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MySQL Slow With 4GB Memory - Tuning Required?

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TomBarrand

Programmer
Aug 9, 2000
162
GB
Hi,

I am using MySQL 4.1 on Linux (IBM Open Power Server). The Server has 4GB memory, 380GB hard drive.

I have a Java based application that runs in Tomcat in a Windows environment using SQL Server. As part of a customer project I have got the application to work on Tomcat on Linux with MySQL.

Both databases have a large amount of data in some of the tables, e.g. 500,000+ records in some of the tables. Some of the tables have indexes on them.

There is a specifc part of the application that is slow when running against MySQL (10 seconds to write a record to a table with 500,000+ records in it.) The same bit of functionality running against SQL Server is instance, e.g. 2 secomds max. The code is doing an insert statement. Once the insert has taken place we need to get the ID for the inserted record. This is using SELECT MAX....... The ID column is set as the Primary Key and is indexed.

I am presuming that some tweaks need to be made to MySQL so that it is optimised to handle this large amount of data.

Any ideas?

I have attached the my.cnf file below

Thanks for your help


----------------------------------------------------------------------------------

# 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/mysql/data) 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 = /tmp/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
[mysqld]
port = 3306
socket = /tmp/mysql.sock
skip-locking
#key_buffer = 384M
key_buffer = 1GB
key_buffer_size = 1GB
max_allowed_packet = 1GB
table_cache = 512
sort_buffer_size = 2M
read_buffer_size = 2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 64M
#thread_cache = 8
thread_cache = 20
query_cache_size = 32M
# Try number of CPU's*2 for thread_concurrency
thread_concurrency = 8
max_connections = 500
max_user_connections = 500
max_connect_errors = 999999
back_log = 100

# 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

# 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=<host>, MASTER_PORT=<port>,
# MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
#
# where you replace <host>, <user>, <password> by quoted strings and
# <port> 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 = <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user = <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password = <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port = <port>
#
# binary logging - not required for slaves, but recommended
#log-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 = /usr/local/mysql/data/
#innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend
#innodb_log_group_home_dir = /usr/local/mysql/data/
#innodb_log_arch_dir = /usr/local/mysql/data/
# 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

[mysqldump]
quick
max_allowed_packet = 1GB

[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
 
one thing:

set primary key as autoincrement and try to fetch last insert id by sql function

SELECT LAST_INSERT_ID();

or try to fetch it with your application


gry online
 
Thanks for that.

That was going to be my next change.

Would you say that my my.cnf config file is configured correctly for my environment?

Thanks for your help
 
Would you say that my my.cnf config file is configured correctly for my environment?

Sorry but i don't know too much about mysql config
I suggest you only to use other statement to retrieve inserted ID

Tell me one more thing - what your table looks like?
Maybe you have other indexes like full text ?


gry online
 
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