Hi all,
sometimes log file sync event spike on our 11.2.0.4 db on Solaris.
when we look at alert log at the same time we see following messages.
Block recovery from logseq 1462532, block 36595759 to scn 3522018885687
Recovery of Online Redo Log: Thread 1 Group 59 Seq 1462532 Reading mem 0
Mem# 0: +REDO/DBNAME/onlinelog/group_59.272.1047579261
Mem# 1: +REDO/DBNAME/onlinelog/group_59.356.1047581307
Block recovery completed at rba 1462532.36596324.16, scn 820.145702968
Block recovery from logseq 1462532, block 36594513 to scn 3522018885686
Recovery of Online Redo Log: Thread 1 Group 59 Seq 1462532 Reading mem 0
Mem# 0: +REDO/DBNAME/onlinelog/group_59.272.1047579261
Mem# 1: +REDO/DBNAME/onlinelog/group_59.356.1047581307
Block recovery completed at rba 1462532.36596324.16, scn 820.145702967
there is no message on lgwr trace and wait chains are below.
%This SECONDS AAS WAIT_CHAIN
------ ---------- ------- --------------------------------------------------------
32% 2985 96.3 -> log file sync -> LGWR wait for redo copy -> ON CPU
26% 2421 78.1 -> ON CPU
21% 1911 61.6 -> log file sync -> log file parallel write
Do you have reason for that?
Regards.