Performance problems when huge number of portal aliases is in use

[mikebigun]

Description of bug

Customer complains about huge performance degradation when around ~5K portals/aliases is in use with a combination of ~2K requests executed at the same time. Whole system becomes very slow and sometimes is coming up to an unresponsive state.
Tracing the system customer identified the problem on a web server. Using various tools identified that many threads are locked out due to very low capability to validate portal aliases during the incoming requests.

Steps to reproduce

Issue is reproducible having following database characteristics:
440k users
500k files
4885 portal alias
2000+ portals
Also, need to simulate 2K+ requests to see the problem.

Current result

System is extremely slow.

Expected result

Need to improve performance.

Affected version

• 9.2.2
• 9.2.1
• 9.2
• 9.1.1
• 9.1
• 9.0