MySQL Server Hosting
Tuning MySQL Server in a hosting environment can be a can of worms. This script -
http://www.day32.com/MySQL/tuning-primer.sh
will help diagnose possible configuration issues.
This script takes information from “SHOW STATUS LIKE…” and “SHOW VARIABLES LIKE…”
to produce sane recommendations for tuning server variables.
It is compatible with all versions of MySQL 3.23 and higher (including 5.1).
Currently it handles recommendations for the following:
- Was manfest in MEMORY USAGE section where total system RAM > 4GB.
- Other values may have the same issue but are not yet reported
- Use /proc/meminfo vs free -b and avoid inclusion of swap space.
Example Output -
MySQL Version 4.1.22-standard i686
Uptime = 103 days 22 hrs 14 min 37 sec
Avg. qps = 460
Total Questions = 4131113780
Threads Connected = 5
Server has been running for over 48hrs.
It should be safe to follow these recommendations
To find out more information on how each of these
runtime variables effects performance visit:
http://dev.mysql.com/doc/refman/4.1/en/server-system-variables.html
Visit http://www.mysql.com/products/enterprise/advisors.html
for info about MySQL’s Enterprise Monitoring and Advisory Service
SLOW QUERIES
The slow query log is NOT enabled.
Current long_query_time = 10 sec.
You have 740 out of 4131113798 that take longer than 10 sec. to complete
Your long_query_time may be too high, I typically set this under 5 sec.
BINARY UPDATE LOG
The binary update log is NOT enabled.
You will not be able to do point in time recovery
See http://dev.mysql.com/doc/refman/4.1/en/point-in-time-recovery.html
WORKER THREADS
Current thread_cache_size = 0
Current threads_cached = 0
Current threads_per_sec = 1
Historic threads_per_sec = 0
Your thread_cache_size is fine
MAX CONNECTIONS
Current max_connections = 500
Current threads_connected = 3
Historic max_used_connections = 153
The number of used connections is 30% of the configured maximum.
Your max_connections variable seems to be fine.
MEMORY USAGE
Max Memory Ever Allocated : 429 M
Configured Max Per-thread Buffers : 1 G
Configured Max Global Buffers : 17 M
Configured Max Memory Limit : 1 G
Physical Memory : 3.95 G
Max memory limit seem to be within acceptable norms
KEY BUFFER
Current MyISAM index space = 510 M
Current key_buffer_size = 7 M
Key cache miss rate is 1 : 10620
Key buffer fill ratio = 51.00 %
Your key_buffer_size seems to be too high.
Perhaps you can use these resources elsewhere
QUERY CACHE
Query cache is supported but not enabled
Perhaps you should set the query_cache_size
SORT OPERATIONS
Current sort_buffer_size = 2 M
Current read_rnd_buffer_size = 256 K
Sort buffer seems to be fine
JOINS
Current join_buffer_size = 132.00 K
You have had 10658991 queries where a join could not use an index properly
You should enable “log-queries-not-using-indexes”
Then look for non indexed joins in the slow query log.
If you are unable to optimize your queries you may want to increase your
join_buffer_size to accommodate larger joins in one pass.
Note! This script will still suggest raising the join_buffer_size when
ANY joins not using indexes are found.
OPEN FILES LIMIT
Current open_files_limit = 2500 files
The open_files_limit should typically be set to at least 2x-3x
that of table_cache if you have heavy MyISAM usage.
Your open_files_limit value seems to be fine
TABLE CACHE
Current table_cache value = 64 tables
You have a total of 470 tables
You have 64 open tables.
Current table_cache hit rate is 0%, while 100% of your table cache is in use
You should probably increase your table_cache
TEMP TABLES
Current max_heap_table_size = 16 M
Current tmp_table_size = 32 M
Of 12574936 temp tables, 98% were created on disk
Effective in-memory tmp_table_size is limited to max_heap_table_size.
Perhaps you should increase your tmp_table_size and/or max_heap_table_size
to reduce the number of disk-based temporary tables
Note! BLOB and TEXT columns are not allow in memory tables.
If you are using these columns raising these values might not impact your
ratio of on disk temp tables.
TABLE SCANS
Current read_buffer_size = 128 K
Current table scan ratio = 1 : 1
read_buffer_size seems to be fine
TABLE LOCKING
Current Lock Wait ratio = 1 : 118167
Your table locking seems to be fine
If your website depends on MySQL then don’t leave performance tuning to chance, contact ForLinux now for a tuned MySQL hosted server on 01636 881200 or complete the contact form on the right.
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