RFS[3]: No standby redo logfiles available for thread 1

问题描述：备库恢复DG之后，mrp进程一直是wait_for_log，主库创建数据没有正常同步，只有在切换归档的时候备库才能同步主库数据

查看主库日志，主库RFS进程提示没有可用的standby redo在线程1上

主库输出日志：

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RFS[3]: Assigned to RFS process 15362   RFS[3]: No standby redo logfiles available for thread 1   RFS[3]: Opened log for thread 1 sequence 712 dbid 1446616449 branch 1051207668   Sat Apr 24 10:19:52 2021

查询主备库standby_log大小

主库：

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SQL> select group#,thread#,sequence#,bytes/1024/1024 from v$Log;       GROUP#    THREAD#  SEQUENCE# BYTES/1024/1024 ---------- ---------- ---------- ---------------      1      1        709         512      2      1        710         512      3      1        711         512      4      1        712         512      5      1        707         512      6      1        708         512

备库：

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SQL> select group#,thread#,sequence#,bytes/1024/1024 from v$standby_log;       GROUP#    THREAD#  SEQUENCE# BYTES/1024/1024 ---------- ---------- ---------- ---------------     30      1          0         500     31      1          0         500     32      1          0         500     33      1          0         500     34      1          0         500     38      1          0         500     39      1          0         500

经比较主备库standby_log大小创建不一致，重建备库standby_log

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alter database add standby logfile thread 1 group 48'/data/orcl/std_redo48.log' size 512M; alter database add standby logfile thread 1 group 49'/data/orcl/std_redo49.log' size 512M; alter database add standby logfile thread 1 group 40'/data/orcl/std_redo40.log' size 512M; alter database add standby logfile thread 1 group 41'/data/orcl/std_redo41.log' size 512M; alter database add standby logfile thread 1 group 42'/data/orcl/std_redo42.log' size 512M; alter database add standby logfile thread 1 group 43'/data/orcl/std_redo43.log' size 512M; alter database add standby logfile thread 1 group 44'/data/orcl/std_redo44.log' size 512M;     alter database drop logfile group 38; alter database drop logfile group 39; alter database drop logfile group 30; alter database drop logfile group 31; alter database drop logfile group 32; alter database drop logfile group 33; alter database drop logfile group 34;

主库切换归档测试

alter system switch logfile;

备库：

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SQL> select process, status, thread#,sequence#, block#, blocks from v$managed_standby;   PROCESS   STATUS      THREAD#  SEQUENCE#     BLOCK#     BLOCKS --------- ------------ ---------- ---------- ---------- ---------- ARCH      CONNECTED     0      0          0      0 ARCH      CONNECTED     0      0          0      0 ARCH      CONNECTED     0      0          0      0 ARCH      CLOSING       1    710          1        416 RFS   IDLE          0      0          0      0 MRP0      APPLYING_LOG      1    713     255005    1048576 RFS   IDLE          0      0          0      0 RFS   IDLE          1    713     255005      1   8 rows selected.

状态正常，mrp进程已经变成applying_log