# Tweak Innodb parameters **URL:** \ **Category:** Other MySQL® Questions\ **Created:** [April 10, 2008, 4:28am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711 "2008-04-10T04:28:12Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![3molo](https://avatars.discourse-cdn.com/v4/letter/3/b19c9b/32.png) [@3molo](https://forums.percona.com/u/3molo)\ **Post date:** [April 10, 2008, 4:28am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/1 "2008-04-10T04:28:12Z")
Hi, The machine has 12 gb ram. It only houses one huge cache table (flushed twice per day). The table is BLOB. Currently about 10 GB is cached, so there’s room for using more ram. I could really need some tips how to tweak it. This is my.cnf: # Uncomment the following if you are using InnoDB tables innodb\_data\_home\_dir = /var/lib/mysql/ innodb\_data\_file\_path = ibdata1:200M:autoextend innodb\_log\_group\_home\_dir = /var/lib/mysql/ innodb\_log\_arch\_dir = /var/lib/mysql/ # You can set ..\_buffer\_pool\_size up to 50 - 80 % # of RAM but beware of setting memory usage too high innodb\_buffer\_pool\_size = 384M innodb\_additional\_mem\_pool\_size = 20M # Set ..\_log\_file\_size to 25 % of buffer pool size innodb\_log\_file\_size = 100M innodb\_log\_buffer\_size = 8M innodb\_flush\_log\_at\_trx\_commit = 1 innodb\_lock\_wait\_timeout = 50 Here’s output of status for innodb params. Com\_show\_innodb\_status 0 Innodb\_buffer\_pool\_pages\_data 24475 Innodb\_buffer\_pool\_pages\_dirty 10365 Innodb\_buffer\_pool\_pages\_flushed 26657589 Innodb\_buffer\_pool\_pages\_free 71 Innodb\_buffer\_pool\_pages\_latched 52 Innodb\_buffer\_pool\_pages\_misc 30 Innodb\_buffer\_pool\_pages\_total 24576 Innodb\_buffer\_pool\_read\_ahead\_rnd 566045 Innodb\_buffer\_pool\_read\_ahead\_seq 162349 Innodb\_buffer\_pool\_read\_requests 3165607053 Innodb\_buffer\_pool\_reads 12897128 Innodb\_buffer\_pool\_wait\_free 0 Innodb\_buffer\_pool\_write\_requests 1052043302 Innodb\_data\_fsyncs 86361799 Innodb\_data\_pending\_fsyncs 0 Innodb\_data\_pending\_reads 1 Innodb\_data\_pending\_writes 0 Innodb\_data\_read 4257353728 Innodb\_data\_reads 15859383 Innodb\_data\_writes 92817184 Innodb\_data\_written 1746445824 Innodb\_dblwr\_pages\_written 26657589 Innodb\_dblwr\_writes 367841 Innodb\_log\_waits 0 Innodb\_log\_write\_requests 644676246 Innodb\_log\_writes 85553632 Innodb\_os\_log\_fsyncs 85632317 Innodb\_os\_log\_pending\_fsyncs 0 Innodb\_os\_log\_pending\_writes 0 Innodb\_os\_log\_written 70796288 Innodb\_page\_size 16384 Innodb\_pages\_created 18758388 Innodb\_pages\_read 50853538 Innodb\_pages\_written 26657589 Innodb\_row\_lock\_current\_waits 0 Innodb\_row\_lock\_time 261 Innodb\_row\_lock\_time\_avg 0 Innodb\_row\_lock\_time\_max 25 Innodb\_row\_lock\_waits 1301 Innodb\_rows\_deleted 1906012 Innodb\_rows\_inserted 84545781 Innodb\_rows\_read 213763389 Innodb\_rows\_updated 0 Any tips? ---
**Author:** ![sterin](https://avatars.discourse-cdn.com/v4/letter/s/3ab097/32.png) [@sterin](https://forums.percona.com/u/sterin)\ **Post date:** [April 12, 2008, 3:21pm UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/2 "2008-04-12T15:21:09Z")
1. Do you have any specific problems with performance? Because the only thing I can say generic is that these two: innodb\_buffer\_pool\_size = 384M innodb\_additional\_mem\_pool\_size = 20M could be increased a lot, up to about 80% of RAM which could mean something like this: innodb\_buffer\_pool\_size = 9G innodb\_additional\_mem\_pool\_size = 200M But that depends on how big you database actually is, because if your DB is smaller than that this setting is worthless and you should maybe focus on allowing more memory to be used for sorting or join buffers etc. That is why it is important to say if you experience any specific problems. 1. When you say “flushed twice per day”, what do you actually mean? That it is deleted and rebuilt or what? 1. If you are experiencing slow insert/updates but the rest is going fast then you should change this: innodb\_flush\_log\_at\_trx\_commit = 1 to a value of 2 instead. But if you do you should also be aware that if the server crashes then you could loose the last changes that you have performed in the database. ---
