MySQL Error: Can't create a new thread (errno 11); if you are not out of available memory

Recently I have met a big trouble in one of my newly migrated server.When ever mysql reached 1005 connections it throws a below error,

mysql error: Can't create a new thread (errno 11); 

if you are not out of available memory, you can consult the manual

for a possible OS-dependent bug 

So I have checked the mysql max_connections,open_file_limit and ulimit.Everything looks fine But still i got the same error.I was googled  and found a solution for it.This error depend upon OS not from MySQL.

So when I checked my  max user processor and open files by using ulimit -a I have seen these two variable has 1024 only so I have increased the max user processor and open files value in server.



Then restarted MySQL.


Now its fixed..