Re: how to update max_connections of mysql on linux

[Erin ONeill]

You should be forewarned that upping this variable will change the amount of RAM you will need. You need to redo your RAM calc. The formula is:
global buffers + (thread buffers * max_connections) = a bit less than your RAM (so the OS and some MySQL admin stuff can work.

global buffers are: key_buffer, innodb_buffer_pool, innodb_log_buffer, innodb_additional_mem_pool, net_buffer

Thread buffers are: sort_buffer, myisam_sort_buffer,read_buffer, join_buffer, read_rnd_buffer

You need to keep an eye on your max connections under status so that you can see if you REALLY need 500. Perhaps you just need to cache your threads and lower your wait timeout?

Many people think that the sort buffers are global and set them very high. Then they get a huge number of connections and the server comes down!

good luck!