**Author:** ![erkules](https://avatars.discourse-cdn.com/v4/letter/e/db5fbb/32.png) [@erkules](https://forums.percona.com/u/erkules)\ **Post date:** [April 13, 2008, 3:17am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/3 "2008-04-13T03:17:27Z")
Do you know how to calculate innodb\_additional\_mem\_pool\_size? ---
**Author:** ![3molo](https://avatars.discourse-cdn.com/v4/letter/3/b19c9b/32.png) [@3molo](https://forums.percona.com/u/3molo)\ **Post date:** [April 13, 2008, 9:34am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/4 "2008-04-13T09:34:09Z")
1. no specific problem. The database can hold up to 40-50G of data. 2. It’s cached data, so the whole table (theres really only one table on it) gets dropped and rebuilt twice a day. 3. No, I dont! Thanks for your reply ---
**Author:** ![sterin](https://avatars.discourse-cdn.com/v4/letter/s/3ab097/32.png) [@sterin](https://forums.percona.com/u/sterin)\ **Post date:** [April 13, 2008, 4:12pm UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/5 "2008-04-13T16:12:54Z")
If it’s only one table then you can keep the setting: innodb\_additional\_mem\_pool\_size = 20M There is no use to allow more since it will never be used. And actually the value of 200M is very large and I want to retract that statement from my previous post. Sorry about that! 😉 erkules: No unfortunately I don’t have a good way to calculate it. But it doesn’t really matter since the only thing that will happen if this buffer is too small is that MySQL will allocate the memory anyway but it will write error messages about it to the MySQL error log. So if you see these errors turn up then you can just increase the setting. ---
**Author:** ![3molo](https://avatars.discourse-cdn.com/v4/letter/3/b19c9b/32.png) [@3molo](https://forums.percona.com/u/3molo)\ **Post date:** [April 14, 2008, 1:02am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/6 "2008-04-14T01:02:33Z")
Hi! Did not work out very well. The only thing I can think of would be the key\_buffer already so high so innodb buffer pool could not allocate its 3G I chose. (And having a key buffer above say 16M makes no sense in this case as I only have one table, an innodb so I will of course lower it) What do you think? 080414 8:22:47 InnoDB: Error: cannot allocate 3221241856 bytes of InnoDB: memory with malloc! Total allocated memory InnoDB: by InnoDB 39688400 bytes. Operating system errno: 12 InnoDB: Check if you should increase the swap file or InnoDB: ulimits of your operating system. InnoDB: On FreeBSD check you have compiled the OS with InnoDB: a big enough maximum process size. InnoDB: Note that in most 32-bit computers the process InnoDB: memory space is limited to 2 GB or 4 GB. InnoDB: We keep retrying the allocation for 60 seconds… InnoDB: Fatal error: cannot allocate the memory for the buffer pool ^G/usr/sbin/mysqld: Out of memory (Needed 3814433792 bytes) ^G/usr/sbin/mysqld: Out of memory (Needed 2860824576 bytes) 080414 8:23:47 [Note] /usr/sbin/mysqld: ready for connections. Version: ‘5.0.37-standard-log’ socket: ‘/var/lib/mysql/mysql.sock’ port: 3306 MySQL Community Edition - Standard (GPL) 080414 8:24:02 [ERROR] /usr/sbin/mysqld: Incorrect information in file: ‘./something/somethingelse.frm’ Linux [something.net](http://something.net) 