On Exchange 2016 servers, the following event is sometimes written to the application log every 30 minutes:
Source: MSExchangeDiagnostics
Event ID: 1006
The performance counter ‚\\EXCHANGE\MSExchange Assistants – Per Database(msexchangemailboxassistants-fwdb)\Event Dispatchers Catching Up‘ sustained a value of ‚2.730,00‘, for the ’30‘ minute(s) interval starting at ‚10.01.2018 19:39:00‘. Threshold breached since ‚25.12.2017 21:09‘. None Trigger Name:EventDispatchersCatchupQueueTrigger. Instance:msexchangemailboxassistants-fwdb
This bug also existed in Exchange 2013. The workaround to prevent the annoying entries in the log still works perfectly.
In the Exchange BIN directory under $exinstall\bin there is a file with the following name:
- Microsoft.Exchange.Diagnostics.Service.exe.config
In this file, the line with the following entry must be changed:
<add Name=“Microsoft.Exchange.Diagnostics.Service.ExchangeJobs.Triggers.EventDispatchersCatchupQueueTrigger“ Assembly=“Microsoft.Exchange.Diagnostics.Service.ExchangeJobs.dll“ Enabled=“True“ Role=“Mailbox“/>
The line is changed as follows (Enabled="false"):
<add Name=“Microsoft.Exchange.Diagnostics.Service.ExchangeJobs.Triggers.EventDispatchersCatchupQueueTrigger“ Assembly=“Microsoft.Exchange.Diagnostics.Service.ExchangeJobs.dll“ Enabled=“false“ Role=“Mailbox“/>
In my case it is line 1440:
After the line has been changed, the "Microsoft Exchange Diagnostics" service must be restarted once.
The error is no longer written to the log.