流式复制因“WAL 段已被移动”而失败

Question

我正在尝试在Postgres 11.5 上实现主/从流复制。我运行了以下步骤 -

在主上

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

在奴隶 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

主控

select pg_stop_backup();

在奴隶上

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 slave ~/11/main 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 Slave 上启动 Postgres 时，我在 MASTER 和 SLAVE 日志上都收到错误 -

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 START WAL - 00000001000012DB0000000C 在我运行 pg_stop_backup() 之前一直可用，并且在执行 pg_stop_backup() 后被归档并且不再可用。因此，这不是由于WAL_KEEP_SEGMENTS 低而导致 WAL 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 MASTER 设置了 archive_command，并且我有缺少的 WAL 可用。我将它们复制到 SLAVE 上的还原目录并尝试了下面的 recovery.conf，但仍然失败，MASTER 报告相同的 WAL segment has already been moved 错误。
知道如何解决这个问题吗？我过去在 Postgres 9.6 上使用 rsync 设置复制没有任何问题，但在 Postgres 11 上遇到了这个问题。

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restore_command 放入recovery.conf 可以恢复归档的WAL 文件，就可以了。