Skip to Main Content
Forums

Oracle Database Discussions

Announcement

For appeals, questions and feedback about Oracle Forums, please email oracle-forums-moderators_us@oracle.com. Technical questions should be asked in the appropriate category. Thank you!

log file sync and block recovery from logseq

User_96XRQNov 5 2020

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.

Comments

Answer

What platform are you on? What are the permissions for the keyfile and directory containing the keyfile? In particular, are the file/directory permission set to permit only the current user to read them? Our new library defaults to enforcing the recommended SSH security practice of having keyfiles be readable by only the current user.

Marked as Answer by Robert Schaefer · Jan 2 2020
3 people found this helpful
Robert Schaefer

Hi John,

i'm running SQL Developer on MacOS 10.15.2. The file permission for the private key is limited to "rw-------" (600). But the directory (".ssh") containing the keys has a lower permission level with "rwxr-xr-x". I limited it to "rwx------" and now the SSH Connections in SQL Developer are working again! Great support, thank you!

1 person found this helpful

I'm glad that you were able to solve your issue. The lack of proper feedback with our new SSH library is something I am looking into. In a future release I hope to provide detailed information when we run into a configuration issue.

2 people found this helpful
YujiSoftware

I had the same problem in my environment.
(SQLDeveloper version 21.2.1.204, build 204.1703)

After investigating the cause, I found that it was a bug in Apache Mina SSHD 2.6.0.
https://issues.apache.org/jira/browse/SSHD-1105
(I've confirmed that this fix solves the problem)

This bug has been fixed in sshd-2.7.0.

I want you to update the version of sshd included in SQLDeveloper.

John McGinnis-Oracle

Thanks for the update. Can you test in your environment with our 21.4.3 release? We updated to sshd-2.7.0 in that release, so hopefully it works out of the box.

1 person found this helpful
YujiSoftware

Thank you for your comment.
After upgrading, it worked fine!
(SQL Developer version 21.4.3.063, build 063.0100)

The Japanese page is still 21.2.1, so I'd be happy if you could update it.
https://www.oracle.com/jp/tools/downloads/sqldev-downloads.html

1 - 6

Post Details

Added on Nov 5 2020
#11gr2, #general-database-discussions, #performance, #tuning
3 comments
643 views