Skip to Main Content
Forums

Database Software

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!

Interested in getting your voice heard by members of the Developer Marketing team at Oracle? Check out this post for AppDev or this post for AI focus group information.

Regular "ORA-16857: standby disconnected from redo source for longer than specified threshold"...

1007321Apr 7 2014 — edited Apr 16 2014

Hi,

Just completed DataGuard configuration between 2 11gR2 RAC primary/standby databases.

I made a few tests (created a table as select * from dba_directories to get a few rows on the

primary), my data is not replicated to the standby (opened in 'READ ONLY WITH APPLY' mode)...

From within DGMGRL utility I get the following error, on a regular basis:

DGMGRL> show configuration

Configuration - dgtestfo

  Protection Mode: MaxPerformance

  Databases:

    testfo  - Primary database

    testfos - Physical standby database

      Warning: ORA-16857: standby disconnected from redo source for longer than specified threshold

Fast-Start Failover: DISABLED

Configuration Status:

WARNING


and then the next second I run this command:

DGMGRL> show configuration

Configuration - dgtestfo

  Protection Mode: MaxPerformance

  Databases:

    testfo  - Primary database

    testfos - Physical standby database


Fast-Start Failover: DISABLED

Configuration Status:

SUCCESS

this error disappears for a few seconds; then if I retype 'show configuration' it pops up again, and so on...

Where would you go to investigate this ? I made all checks possible, without success.

Thanks a lot.

Regards,

Seb

Comments

mseberg

Hello;

Try setting TransportDisconnectedThreshold higher than the default of 30.

DGMGRL> EDIT DATABASE testfo SET PROPERTY TransportDisconnectedThreshold='120';

Best Regards

mseberg

BPeaslandDBA

I would start by looking in two logs...the standby's alert log and the DG Broker log. The DG Broker log can be found in the same directory as your alert log and normally has a file named drcinstance_name.log. See if there are messages in either of those on the standby side around the time you are getting this error. Since your standby is RAC, check all instances logs.

HTH,
Brian

1007321

Well, I had a look at these files of course... The standby alert.log shows nothing; as to

the Dataguard log it appends every X minutes the following:

Data Guard Broker Status Summary:

  Type                        Name                             Severity  Status

  Configuration               dgtestfo                          Warning  ORA-16608

  Primary Database            testfo                            Success  ORA-00000

  Physical Standby Database   testfos                           Warning  ORA-16857

which is the same error as that shown in DGMGRL, with no further detail whatsoever...

teits

issue has to do with network between primary and standby DB site.

probably your network latency is very bad OR intermittent failures occurs on your network.

a workaround is to increase  TransportDisconnectedThreshold database property:

DGMGRL> EDIT DATABASE testfo SET PROPERTY TransportDisconnectedThreshold='120';


Tobi

Tobi's Oracle DBA & UNIX Blog

Renu-Oracle

The 'TransportDisconnectedThreshold' is related to the connection to the Primary
There is another new parameter, related to the gap : TransportLagThreshold


Thanks

user10341747

Please check this out:

ORA-16857: standby disconnected from redo source for longer than specified threshold

Error code: ORA-16857

Description: standby disconnected from redo source for longer than specified threshold

Cause:
The amount of time the standby was disconnected from the redo source database exceeded the value specified by the 'TransportDisconnectedThreshold' database property. It is caused by no network connectivity between the redo source and the standby databases.

Action:

Ensure that there is network connectivity between the redo source and standby databases, and the redo source is working properly.

The above error is just a warning message and not actually a problem with the standby database. The error is received when the last communication from the primary database exceeds the value specified by 'TransportDisconnectedThreshold' property. The value is in seconds. Default value is 30 seconds


SOLUTION - Setting 'TransportDisconnectedThreshold' to 0 seconds will disable the alert. Alternatively we can set the property to a higher value.
1 - 6
Locked Post
New comments cannot be posted to this locked post.

Post Details

Locked on May 14 2014
Added on Apr 7 2014
#data, #data-guard, #not, #performance-availability
6 comments
66,189 views