Geoffrey, ----- Original Message ----- From: "Geoffrey" <[EMAIL PROTECTED]> To: "Heikki Tuuri" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Saturday, February 07, 2004 10:11 PM Subject: Re: Memory Leak using InnoDB ?
> Dan, Heikki, > > ----- Original Message ----- > From: "Heikki Tuuri" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Saturday, February 07, 2004 11:39 AM > Subject: Re: Memory Leak using InnoDB ? > > > > Geoffrey, Dan, > > > > ----- Original Message ----- > > From: "Dan Nelson" <[EMAIL PROTECTED]> > > Newsgroups: mailing.database.myodbc > > Sent: Saturday, February 07, 2004 5:27 AM > > Subject: Re: Memory Leak using InnoDB ? > > > > > > > In the last episode (Feb 07), Geoffrey said: > > > > I'm running MySQL 4.0.17 with RH Linux 8 on Xeon 3.0/1GB RAM. > > > > > > > > One application has to access the database (1 connection to the DB is > > > > open on startup and left open). However this application performs a > > > > lot of queries on the DB. > > > > > > > > Thanks to "top", I can see that the "used memory" is constantly > > > > increasing and never freed (up to 1 GB) when performing a lot of > > > > queries. In fact, I can see the total memory usage increasing but the > > > > mysqld process memory usage remains the same. > > > > > > > > When the DB is not accessed, the memory usage is stable. Stopping > MySQL > > > > server doesn't free the abnormaly allocated memory. > > > > > > Ideally, you should have very little "free" memory according to top > > > (most systems will see under 20MB free). Free memory is wasted memory. > > > Unix uses memory not allocated to processes for a disk cache. To > > > determine whether you are truly low on memory, run iostat and watch the > > > swap columns. Constant swap activity means you're low on memory. > > > > Dan is right. A memory leak in the mysqld process should show up in the > > 'top' line for that process. > > > > By the way, monitoring if InnoDB has memory leaks is very easy. Just look > > with SHOW INNODB STATUS at the 'total allocated memory'. If that keeps > > climbing without bounds, that is an indication of a memory leak. > > > > Thanks for your help. > > For testing, I tried the following my.cnf : > > server-id=1 > socket=/tmp/mysql.sock > innodb_data_file_path = ibdata1:750M:autoextend > set-variable = innodb_buffer_pool_size=50M > set-variable = innodb_additional_mem_pool_size=10M > set-variable = innodb_log_file_size=300M > set-variable = innodb_log_buffer_size=2M > innodb_flush_log_at_trx_commit=0 > skip-locking > set-variable = max_connections=5 > set-variable = read_buffer_size=1M > set-variable = sort_buffer=1M > set-variable = key_buffer=10M > > Here is the result of "top" after 20 hours : > > 8:26pm up 18:35, 1 user, load average: 0.42, 0.26, 0.20 > 46 processes: 44 sleeping, 2 running, 0 zombie, 0 stopped > CPU states: 3.7% user, 0.5% system, 0.0% nice, 95.6% idle > Mem: 1031048K av, 1021460K used, 9588K free, 0K shrd, 55288K > buff > Swap: 2044072K av, 0K used, 2044072K free 845544K > cached > PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND > 960 mysql 15 0 67872 66M 2656 S 0.1 6.5 6:29 mysqld > > Here is the result of "top" after a reboot : > > 8:54pm up 9 min, 1 user, load average: 0.16, 0.17, 0.10 > 46 processes: 44 sleeping, 2 running, 0 zombie, 0 stopped > CPU states: 4.5% user, 0.3% system, 0.0% nice, 95.0% idle > Mem: 1031048K av, 136512K used, 894536K free, 0K shrd, 13276K > buff > Swap: 2044072K av, 0K used, 2044072K free 61620K > cached > PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND > 774 mysql 15 0 36276 35M 2496 S 0.7 3.5 0:03 mysqld > > Here is the SHOW INNODB STATUS after 20 hours : > > ---------------------- > BUFFER POOL AND MEMORY > ---------------------- > Total memory allocated 75115912; in additional pool allocated 1611008 > Buffer pool size 3200 > Free buffers 1 > Database pages 3091 > Modified db pages 160 > Pending reads 0 > Pending writes: LRU 0, flush list 0, single page 0 > Pages read 7212, created 2274, written 801221 > 0.00 reads/s, 0.02 creates/s, 12.45 writes/s > Buffer pool hit rate 1000 / 1000 > > As far as I understand, the "Total Mem" increasing constantly when MySQL is > heavily accessed is not really memory allocated by MySQL but allocated by > Linux to take advantage of the unused memory ? > > So I should not pay attention to it (as long as used swap is 0). > > Correct ? correct! > Regards. Best regards, Heikki Tuuri Innobase Oy http://www.innodb.com Foreign keys, transactions, and row level locking for MySQL InnoDB Hot Backup - a hot backup tool for InnoDB which also backs up MyISAM tables Order MySQL technical support from https://order.mysql.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
