Hi guys,

We have set up 4 Exchange 2013 Servers (multi-role) in a DAG, where one of these are a lagged one.

We use HLB to distribute clients to server 1-3. The forth one should only be used in disaster recovery.

If we initiate a database switchover, our Outlook 2010 clients gets disconnected for 2-3 secs.

If we initiate a server reboot where an active database is hosted and the clients gets disconnected for 1:30-2 minutes.

If we change the hostfile on the client and connect to server3 and we initiate a server reboot, the database gets dismounted on server01 and mounted on server02 in just a few secs but the outlook-client is still disconnected for about 2 minutes.

If I look at Outlook connection status the proxyserverlist is empty and the status is saying connecting...

And after about 2 minutes we can see that the proxy serverlist get the mail.company.com name listed

Any ideas why this is so slow? Is this Outlook related or is it something with Exchange config? If we use HLB or if we connect through a exchange server directly we get the same result so we don't think this is HLB related.

Hello,

Usually, outlook needs to reconnect to an active server and the time it takes is usually between 10 and 30 seconds.

For your description, the outlook connect to your server slowly. I recommend you use network monitor to monitor your network.

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Hi, thx for your reply.

So even if my outlook client (using a hostfile) is connected to lets say exchange04 and that server proxies the request towards the mailbox that is hosted on the active database on exchange01.

if exchange01 restarts and the database is active on exchange02. my outlook should be disconnected and then try to re-establish the connection to the mailbox on exchange02 via the echange04 proxy.

howcome this works perfect if I do a database switchover. the outlook is disconnected for 2-5 secs...

Hello,

Why don't you add server04 to HLB?

Since your four servers are in a DAG, I recommend you add server04 to HLB to realize a much better user experience.

Here is the article for your reference.

http://exchangeserverpro.com/exchange-2013-client-access-server-high-availability/

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I have read that article many times but that doesnt help me understand my slow outlook reconnects.

I only use the 4rth server for lagged databases... the other 3 multirole servers should be well enough for 8000 mailboxes.

Hello,

Sorry for delayed response.

Did you use network monitor to monitor your network?

Hello,

Please post the result from tcpview and wireshark.

Hmm, not sure what to post from these apps...

So we have a HLB that was set up to offload the SSL. Exchange was set to "Allow SSL offload".

We tried to disable the SSL offload on the HLB and cleared the "Allow SSL offload" on the Exchange servers. We did IIS reset afterwards.

Still Outlook is disconnected for about 2 minutes 10 sec.

If we do the servershutdown again and restart outlook about 40 sec into the failure it still takes another 60 sec for it to reconnect.

It seems Exchange doesn't allow/accept new client sessions or something even tough the database has been mounted on another server (just after 4-5 secs).

• Edited by [fredrik] Friday, October 25, 2013 6:44 AM

Hi again, is this a problem or is this by design?

- A database switchover takes 3-4 sec for outlook to disconnect and reconnect

- A server reboot (all databases mounts on another sever within the DAG) takes around 2 minutes for outlook to disconnect and reconnect

It might be normal?

Hello,

There is not related article to explain outlook takes around 2 minutes to reconnect mailbox.

If you initiates a server switchover, it will initiate database switchovers for each of the active databases on the current server at first.

Please refer to the "server failovers" section in the following article:

http://technet.microsoft.com/en-us/library/dd298067(v=exchg.141).aspx

Hi, didn't understand your first line there. There is "not" related?

On the serverfailure steps, on the bottom of that page it says on nr 9,

"When the database is mountable, the Active Manager on the servers mounts the databases."

This takes about 5-6 secs since I can see that the database gets mounted on another server.

How come outlook takes another 2 minutes to understand that? or get allowed to reconnect?

And this article is about Exchange 2010, is all content related to Exchange 2013 as well?

• Edited by [fredrik] Friday, October 25, 2013 8:49 AM

Hello,

Sorry for delayed response.

I don't find official article or blog to verify outlook takes around 2 minutes to reconnect mailbox when server failover occurs.

Since there is no related error, we may need more time to do some research.

In order to solve your issue and get more ideas, you can contact microsoft support.

http://support.microsoft.com/?ln=en-us