical servers yet.
We are currently trying to setup a multi hosts databases cluster with goals: * replication (no data-loss is "required", replication timing do not needs to be instant) * failover * load-balancing (bonus)
We tried: * synchronious replication (pgpool replication mode) + load-balancing (pgpool) : very interesing as we can theorically failover on any node at any moment. But even after several configuraation tweeks, we never succeed getting good write performance. * asynchronious replication (postgres 9.6 streaming replication) : good write performance, good replication timings (< 1 second for small transactions). We could loadbalance select requests using pgpool.
How do you manage your postgresql clusters ? Do you use pgpool ? pgbouncer ? other ? How do you manage to single access point ? usign pgpool ? pgbouncer ? Do you use streaming replication ? WAL archiving ? How do you handle to automatic failover ?
Robin
--
Med venlig hilsen / Best regards Poul Kristensen Linux-OS/Virtualizationexpert and Oracle DBA