2.6.9-55.0.12.ELsmp #1 SMP Fri Nov 2 11:19:08 EDT 2007 i686 i686 i386 GNU/Linux # cat /proc/meminfo MemTotal: 12469000 kB # Example MySQL config file for very large systems. # # This is for a large system with memory of 1G-2G where the system runs mainly # MySQL. # # You can copy this file to # /etc/my.cnf to set global options, # mysql-data-dir/my.cnf to set server-specific options (in this # installation this directory is /usr/local/var) or # ~/.my.cnf to set user-specific options. # # In this file, you can use all long options that a program supports. # If you want to know which options a program supports, run the program # with the “–help” option. # The following options will be passed to all MySQL clients [client] #password = your\_password port = 3306 socket = /var/lib/mysql/mysql.sock default-character-set=utf8 # Here follows entries for some specific programs # The MySQL server [mysqld] port = 3306 socket = /var/lib/mysql/mysql.sock skip-locking key\_buffer = 4096M #Edited by PM default is 1M max\_allowed\_packet = 40M table\_cache = 1024 sort\_buffer\_size = 2M read\_buffer\_size = 2M read\_rnd\_buffer\_size = 8M myisam\_sort\_buffer\_size = 64M thread\_cache\_size = 8 query\_cache\_size = 32M # Try number of CPU’s\*2 for thread\_concurrency thread\_concurrency = 8 log\_slow\_queries=/var/log/mysql/slow-queries.log long\_query\_time=2 # log-long-format wait\_timeout=600 max\_connections=2000 max\_connect\_errors=1000 default-character-set=utf8 # Don’t listen on a TCP/IP port at all. This can be a security enhancement, # if all processes that need to connect to mysqld run on the same host. # All interaction with mysqld must be made via Unix sockets or named pipes. # Note that using this option without enabling named pipes on Windows # (via the “enable-named-pipe” option) will render mysqld useless! # #skip-networking # Replication Master Server (default) # binary logging is required for replication #log-bin=mysql-bin # required unique id between 1 and 2^32 - 1 # defaults to 1 if master-host is not set # but will not function as a master if omitted server-id = 1 # Replication Slave (comment out master section to use this) # # To configure this host as a replication slave, you can choose between # two methods : # # 1) Use the CHANGE MASTER TO command (fully described in our manual) - # the syntax is: # # CHANGE MASTER TO MASTER\_HOST=, MASTER\_PORT=, # MASTER\_USER=, MASTER\_PASSWORD= ; # # where you replace , , by quoted strings and # by the master’s port number (3306 by default). # # Example: # # CHANGE MASTER TO MASTER\_HOST=‘125.564.12.1’, MASTER\_PORT=3306, # MASTER\_USER=‘joe’, MASTER\_PASSWORD=‘secret’; # # OR # # 2) Set the variables below. However, in case you choose this method, then # start replication for the first time (even unsuccessfully, for example # if you mistyped the password in master-password and the slave fails to # connect), the slave will create a master.info file, and any later # change in this file to the variables’ values below will be ignored and # overridden by the content of the master.info file, unless you shutdown # the slave server, delete master.info and restart the slaver server. # For that reason, you may want to leave the lines below untouched # (commented) and instead use CHANGE MASTER TO (see above) # # required unique id between 2 and 2^32 - 1 # (and different from the master) # defaults to 2 if master-host is set # but will not function as a slave if omitted #server-id = 2 # # The replication master for this slave - required #master-host = # # The username the slave will use for authentication when connecting # to the master - required #master-user = # # The password the slave will authenticate with when connecting to # the