流复制失败，因为"WAL段已被移动“

Question

我试图在Postgres 11.5上实现主/从流复制。我跑了以下步骤-

论大师

select pg_start_backup('replication-setup',true);

奴隶停止postgres 11数据库并运行

rsync -aHAXxv --numeric-ids --progress -e "ssh -T -o Compression=no -x" --exclude pg_wal --exclude postgresql.pid --exclude pg_log MASTER:/var/lib/postgresql/11/main/* /var/lib/postgresql/11/main

论大师

select pg_stop_backup();

奴隶论

rsync -aHAXxv --numeric-ids --progress -e "ssh -T -o Compression=no -x"  MASTER:/var/lib/postgresql/11/main/pg_wal/* /var/lib/postgresql/11/main/pg_wal

我在从文件夹~/11/主文件夹上创建了recovery.conf文件

standby_mode = 'on'
primary_conninfo = 'user=postgres host=MASTER port=5432 sslmode=prefer sslcompression=1 krbsrvname=postgres'
primary_slot_name='my_repl_slot'

当我在奴隶上启动Postgres时，我会得到主程序和从日志上的错误-

019-11-08 09:03:51.205 CST [27633] LOG:  00000: database system was interrupted; last known up at 2019-11-08 02:53:04 CST
2019-11-08 09:03:51.205 CST [27633] LOCATION:  StartupXLOG, xlog.c:6388
2019-11-08 09:03:51.252 CST [27633] LOG:  00000: entering standby mode
2019-11-08 09:03:51.252 CST [27633] LOCATION:  StartupXLOG, xlog.c:6443
2019-11-08 09:03:51.384 CST [27634] LOG:  00000: started streaming WAL from primary at 12DB/C000000 on timeline 1
2019-11-08 09:03:51.384 CST [27634] LOCATION:  WalReceiverMain, walreceiver.c:383
2019-11-08 09:03:51.384 CST [27634] FATAL:  XX000: could not receive data from WAL stream: ERROR:  requested WAL segment 00000001000012DB0000000C has already been removed
2019-11-08 09:03:51.384 CST [27634] LOCATION:  libpqrcv_receive, libpqwalreceiver.c:772
2019-11-08 09:03:51.408 CST [27635] LOG:  00000: started streaming WAL from primary at 12DB/C000000 on timeline 1
2019-11-08 09:03:51.408 CST [27635] LOCATION:  WalReceiverMain, walreceiver.c:383

问题是，WAL - 00000001000012DB0000000C在运行pg_stop_backup()之前是可用的，并且一旦执行pg_stop_backup()，就会被归档，不再可用。因此，这并不是WAL由于WAL_KEEP_SEGMENTS低而被归档的问题。

postgres@SLAVE:~/11/main/pg_wal$ cat 00000001000012DB0000000C.00000718.backup
START WAL LOCATION: 12DB/C000718 (file 00000001000012DB0000000C)
STOP WAL LOCATION: 12DB/F4C30720 (file 00000001000012DB000000F4)
CHECKPOINT LOCATION: 12DB/C000750
BACKUP METHOD: pg_start_backup
BACKUP FROM: master
START TIME: 2019-11-07 15:47:26 CST
LABEL: replication-setup-mdurbha
START TIMELINE: 1
STOP TIME: 2019-11-08 08:48:35 CST
STOP TIMELINE: 1

我的主人有archive_command集，我有丢失的WALs可用。我将它们复制到从服务器上的还原目录中，并尝试了下面的recovery.conf，但是它仍然失败，因为主服务器报告了相同的WAL segment has already been moved错误。

知道我能怎么解决这个问题吗？过去，我在Postgres 9.6上使用rsync安装复制，没有任何问题，但是在Postgres 11上经历了这个问题。

standby_mode = 'on'
primary_conninfo = 'user=postgres host=MASTER port=5432 sslmode=prefer sslcompression=1 krbsrvname=postgres'
restore_command='cp /var/lib/postgresql/restore/%f %p'

Answer 1

将一个restore_command放入recovery.conf中，可以恢复归档的WAL文件，您就没事了。