问题现象：DG搭建完成后，主库归档不能自动同步到备库。

问题排查：主库告警日志报错：

PING[ARC2]:Heartbeatfailedtoconnecttostandby'cjcdb02'.Erroris16058.

报错原因：备库故障，主库无法连接备库，备库恢复后，主库没有尝试重连备库。

解决方案：主库重新激活log_archive_dest_state_2

过程如下：

主库：

切换归档

SQL>altersystemswitchlogfile;Systemaltered.SQL>archiveloglist;DatabaselogmodeArchiveModeAutomaticarchivalEnabledArchivedestination/archOldestonlinelogsequence15Nextlogsequencetoarchive17Currentlogsequence17

备库：

没有接收到归档日志

SQL>archiveloglist;DatabaselogmodeArchiveModeAutomaticarchivalEnabledArchivedestination/archOldestonlinelogsequence0Nextlogsequencetoarchive0Currentlogsequence0

查看备库告警日志，没有报错，RFS进程已经启动

RFS connections are allowed

主库：

主库告警日志：

UsethefollowingSQLcommandsonthestandbydatabasetocreatestandbyredologfilesthatmatchtheprimarydatabase:ALTERDATABASEADDSTANDBYLOGFILE'srl1.f'SIZE52428800;ALTERDATABASEADDSTANDBYLOGFILE'srl2.f'SIZE52428800;ALTERDATABASEADDSTANDBYLOGFILE'srl3.f'SIZE52428800;ALTERDATABASEADDSTANDBYLOGFILE'srl4.f'SIZE52428800;TueAug0415:29:262020ALTERSYSTEMSETlog_archive_dest_state_2='ENABLE'SCOPE=MEMORYSID='*';TueAug0415:29:262020PING[ARC2]:Heartbeatfailedtoconnecttostandby'cjcdb02'.Erroris16058.TueAug0415:29:282020

主库连接一次备库失败后，没有尝试重连。

主库：

重新激活

SQL>altersystemsetlog_archive_dest_state_2=defer;SQL>altersystemsetlog_archive_dest_state_2=enable;

主库告警日志：

TueAug0415:33:582020ALTERSYSTEMSETlog_archive_dest_state_2='DEFER'SCOPE=BOTH;TueAug0415:34:222020ALTERSYSTEMSETlog_archive_dest_state_2='ENABLE'SCOPE=BOTH;TueAug0415:34:222020Thread1cannotallocatenewlog,sequence20CheckpointnotcompleteCurrentlog#1seq#19mem#0:/oracle/oradata/cjcdb01/redo01.logThread1cannotallocatenewlog,sequence20PrivatestrandflushnotcompleteCurrentlog#1seq#19mem#0:/oracle/oradata/cjcdb01/redo01.logThread1advancedtologsequence20(LGWRswitch)Currentlog#2seq#20mem#0:/oracle/oradata/cjcdb01/redo02.logTueAug0415:34:292020ArchivedLogentry17addedforthread1sequence19ID0x3995c964dest1:TueAug0415:34:292020ARC0:Standbyredologfileselectedforthread1sequence19fordestinationLOG_ARCHIVE_DEST_2TueAug0415:34:292020******************************************************************LGWR:Setting'active'archivalfordestinationLOG_ARCHIVE_DEST_2******************************************************************LNS:Standbyredologfileselectedforthread1sequence20fordestinationLOG_ARCHIVE_DEST_2

备库告警日志：

TueAug0415:34:212020RFS[1]:AssignedtoRFSprocess11502RFS[1]:Openedlogforthread1sequence14dbid966115684branch1047470758TueAug0415:34:212020RFS[2]:AssignedtoRFSprocess11504RFS[2]:Openedlogforthread1sequence16dbid966115684branch1047470758TueAug0415:34:212020RFS[3]:AssignedtoRFSprocess11506RFS[3]:Openedlogforthread1sequence15dbid966115684branch1047470758ArchivedLogentry1addedforthread1sequence14rlc1047470758ID0x3995c964dest2:RFS[1]:Openedlogforthread1sequence17dbid966115684branch1047470758ArchivedLogentry2addedforthread1sequence16rlc1047470758ID0x3995c964dest2:ArchivedLogentry3addedforthread1sequence17rlc1047470758ID0x3995c964dest2:ArchivedLogentry4addedforthread1sequence15rlc1047470758ID0x3995c964dest2:RFS[2]:Openedlogforthread1sequence18dbid966115684branch1047470758ArchivedLogentry5addedforthread1sequence18rlc1047470758ID0x3995c964dest2:RFS[2]:Selectedlog4forthread1sequence19dbid966115684branch1047470758TueAug0415:34:282020ArchivedLogentry6addedforthread1sequence19ID0x3995c964dest1:TueAug0415:34:282020PrimarydatabaseisinMAXIMUMPERFORMANCEmodeRFS[4]:AssignedtoRFSprocess11514RFS[4]:Selectedlog4forthread1sequence20dbid966115684branch1047470758

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