wal copies for high availability - Mailing list pgsql-general

Hi,

 

Our IT budget is not so much and even so I´m trying to set up a Postgresql high availability solution for our business.

My managers gave me the following statements that I must follow:

. the system could be out of service no more than 2 hours
. last 5 minutes of work could be lost

 

The first choice was to use slony-i and a master/slave configuration, but I could not use it because we have many tables without primary keys and the software house will charge us a lot to make this kind of modification.

 

Another cheap alternative is diarly (00:00) stop the master database and make a copy of the $PGDATA directory to the slave and during the day make regularly (5 x 5 minutes) copies of the current wal file to the slave too.

 

To recover the system we need only to apply all the logs created during the day to the slave and sta rt it up.

 

Will it work?
Is there any risk to make it in this way?
What will happen if during the wal copy operation the database writes something in too?
Will the wal file copied usefull in those situations?
What other alternatives do we have?

 

Thanks in advance!

 

Streit