On Mon, Jan 5, 2015 at 6:51 PM, Edson Carlos Ericksson Richter <edsonrichter@xxxxxxxxxxx> wrote: > Would this kind of count being recorded somewhere else? > How does the server knows that the wal_segments have been exhausted? You should evaluate the amount of wal_keep_segments necessary using the replication lag in terms of WAL position differences (LSN) between the master and its slaves. pg_stat_replication gives you the WAL position (LSN) up to where each slave has received WAL information. Combine it with pg_current_xlog_location() to determine what is the current location master is writing WAL and you can evaluate the number of WAL files that need to be retained on master. Knowing that each WAL file is normally 16MB, simply use pg_xlog_location_diff to calculate the WAL lag as a difference of bytes (for 9.4 a simple difference operation is possible with the data type pg_lsn), and then guess from it the number of WAL files that are actually necessary. If you care that much about WAL retention btw, consider using replication slots with 9.4, just be careful to monitor the partition where pg_xlog sits in. -- Michael -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
