Oracle DataGuard容灾出现FAL Message In Alert.log When No Gap In Standby

Applies to: Oracle Server - Enterprise Edition - Version: 10.1.0.2 to 10.2.0.3 - Release: 10.1 to 10.2
Information in this document applies to any platform.
***Checked for relevance on 25-MAR-2011***
SymptomsWhen using ARCH transport, gaps could be flagged in the alert log even though the single log gap was for a log that had not been written at the primary yet.

alert.log on primary shows:

[font=NSimsun]FAL[server]: Fail to queue the whole FAL gap
GAP - thread 1 sequence 63962-63962
DBID 1243807152 branch 631898097

or alert.log on standby shows:

v$archive_gap re
[font=NSimsun]Fetching gap sequence in thread 1, gap sequence 63962-63962
Thu Jan 24 14:36:30 2008
FAL[client]: Failed to request gap sequence
GAP - thread 1 sequence 63962-63962
DBID 2004523329 branch 594300676
FAL[client]: All defined FAL servers have been attempted.
turns no rows

[font=NSimsun]SQL> select * from v$archive_gap;
no rows selected

CauseBug 5526409 - FAL gaps reported at standby for log not yet written at primary
SolutionThis is a known Bug 5526409 which is fixed in 10.2.0.4 and 11.1.

To solve the issue, please upgrade to the newest patchset since Bug 5526409 is fixed in 10.2.0.4.
Their is no impact of these messages on the database. You can safely ignore these messages.

Furthermore there are One-off Patch for Bug 5526409 on top of 10.2.0.3 available for some platforms. Please check Patches & Updates within My Oracle Support MOS.

ReferencesBUG:5526409 - FAL[CLIENT]: FAILED TO REQUEST GAP SEQUENCE BUT NO GAPS FOUND
PATCH:5526409 - FAL[CLIENT]: FAILED TO REQUEST GAP SEQUENCE BUT NO GAPS FOUND