We have some https sites (aspx, asmx) hosted on Windows Server 2012 R2 with IIS 8.5 (Platform – AWS lightsail )
The Server specifications are as follows
CPU: E5-2676 v3 @ 2.40 GHz
RAM: 8GBWe had a problem lately where the lsass.exe would consume all the CPU making the total CPU to spike. We found lsass.exe is used for Authentications and incase of Server with IIS , https requests require use of this component. Some Extra info are added in the question asked previously here Opens a new window
where it is mentioned that Lsass.exe process is not used in the IIS 7.0 IIS for SSL. But while testing HTTPS connections using Jmeter tool (users: 1000, ramp up period: 10 ) we see that lsass.exe CPU usage increases to about 26 % for a brief time even on IIS 8.5 ( assuming IIS 8 and above also is same as IIS 7 under the hood) .
Our guess is that IIS 8.5 still uses lsass.exe while handling Https requests. One solution that we want to do right now is to increase the Servers instance specs to compensate the high CPU usage required by lsass.exe
What we have tried:
- We have tested the Https aspx site hosted in IIS 8.5 on Windows Server 2012 R2 using Jmeter tool. The lsass.exe takes about 26%.
- We have tested the same Https aspx site hosted in IIS 10 on Windows Server 2019 using Jmeter tool. The lsass.exe results are the same. ( Same instance hardware specs)
- Tried Https site hosted in apache. Lsass.exe is not used.
But we are not able to determine the CPU sizing required to handle the HTTPS requests. Because this 26% of usage can be lowered when using a Higher capacity CPU , how to determine which one. Can you guys help with this .
- Is it normal CPU value that lsass.exe is consuming in our case for the tested Workload?
- Is there any way to calculate the CPU usage in percent for any CPU on per app basis before hand?