I have a mysql server which has 60gb of ram and it uses too much system resources. Top command result;

Mem:   64555285k total, 64151125k used

I think there is something terribly wrong with my mysql conf.Here is my mysql conf;

query_cache_size = 50M
thread_cache_size =32
table_open_cache = 1000
innodb_buffer_pool_size = 35G   
innodb_log_buffer_size = 70M
join_buffer_size= 8G
tmp_table_size = 64M
max_heap_table_size = 64M
query_cache_type = 1  

Is there anything wrong with my mysql conf?


1 Answer 1


join_buffer_size= 8G is dangerously high. If you have a lot of queries running, all needing the "join buffer", you could quickly run out of RAM, as you appear to have.

8M is a better value for that setting. Keep in mind that if a query 'wants' a join buffer, it will either use the space you provide or perform the query a different way.

max_connections=8000 is quite high. What is the status value of Max_used_connections? If it is more than a few hundred, we should discuss why it is so large. That could have an impact on memory usage -- many things are "per connection".

Another possibility... What else is running? Could it be chewing up RAM?

For a more thorough review, provide SHOW VARIABLES; and SHOW GLOBAL STATUS; (perhaps on some postit site).

Not the answer you're looking for? Browse other questions tagged or ask your own question.