Hello,

the issue is, that on bigger traffic mysql works so slowly....
I have a quite big website, with few servers in cluster. Works quite good. But I got x3 more traffic, and seems website working very slowly, the reason is mysql.... We moved mysql to separate server, a lit helped but still not so good... Could anybody help me to optimzate mysql performance (queries, tables and etc...)

Thanks

One way you can do this is to start logging slow queries. Check out MySQL Query Log. Once you got the list of slow queries, then you can start improving it.

Another option is to use some kind of caching like Memcache.

one more way is to use efficient db setup , use indexing and caching for faster responses , indexing usually works pretty well if you have large number of un-associated data and caching really helps avoid overload and bottleneck in db server