http://blog.itpub.net/23135684/viewspace-703620/

In this Document
  Symptoms
  Cause
  Solution

Applies to:

Oracle Server - Enterprise Edition - Version: 10.1.0.2 to 10.2.0.5 - Release: 10.1 to 10.2
Information in this document applies to any platform.
***Checked for relevance on 05-APR-2011***

Symptoms

 After real time apply works within 24hrs
the following error occurs.

Checking the standby logs on standby database, all SRLs are ACTIVE dated from weeks ago- normally we see 1 used for 1 thread and the others will be UNASSIGNED

Cause

In Dec1 SRLs created on LG were not archived/stuck and hence remained ACTIVE and could not longer be assigned. At the that time we see that Primary was archiving every minute and only 1 ARCH available to archive to standby. From standby log_archive_max_processes was set to 2, hence only 1 ARCH archiving Locally and most likely unable to cope with the amount of archiving required.

Solution

1. On Standby/Primary set log_archive_max_processes=10

OR

2. Another way around this if the logs have been applied as they have in this case, the old standby logs 
can be dropped and recreated to clear the problem.

<logfile_name><logfile_name>

#########################################################

報錯 ：

Sun Oct 21 04:39:06 CST 2018

FAL[client]: Failed to request gap sequence

GAP - thread 2 sequence 101986-101989

解決方法:

ALTER DATABASE REGISTER LOGFILE '/tmp/dba/1/o1_mf_2_101986_fwps5fbo_.arc';

ALTER DATABASE REGISTER LOGFILE '/tmp/dba/1/o1_mf_2_101988_fwps7ntp_.arc';

ALTER DATABASE REGISTER LOGFILE '/tmp/dba/1/o1_mf_2_101987_fwps7o6j_.arc';

ALTER DATABASE REGISTER LOGFILE '/tmp/dba/1/o1_mf_2_101989_fwpsg14g_.arc';

ALTER DATABASE REGISTER LOGFILE '/tmp/dba/1/o1_mf_2_102004_fwq5wq6m_.arc';

ALTER DATABASE REGISTER LOGFILE '/tmp/dba/1/o1_mf_2_102005_fwq5wx6s_.arc';