Hi, So I use mysql as the DB for a large site (up to 10000 concurrent users at peaks). I have a front server as a reverse proxy and multiple (7) backend machines serving the site. Each machine has data strictly similar in nature and quantity.
On 6 of these machines, I have 1 single mysqld process (process in linux terms): # ps -ef | grep mysqld | wc -l 2 There are generally 5-8 threads (processes as mysql means it) running when i do a show processlist; Now, on one of those machines there are huge number of processes for mysql. # ps -ef | grep mysqld | wc -l 34 Running just ps shows for each of these processes: mysql 25952 10073 0 16:25 ? 00:00:02 /usr/sbin/mysqld --defaults-file=/etc/mysql/my.cnf --basedir=/usr --datadir=/var/lib/mysql --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock This machine has no particular data, is doing nothing different than the others. The show processlist command also returns 5-8 processes. So where are these myqsld processes from ? There's like 20 at startup (instantly after launching mysql), but it keeps increasing, until i restart mysql or the server runs out of memory. I have compared the mysql configuration of this machine and the 6 other, variable by variable, and they are strictly identical. How come this server behaves differently ? What can I do to have the single-process behaviour on that machine too ? Thanks, Quentin
