Just wanted to start a discussion about the back end web services on Exchange 2013 MBX servers.

So in Exchange 2013 the CAS proxies the request to the back end for web services, I can then monitor my cas servers web services /healthcheck.htm page etc to decide when to and not to direct traffic to a particular CAS server.

HOWEVER in exchange 2013 if my mailbox is homed on MBX1 which has a problem with IIS or the autodiscover site on IIS my high availability solution does not cater for this as I have no choice over traffic as the CAS directs traffic here for my mailbox correct?

Is this not a big flaw in high availability for Exchange 2013?

1 web service or IIS site failing on 1 mailbox server stops these users from working, CAS failover makes no difference and DAG will not fail the database over eit

Hi,

You can configure DAG for Mailbox high availability in Exchange server 2013. In addition to providing high availability within a datacenter, a DAG can also be extended to one or more datacenters in a configuration that provides site resilience for one or multiple datacenters.

For more information about high availability for mailbox server, here is an article for your reference.

Database availability groups

https://technet.microsoft.com/en-us/library/dd979799%28v=exchg.150%29.aspx?f=255&MSPPError=-2147217396

Hope this can be helpful to you.

Best regards,

This is not what I am talking about, you are talking about server failure of a DAG member, I am talking about the IIS sites failing on a DAG member i.e. the EWS website has a problem on a MBX server this is not automatically failed over!