Pls help: delay with Nagle's algorithm
We're running 9.3 on a pair of LTM 6400. We've virtual servers for LDAPS (using LTM's SSL acceleration) and LDAP traffic.
A user complained one of their jobs that issues 100K LDAP queries runs ~10 times longer than expected. After some studies, we found that performance resumes normal if:
- we switch the user job to use LDAPS virtual server on the 6400 !
- bypass LTM and talk to backend LDAP servers directly
- turn off Nagle's algorithm in tcp profile used by the LDAP and LDAPS virtual servers.
Performance of single LDAP query to LDAP virtual server is of order 0.1ms while that for LDAPS virtual server is of order 0.01ms.
Although the issue is resolved by defining a customized tcp profile with Nagle's Algorithm disabled, I wonder why when Nagle's Algorithm is enabled, there is no impact on performance for SSL accelerated virtual server (I expect both LDAP/LDAPS experience the same delay).
Would anyone please help? Thanks a lot.
Rgds,
/ST Wong