I have been getting this issue multiple times in my working life and I always forgot to put this up in the blog for future reference. Since, I’m getting this once again while troubleshooting an issue for a client, I decided to put this up.
There are multiple reason why your EMC loading very slowing
Your server is having a performance issue
This may sound obvious but sometimes system admins tends to look at only CPU and memory not disk I/O. Check the resource monitor and see which resource are bottlenecked. You might be surprised that AV or backup is running in the background.
Solution: paused or stop those resource hogging or use EMS.
EMC tries to connect to the certificate revocation list (CRL) Web site.
Exchange examines the CRL list to verify the code signing certificate. Since its connecting to the internet, most probably it’s using some of the IE components which we can control.
Solution: Turn off (Uncheck) “Check for publisher’s certificate revocation” & “Check for server certificate revocation” options on the server/workstations you are starting the EMC (Exchange Management Console) on. (ref)
Note: Proceed with cautions This is a security option and unchecking this represent a risk unless the machine is in a secure environment, please be aware the of consciences of this change.
- In Windows Internet Explorer –> Tools –> Internet Options –> Advanced tab
- In the Security section, uncheck the below two options “Check for publisher’s certificate revocation” & “Check for server certificate revocation”
EnableTCPA is enabled
I haven’t had any situation which requires me to disable this setting. Richard Roddy in his Technet article, wrote that if you disable the TCPChimney and RSS, you will to also disbale TCPA. Here is the excerpt of this article.
After much troubleshooting by our Directory Services team, including debug tracing of the AD processes, etc., that showed that AD performance was just fine, it was finally found that the problem was due to the EnableTCPA setting under HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters. The value was set to 1, enabling the feature, while the other Scalable Networking Pack (SNP) features (EnableTCPChimney, EnableRSS) were disabled.
According to the Windows Networking team this combination can cause the TCP driver on that machine to think that the sender has reduced its sending capacity. The TCP driver then begins to perform regular jobs in response to the low sending capacity, rather than just immediately responding to the requests. This behavior causes the slow response/pauses that we could see in the network traces. However, the fact that the TCP driver is waiting to send the outgoing packets is something that cannot be seen.
The solution: disable the feature by setting EnableTCPA to 0.
You can read the whole article here
Personal note: I’ve always prefer to use Exchange Management Shell (EMS) since it is faster and it provides more options whether for reporting, troubleshooting, configuring or day-to-day management. I think it’s worth for a new or existing Exchange admin to invest some of his/her time learning PowerShell 😉