nslcd timer expired errors and server pauses - RHEL6

Issue

RHEL 6 x86_64 running on physical hardware with IBM Tivoli Storage Manager Server (TSM) installed and running. Symptoms are:

• Noticeable pauses in server
• Long running operations and authentication timeouts to TSM
• /var/log/messages errors get logged:

Nov 20 08:39:29 hostname1 nslcd[5256]: [3d224f] error reading from client: Timer expired
Nov 20 08:39:49 hostname1 nslcd[5256]: [78fa39] error reading from client: Timer expired
Nov 20 08:40:09 hostname1 nslcd[5256]: [2dc63b] error reading from client: Timer expired
Nov 20 08:40:29 hostname1 nslcd[5256]: [5775d6] error reading from client: Timer expired
Nov 20 08:40:49 hostname1 nslcd[5256]: [efb8ba] error reading from client: Timer expired
Nov 20 08:41:09 hostname1 nslcd[5256]: [a6ad6f] error reading from client: Timer expired
Nov 20 08:41:29 hostname1 nslcd[5256]: [b78064] error reading from client: Timer expired
Nov 20 08:41:49 hostname1 nslcd[5256]: [cad3be] error reading from client: Timer expired

• This impacts backup and server operations, slowing them to a crawl.
• This issue can occur without TSM if nslcd passes select() the fd_set more than 1024.