We've got an ec2 m2.4xlarge running Magento (centos 5.6, httpd 2.2, php 5.2.17 with eaccelerator 0.9.5.3, mysql 5.1.52). Right now we're getting a large traffic spike, and our top looks like this:
top - 09:41:29 up 31 days, 1:12, 1 user, load average: 120.01, 129.03, 113.23
Tasks: 1190 total, 18 running, 1172 sleeping, 0 stopped, 0 zombie
Cpu(s): 97.3%us, 1.8%sy, 0.0%ni, 0.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.4%st
Mem: 71687720k total, 36898928k used, 34788792k free, 49692k buffers
Swap: 880737784k total, 0k used, 880737784k free, 1586524k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2433 mysql 15 0 23.6g 4.5g 7112 S 564.7 6.6 33607:34 mysqld
24046 apache 16 0 411m 65m 28m S 26.4 0.1 0:09.05 httpd
24360 apache 15 0 410m 60m 25m S 26.4 0.1 0:03.65 httpd
24993 apache 16 0 410m 57m 21m S 26.1 0.1 0:01.41 httpd
24838 apache 16 0 428m 74m 20m S 24.8 0.1 0:02.37 httpd
24359 apache 16 0 411m 62m 26m R 22.3 0.1 0:08.12 httpd
23850 apache 15 0 411m 64m 27m S 16.8 0.1 0:14.54 httpd
25229 apache 16 0 404m 46m 17m R 10.2 0.1 0:00.71 httpd
14594 apache 15 0 404m 63m 34m S 8.4 0.1 1:10.26 httpd
24955 apache 16 0 404m 50m 21m R 8.4 0.1 0:01.66 httpd
24313 apache 16 0 399m 46m 22m R 8.1 0.1 0:02.30 httpd
25119 apache 16 0 411m 59m 23m S 6.8 0.1 0:01.45 httpd
Questions:
Would giving msyqld more memory help it cache queries and react faster?
If so, how?
Other than splitting mysql and php to separate servers (which we're about to do) is there anything else we could/should be doing?
Thanks!
UPDATE:
Here's our my.cnf along with the output of mysqltuner. It looks like a cache problem. Thanks again!
# cat /etc/my.cnf
[client]
port = ****
socket = /var/lib/mysql/mysql.sock
[mysqld]
datadir=/mnt/persistent/mysql
port=****
socket=/var/lib/mysql/mysql.sock
key_buffer = 512M
max_allowed_packet = 64M
table_cache = 1024
sort_buffer_size = 8M
read_buffer_size = 4M
read_rnd_buffer_size = 2M
myisam_sort_buffer_size = 64M
thread_cache_size = 128M
tmp_table_size = 128M
join_buffer_size = 1M
query_cache_limit = 2M
query_cache_size= 64M
query_cache_type = 1
max_connections = 1000
thread_stack = 128K
thread_concurrency = 48
log-bin=mysql-bin
server-id = 1
wait_timeout = 300
innodb_data_home_dir = /mnt/persistent/mysql/
innodb_data_file_path = ibdata1:10M:autoextend
innodb_buffer_pool_size = 20G
innodb_additional_mem_pool_size = 20M
innodb_log_file_size = 64M
innodb_log_buffer_size = 8M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50
innodb_thread_concurrency = 48
ft_min_word_len=3
[myisamchk]
ft_min_word_len=3
key_buffer = 128M
sort_buffer_size = 128M
read_buffer = 2M
write_buffer = 2M
# ./mysqltuner.pl
>> MySQLTuner 1.2.0 - Major Hayden <
[email protected]>
>> Bug reports, feature requests, and downloads at http://mysqltuner.com/
>> Run with '--help' for additional options and output filtering
-------- General Statistics --------------------------------------------------
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.1.52-log
[OK] Operating on 64-bit architecture
-------- Storage Engine Statistics -------------------------------------------
[--] Status: +Archive -BDB +Federated +InnoDB -ISAM -NDBCluster
[--] Data in MyISAM tables: 2G (Tables: 26)
[--] Data in InnoDB tables: 749M (Tables: 250)
[!!] Total fragmented tables: 262
-------- Security Recommendations -------------------------------------------
-------- Performance Metrics -------------------------------------------------
[--] Up for: 31d 2h 30m 38s (680M q [253.371 qps], 2M conn, TX: 4825B, RX: 236B)
[--] Reads / Writes: 89% / 11%
[--] Total buffers: 20.6G global + 15.1M per thread (1000 max threads)
[OK] Maximum possible memory usage: 35.4G (51% of installed RAM)
[OK] Slow queries: 0% (35K/680M)
[OK] Highest usage of available connections: 53% (537/1000)
[OK] Key buffer size / total MyISAM indexes: 512.0M/457.2M
[OK] Key buffer hit rate: 100.0% (9B cached / 264K reads)
[OK] Query cache efficiency: 42.3% (260M cached / 615M selects)
[!!] Query cache prunes per day: 4384652
[OK] Sorts requiring temporary tables: 0% (1K temp sorts / 38M sorts)
[!!] Joins performed without indexes: 100404
[OK] Temporary tables created on disk: 17% (7M on disk / 45M total)
[OK] Thread cache hit rate: 99% (537 created / 2M connections)
[!!] Table cache hit rate: 0% (1K open / 946K opened)
[OK] Open file limit used: 9% (453/5K)
[OK] Table locks acquired immediately: 99% (758M immediate / 758M locks)
[OK] InnoDB data size / buffer pool: 749.3M/20.0G
-------- Recommendations -----------------------------------------------------
General recommendations:
Run OPTIMIZE TABLE to defragment tables for better performance
Enable the slow query log to troubleshoot bad queries
Adjust your join queries to always utilize indexes
Increase table_cache gradually to avoid file descriptor limits
Variables to adjust:
query_cache_size (> 64M)
join_buffer_size (> 1.0M, or always use indexes with joins)
table_cache (> 1024)
