Gil's Blog

I have my aviation site Planenews on a FreeBSD server. As traffic increased, I was getting more database errors. Looking around the web for clues, I discovered that FreeBSD did not have a default my.cnf file in /usr/local/etc. You can find sample files in /usr/local/share/mysql. I used my-huge.cnf, renamed it to my.cnf, put it in /usr/local/etc, et voila (don’t forget to restart MySQL)!

Problem solved? Nope.. I was still getting errors at peak traffic. I then found mysqltuner, a Perl diagnosis tool for MySQL. I was missing a few variables in my.cnf. See the file below, and notice the additions under “Added by Gil.”

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# 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
max_allowed_packet = 1M
table_cache = 512
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 = 128M
# Try number of CPU's*2 for thread_concurrency
thread_concurrency = 4

# Added b Gil:
# max_connections 250 crashes my server, use with caution..
#max_connections = 250
wait_timeout = 180
interactive_timeout = 45
tmp_table_size = 64M
max_heap_table_size = 32M

# Disable Federated by default
skip-federated
skip-innodb
skip-bdb

# 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

# Point the following paths to different dedicated disks
#tmpdir         = /tmp/
#log-update     = /path-to-dedicated-directory/hostname

[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

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The site seems to be running fine now, with no errors. I guess I will have to wait for a story to make it to a major social networking site to see if it really can take a heavy load. Please tell me about your optimization tips, and how you prepared for traffic spikes…