SYMPTOMS
You may see a warning alert in MOM Operator Console;
Severity: Warning
Status: New
Source: AD Replication Monitoring
Name: AD Replication is occurring slowly
Description: The following DCs took more than three times the expected replication time to replicate.
Severity: Warning
Status: New
Source: AD Replication Monitoring
Name: AD Replication is occurring slowly
Description: The following DCs took more than three times the expected replication time to replicate.
DESCRIPTION
The following DCs took more than three times the expected replication time to replicate.
Format: DC, Naming Context, Calculated Replication Time (in minutes). Intersite, expected replication time is 15 minutes.
Format: DC, Naming Context, Calculated Replication Time (in minutes). Intersite, expected replication time is 15 minutes.
CAUSE
This is due to IntersiteExpectedMaxLatency of 15 threshold of 15 minutes in AD Replication Monitoring script
WORKAROUND
AD Replication Monitoring script Detects slow replication and replication problems. You can find AD Replication Monitoring VBSscript in the Scripts Container under Management Packs. The parameters can be customized for IntersiteExpectedMaxLatency based on the WAN links for Inter Sites. IntersiteExpectedMaxLatency is the expected maximum time that replication will take to occur between sites and by default it is set to 15 minutes.
DO NOT EDIT THE SCRIPT DIRECTLY and instead click on Parameters – Click on IntersiteExpectedMaxLatency and enter the new value.
What are acceptable values for the change??
We have a small network with 4 sites and 5 DC’s and a fast WAN with low delays.
The rule is fired and coming back with times as high as 57 and 114 minutes. I have not noticed any problems with AD nor are there any errors/warnings logged.
Any inside would be apreciated.
Fred
I think investigation on the destination DC is recommended. Initial DC updates can take long and can be safely ignored. But, when running in a small environment AD replication should be done within 10 minutes, even over a WAN. for latency information.
Investigating the destination DC could give more insight on what’s up than only checking the originating DC.
Things to do at the destination DC:
* Network : Check if RPC calls are arriving at the WAN site 100% without errors.
* Look for Event 1862 events in the Directory Service log
* Run dcdiag or
* Run repadmin /showvector /latency
Good luck!