Showing posts from October, 2015

PostgreSQL 9.4 streaming replication over SSL with Replication Slots

I never really liked the concept of keeping wal files in case the replica goes down proactively, setting wal_keep_segments was always a tricky number and most of the time we ended up setting this for the worst case scenario, something that means space consumption for no (under normal circumstances) good reason. That’s why i really like replication slots. Replication slots are, and i am quoting Robert Haas : "a crash-safe data structure which can be created on either a master or a standby to prevent premature removal of write-ahead log segments needed by a standby, as well as (with hot_standby_feedback=on) pruning of tuples whose removal would cause replication conflicts. Slots have some advantages over existing techniques, as explained in the documentation." While there are a lot of posts about how to setup replication slots, and to be honest its pretty easy, in this post i will combine this with replication over SSL and i will also show a useful trick for pg_basebackup (pr