master - required #master-password = # # The port the master is listening on. # optional - defaults to 3306 #master-port = # # binary logging - not required for slaves, but recommended #log-bin=mysql-bin # Point the following paths to different dedicated disks #tmpdir = /tmp/ #log-update = /path-to-dedicated-directory/hostname # Uncomment the following if you are using BDB tables #bdb\_cache\_size = 384M #bdb\_max\_lock = 100000 # Uncomment the following if you are using InnoDB tables innodb\_data\_home\_dir = /var/lib/mysql/ innodb\_data\_file\_path = ibdata1:200M:autoextend innodb\_log\_group\_home\_dir = /var/lib/mysql/ innodb\_log\_arch\_dir = /var/lib/mysql/ # You can set ..\_buffer\_pool\_size up to 50 - 80 % # of RAM but beware of setting memory usage too high innodb\_buffer\_pool\_size = 3G innodb\_additional\_mem\_pool\_size = 20M # Set ..\_log\_file\_size to 25 % of buffer pool size innodb\_log\_file\_size = 256M innodb\_log\_buffer\_size = 8M innodb\_flush\_log\_at\_trx\_commit = 1 innodb\_lock\_wait\_timeout = 50 [mysqldump] quick max\_allowed\_packet = 16M [mysql] no-auto-rehash # Remove the next comment character if you are not familiar with SQL #safe-updates [isamchk] key\_buffer = 256M sort\_buffer\_size = 256M read\_buffer = 2M write\_buffer = 2M [myisamchk] key\_buffer = 256M sort\_buffer\_size = 256M read\_buffer = 2M write\_buffer = 2M [mysqlhotcopy] interactive-timeout ---
**Author:** ![safari](https://avatars.discourse-cdn.com/v4/letter/s/838e76/32.png) [@safari](https://forums.percona.com/u/safari)\ **Post date:** [April 14, 2008, 3:41am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/7 "2008-04-14T03:41:51Z")
I guess you’re using 32bit OS. Using 64bit OS to overcome this limitation. ---
**Author:** ![3molo](https://avatars.discourse-cdn.com/v4/letter/3/b19c9b/32.png) [@3molo](https://forums.percona.com/u/3molo)\ **Post date:** [April 14, 2008, 4:11am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/8 "2008-04-14T04:11:31Z")
What exactly is the limitation? ---
**Author:** ![sterin](https://avatars.discourse-cdn.com/v4/letter/s/3ab097/32.png) [@sterin](https://forums.percona.com/u/sterin)\ **Post date:** [April 14, 2008, 4:33am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/9 "2008-04-14T04:33:36Z")
You should of course lower it but I don’t think that is the problem because this buffer will not be allocated unless there are any indexes to use ti. No, your problem is probably OS related instead. Which OS are you running? Not a 64bit version i assume? Either that or you have a ulimit set globally for how much memory each process are allowed to use. On 32bit OS’es one process in itself can very rarely be allowed to allocate more than about 2-3GB due to limitations with using 32bit memory address space. And on some Linux/BSD distributions they have a global ulimit that doesn’t allow user processes to be larger than a certain size. First check the ulimit limit with: ulimit -a If it says unlimited then it is not a ulimit problem and then unfortunately you need to run a 64bit version of your OS to be able to use more memory (which I think you should anyway since you have a pretty hefty server with a lot of RAM available). And when you upgrade your OS to a 64 bit version you should also make sure that you are running a 64 bit version of MySQL ---
**Author:** ![3molo](https://avatars.discourse-cdn.com/v4/letter/3/b19c9b/32.png) [@3molo](https://forums.percona.com/u/3molo)\ **Post date:** [April 14, 2008, 4:37am UTC](https://forums.percona.com/t/tweak-innodb-parameters/711/10 "2008-04-14T04:37:25Z")
unlimited. I guess I will have to reinstall servers etc. I will revoke this thread once all is done, probably a few weeks. Thanks for your answers guys!