Two outages of Exchange Active Sync since November 2021 (Exchange 2016)

Question

Two outages of Exchange Active Sync since November 2021 (Exchange 2016)

MarkusHH 21

Hi there.

Any ideas about the root cause or how to eliminate it?

Error
Alls EAS client devices don't sync anymore.

Workaround
"Restart-WebAppPool MSExchangeSyncAppPool" immediately solved the problem.

Occurance
Never had happened before. Server are restarted at least once a months. First occured on November 23rd and a second time on 14th of December 14th. Hasn't occured since.

Environment
Single server Exchange 2016 organization (last migration from 2010). Non-hybrid.

Analysis

2021:11:23-12:33:08 <firewall> httpd: id="0299" srcip="<...>" localip="<...>" size="0" user="-" host="<...>" method="OPTIONS" statuscode="401" reason="-" extra="-" exceptions="SkipAntiVirus, SkipURLHardening" time="14237" url="/Microsoft-Server-ActiveSync" server="eas.<domain.tld>" port="443" query="?Cmd=Options&User=<domain>%5C<alias>&DeviceId=<...>&DeviceType=Outlook" referer="-" cookie="-" set-cookie="-" websocket_scheme="-" websocket_protocol="-" websocket_key="-" websocket_version="-" uid="<...>"

Thanks and best regards
Markus

KyleXu-MSFT 26,396 Reputation points

2022-01-25T02:53:01.897+00:00

@MarkusHH

It's hard to narrow down issues that only happened in the past. If this issue could be recurrent, it could help us to troubleshoot.

Glad to see this one issue doesn't happen now. It is suggested to keep the Exchange server in the latest version (Exchange 2016 CU 22 + Jan22SU), it could put your Exchange server in a safe state.

About this issue, based on my searching, this issue may be caused by a lack of resources. You could have a check about Event Viewer, whether there exists related event during this issue occurs. If this issue occurs again, you can also check the Task Manager, whether the Exchange is in a high load state.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
KyleXu-MSFT 26,396 Reputation points

2022-01-28T08:16:03.043+00:00

Any update about this thread now? Whether there exists related event on your Exchange server to help us narrow down this one?

1 answer

Your answer

KyleXu-MSFT 26,396 Reputation points

2022-01-25T02:53:01.897+00:00

@MarkusHH

It's hard to narrow down issues that only happened in the past. If this issue could be recurrent, it could help us to troubleshoot.

Glad to see this one issue doesn't happen now. It is suggested to keep the Exchange server in the latest version (Exchange 2016 CU 22 + Jan22SU), it could put your Exchange server in a safe state.

About this issue, based on my searching, this issue may be caused by a lack of resources. You could have a check about Event Viewer, whether there exists related event during this issue occurs. If this issue occurs again, you can also check the Task Manager, whether the Exchange is in a high load state.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
KyleXu-MSFT 26,396 Reputation points

2022-01-28T08:16:03.043+00:00

Any update about this thread now? Whether there exists related event on your Exchange server to help us narrow down this one?

Answer 1

Thanks for your reply.

During the first occurance, the server was at CU22 and therefore behind KB5007409. The second occurance however happend during the server being at that time current patchlevel with CU22+KB5007409.

Since the second occurance it has not occured a third time. Server has already been patched to Jan22SU.

Currently there are no 3007 or 3014, nor do we have a lack of ressources.

However I will check the event log and the ressource consumption data in case the error occurs a third time.

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Two outages of Exchange Active Sync since November 2021 (Exchange 2016)

1 answer

Your answer