On Thu, 12 Dec 2002 18:41:05 -0700 Mariella Di Giacomo <[EMAIL PROTECTED]> wrote:
> Hello, > > I am running MySQL 4.0.5b 64 bits on a Solaris 2.8. > The server used has 8 CPUs. > > MySQL DB has access (and menage) in that system 2DBs. > The first DB is only is accessed only through SELECTS and the > second one has been used for UPDATES and INSERTS. > > Initially I was running a process that was updating the tables. > In the program there is no contention among tables and there is only > one process that executes UPDATES AND INSERTS. > > Apparently as soon as people start accessing the other DB (quite > heavily) the time spent by MySQL in > > lwp_mutex_wakeup > lwp_mutex_lock > > > increases a lot . > > This is a screen shot taken with truss of the process in a certain > timeframe. > > ____________________ > > As soon as all the shutdown all the users from the DB that is used for > only SELECT, > now the same process that runs MySQL updates on the other DB has hardly > ever lwp_mutex_wakeup > lwp_mutex_lock > calls. > > > Could someone, please, help me trying to understand why that is the > behavior ? > > Thanks a lot, > > Mariella > > > The above is not necessarily related to UPDATE's of DELETE's, but to the more frequent creation / destruction of threads. MySQL enforces quite a few locks in order to enable safe operation, safe statistics colletion, memory management etc. -- Regards, -- For technical support contracts, go to https://order.mysql.com/?ref=msmi __ ___ ___ ____ __ / |/ /_ __/ __/ __ \/ / Mr. Sinisa Milivojevic <[EMAIL PROTECTED]> / /|_/ / // /\ \/ /_/ / /__ MySQL AB, FullTime Developer /_/ /_/\_, /___/\___\_\___/ Larnaca, Cyprus <___/ www.mysql.com --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
