I have been thinking about this and wanted to see if it can be achived. I wanted to make a 100% failover solution for my postgres databases. The first thing that comes to my mind is doing it using WAL logs. Am attaching the diagram for which i will write more here.
I was thinking if i can have Hotsync the databases using the WAL logs. If you see the architecture, the select goes to the SLAVE nodes and the INSERTS goes to the MASTER database, that means there should be no transactions happening on SLAVES (pure select). not even using "plpgsql". In this archecture i wont even mind restarting the SLAVE nodes if i need to.
I was reading on PIT recovery on postgres, the only current problem i am facing with that is, i need to backup the database and move the slaves and the apply WAL logs to it. That could be huge amount of transfer and hence a longer downtime then moving 16mb WAL log files.
Can someone help me out here, what i want is a continuous applying of WAL logs once i have brought the database up. I want to elimiate the backup of master to be restored to the slaves everytime i want to apply WAL to slaves. It would be real help if someone can tell me if it is possible to apply WAL logs to the slaves continously as soon as they are created on MASTER. I checked other tools available and thougth this would be best approach if it works.
