Re: Growing memory usage/processes
In the last episode (Jul 03), Dave said: Hello all, I have mysql running on a 2.4.18 kernel: /usr/libexec/mysqld Ver 3.23.49 for redhat-linux-gnu on i386 and note that one started about 4 processes (threads?) began to handle the various signal/table tasks and such. After several random queries the process list grows accordingly. After a couple hours all processes which showed consumption of about 8MB of memory initially are now 25MB each and growing as queries are received. My question is...Why if these are threads does it require each thread to utilize so much memory? 4 threads using 10MB each is ok, 10 threads using 10MB each is ok. 20 threads using 25MB each is too much. No. Threads share the same address space. You are seeing one threaded application consuming 25MB. Linux's threads implentation creates a separate process for each thread and top has no idea they're really all one application. Linux is the only OS that does this, afaik, and you would not believe the number of times your question has been asked on this list. On Solaris and Tru64, at least, a threaded app shows up as one entry in top. -- Dan Nelson [EMAIL PROTECTED] - 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
Re: Growing memory usage/processes
Thanks for the confirmation Dan, I will look a little closer but I could have sworn when I shutdown MySQL about 300MB of memory got freed. I had a suspicion the case was one process and ps/top could not distinguish...I just needed to hear confirmation of it I guess. -Dave In the last episode (Jul 03), Dave said: Hello all, I have mysql running on a 2.4.18 kernel: /usr/libexec/mysqld Ver 3.23.49 for redhat-linux-gnu on i386 and note that one started about 4 processes (threads?) began to handle the various signal/table tasks and such. After several random queries the process list grows accordingly. After a couple hours all processes which showed consumption of about 8MB of memory initially are now 25MB each and growing as queries are received. My question is...Why if these are threads does it require each thread to utilize so much memory? 4 threads using 10MB each is ok, 10 threads using 10MB each is ok. 20 threads using 25MB each is too much. No. Threads share the same address space. You are seeing one threaded application consuming 25MB. Linux's threads implentation creates a separate process for each thread and top has no idea they're really all one application. Linux is the only OS that does this, afaik, and you would not believe the number of times your question has been asked on this list. On Solaris and Tru64, at least, a threaded app shows up as one entry in top. -- Dan Nelson [EMAIL PROTECTED] - 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 - 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
Re: Growing memory usage/processes
Hi, Hi, It depends also of how many threads are running at the same time + sort buffer / record buffer values. The memory consumption can be roughly calculated as key buffer + (sort buffer + record buffer) * number of thread. As you can see, only the key buffer is shared between all the threads. If you want to lower the number of sleeping thread, take a look at the wait_timeout variable in your my.cnf file. Regards, Jocelyn - Original Message - From: Dave [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, July 04, 2002 8:39 AM Subject: Re: Growing memory usage/processes Thanks for the confirmation Dan, I will look a little closer but I could have sworn when I shutdown MySQL about 300MB of memory got freed. I had a suspicion the case was one process and ps/top could not distinguish...I just needed to hear confirmation of it I guess. -Dave In the last episode (Jul 03), Dave said: Hello all, I have mysql running on a 2.4.18 kernel: /usr/libexec/mysqld Ver 3.23.49 for redhat-linux-gnu on i386 and note that one started about 4 processes (threads?) began to handle the various signal/table tasks and such. After several random queries the process list grows accordingly. After a couple hours all processes which showed consumption of about 8MB of memory initially are now 25MB each and growing as queries are received. My question is...Why if these are threads does it require each thread to utilize so much memory? 4 threads using 10MB each is ok, 10 threads using 10MB each is ok. 20 threads using 25MB each is too much. No. Threads share the same address space. You are seeing one threaded application consuming 25MB. Linux's threads implentation creates a separate process for each thread and top has no idea they're really all one application. Linux is the only OS that does this, afaik, and you would not believe the number of times your question has been asked on this list. On Solaris and Tru64, at least, a threaded app shows up as one entry in top. -- Dan Nelson [EMAIL PROTECTED] - 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 - 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 - 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
