Exchange EWS Performance issues periodically RRS feed

  • Question

  • Hi,

    We have two Exchange servers 2013. We have some applications using web services Exchange (EWS Managed API) and are installed in other servers.
    A few times (three times daily), EWS calls become slow, e.g. FindItems method takes more than 40s.
    Delays are a few minutes and then everything returns to normal.
    Among the EWS applications, we have a service that monitors about 800 calendars with EWS push notification.
    I set up performance counters on all Exchanges servers, there is one of IIS w3wp process ramping up every 2 hours.

    Any ideas about this "performance issue" please?


    Tuesday, April 5, 2016 5:24 PM

All replies

  • Check the EWSLog on the CAS server and try to use that to correlate that with the time your having problems, is it happening at the same times every day or random times is the environment virtualized ?. If its the same time you need to look at your environment eg updates, Scheduled tasks, snapshots etc.


    Wednesday, April 6, 2016 4:09 AM
  • Hi Glen,

    Is that EWS queries are running on the CAS or Exchange servers?
    My environment is virtualized and the problem does not occur at the same time each day.
    I tried to analyze the EWS logs on the CAS server, but there are many performance counters and I do not know which counters I have to analyze it. That is why I have set up a data collector with a minimum counters.

    I have traces of yesterday on the CAS server and the next graph shows that the application pool MSExchangeServicesAppPool ramping up during the period when I have slowness and reached 44,000 active queries.

    Is that normal to see 44,000 active queries?

    Other counters seem normal because I do not see a ramp-up during this period.

    Have you any idea about default Scheduled tasks on Exchnage and CAS servers?



    Wednesday, April 6, 2016 8:48 AM
  • I think Glen meant the EWSLog located in \Program Files\Microsoft\Exchange Server\V15\Logging\Ews.

    there you can see what happens with EWS in these "special moments " when it becomes slow. :)


    Gregor Stefka


    Businessprocessautomation with the EWS SQL Interface SQLExchangeSync

    EDIT: I have missed the other log directory: Program Files\Microsoft\Exchange Server\V15\Logging\HttpProxy\Ews  

    Wednesday, April 6, 2016 8:55 AM
  • >>Is that EWS queries are running on the CAS or Exchange servers?

    All the client access requests EWS, Mapi, OWA etc on 2013 will go through the CAS

    As Gregor  mentioned you want to look at the access logs (maybe include the OWA logs as well), sounds like a rouge application you have hitting your sever if you check the access logs have a look at why you have so many active requests coming in at the time you see a spike in the Appool.

    Other things to look at maybe an Anti virus scanner that is scanning the store I would check the CAS server Windows event logs as well for any time correlated errors. If non of that help you can try ExMon on the server to watch more what's happening at the Exchange level when the issue occurs.


    Thursday, April 7, 2016 4:50 AM
  • Anti Virus is a very good idea. I am still wondering if its the intended and right way that the AntiVirus companies use EWS to do their scans (from Microsofts perspective). That said, i also see a lot of "traffic" on customer sites in the EWSlogs that originates from Exchange-AntiVirus-Solutions these days....


    Gregor Stefka


    Businessprocessautomation with the EWS SQL Interface SQLExchangeSync

    Thursday, April 7, 2016 8:55 AM