I used this command to set up a streaming replica and it worked perfectly. I tried to run it to create an online backup of the master on that replica for backup purposes and it seems not to have worked as well.
I thought that streaming the WAL would eliminate the need to keep tons of WAL around, that since they were streamed concurrently with the file they would be in place. However, I got pg_basebackup: could not get transaction log end position from server: ERROR: requested WAL segment 000000010000496F000000BF has already been removed The ...backup file in the archive logs folder of the master looks like this" # cat 000000010000496F000000BF.00578DF8.backup START WAL LOCATION: 496F/BF578DF8 (file 000000010000496F000000BF) STOP WAL LOCATION: 4971/11FC6528 (file 000000010000497100000011) CHECKPOINT LOCATION: 496F/C1ACE0D8 BACKUP METHOD: streamed BACKUP FROM: master START TIME: 2017-04-21 01:08:38 PDT LABEL: full-20170421 STOP TIME: 2017-04-21 06:31:28 PDT so the "...already been removed" message is referring to the very first file. The files were definitely being streamed, I restarted and on the master I see this: [root@db20 ~]# ps aux | grep stream postgres 113855 0.4 0.0 274955352 2932 ? Ss 10:53 0:00 postgres: wal sender process postgres 192.168.4.21(51292) streaming 4972/7FBC22B8 root 115958 0.0 0.0 112652 956 pts/2 S+ 10:56 0:00 grep --color=auto stream postgres 142072 0.3 0.0 274955348 3160 ? Ss Apr20 3:47 postgres: wal sender process postgres 192.168.4.21(51240) streaming 4972/7FBC22B8 although the --verbose output from pg_basebackup mentions starting the streaming, it doesn't mention the file names like it does for the datadir files. Am I misunderstanding how this works? I have WAL archiving set up, so the files are available, but I wanted them included in the backup. Thanks! - Ian
