Here is the situation: I have a standby postgres which is fed a WAL File every 2 minutes. Whenever it is fed a WAL file it logs the following: --- LOG: restored log file "000000010000000000000070" from archive pg_restore::copyWALFile: Moving /opt/data/mirror/000000010000000000000071 to pg_xlog/RECOVERYXLOG LOG: restored log file "000000010000000000000071" from archive pg_restore::copyWALFile: Moving /opt/data/mirror/000000010000000000000072 to pg_xlog/RECOVERYXLOG LOG: restored log file "000000010000000000000072" from archive ... ... pg_restore::copyWALFile: Moving /opt/data/mirror/000000010000000000000082 to pg_xlog/RECOVERYXLOG LOG: restored log file "000000010000000000000082" from archive --- I assume that the above situation is a happy postgres in a recovery mode. The "copyWALFile" is my message in the serverlog. After a while, the primary gives up. That is it goes down and I am not able to pull any WAL file from the primary. So I tell the standby that I do not have any WAL File to give. ---- LOG: could not open file "pg_xlog/000000010000000000000083" (log file 0, segment 131): No such file or directory LOG: redo done at 0/8200D280 Main: Triggering recovery PANIC: could not open file "pg_xlog/000000010000000000000082" (log file 0, segment 130): No such file or directory --- The issue above is that I do not have the "001...0083" file and I return a "file not found". Further when the postgres asks me about "001...0082", I do not have that either, since in the intervening minutes, I have moved that file out of my /opt/data/mirror to /opt/data/tape directory for long term tape storage. So how do I make my standby postgres happy? Having run into that situation, the standby also spits out the following: --- LOG: could not open file "pg_xlog/000000010000000000000082" (log file 0, segment 130): No such file or directory LOG: invalid primary checkpoint record LOG: could not open file "pg_xlog/000000010000000000000080" (log file 0, segment 128): No such file or directory LOG: invalid secondary checkpoint record --- What is happening is that the postgres is looking behind in time for the "0001...0082" and "0001...0080" files. The question I have is, how far does it look behind in time? Then I have to be careful of when I move the WAL file out to tape. Further if I know how far back in time I have to keep my WAL file, then I can device an effective strategy of removing older files. That is if I come and say that I generate WAL file every 2 minutes, then do I keep 10 files or 120 files? Any insight on this will help. Regards Dhaval
