Zabbix HA via postgres replication.

[pietro54]

Hello,
I dont know if toppic describe whole idea, but I need to make some High Availability on my Zabbix server.

I got 2 idenical machines, identical os configurations,
Zabbix 2.0.4, postgres 9.1.6, RH 6.3
I made replication between postgres databases
Idea form: http://wiki.postgresql.org/wiki/Streaming_Replication
Replication work ok. Wal`s are swimming from node1 to node2.

I copy all /etc/sysconfig/network-scripts to node2(only change mac of cards)
All Ifaces are now down, they waiting to start network service(when first node goes down).
Only one thing is problem, when i come into http://localhost/zabbix via browser i got configuration screan i can`t go further, becouse my db is in RO mode, what shoul I do?
Copy some .conf file from node1? What file? (couse /var/www/html/conf/zabbix.conf.php isent helping)


When the problem with "configuration" will be solved I want to simulate pull over power cables from node1.
What should i do next? Database fromn node2 will automaticli take master role?
or shoul i something do else?

Regards
Piotr

[f.koch]

Hi,

you need to say postgresql to go into master mode

http://www.postgresql.org/docs/9.1/interactive/standby-settings.html

regards fl0

[pietro54]

Hello,
Thanks for replay, pg_ctl promote works ok!

1)But maybe You can tell me what value should be in string :trigger_file ??
i don`t understated "Specifies a trigger file whose presence ends recovery in the standby. Even if this value is not set, you can still promote the standby using pg_ctl promote. This setting has no effect if standby_mode is off."

I will be glad if this will work automatically.

--Edit--
2) When i promote standby - node2 and use it for a while, I want to back to node1,
I started base on node1 but it starts with postgres: wal writer process
not with sender, what should I do? unpromote node2 ?

Node1

/usr/pgsql-9.1/bin/pg_ctl promote
pg_ctl: cannot promote server; server is not in standby mode
-bash-4.1$ ps uax | grep wal
postgres 11979 0.0 0.0 8791312 6672 ? Ss 13:37 0:00 postgres: wal writer process

I did not change anything in postgres config. Maybe some one will know how to return sender process?



3)One more curious thing,
When I shut down database and start after one minute all of triggers "host is unreachable" send me false alarms.
Is there possibility to escape from this problem? Im getting over 200mails

[pietro54]

Hello,
Can anyone tell me how to promote first node to be a sender again?

Regards
Piotr