PHP|Débutant :: Forums

Merci JC

Le phénomène est très curieux. La montée en charge se produit depuis 2 jours plutôt entre 23:00 et 3:00 du matin. En journée, j'ai beaucoup plus de traffic, et pas de soucis de consommation mémoire / CPU.

Mon architecture est la suivante: 5.1.63-0+squeeze1-log (Debian)-Apache/2.2.16 (Debian)
-PHP 5.3.3-7+squeeze13 with Suhosin-Patch

Nous utilisons le framework Zend pour la partie applicative.
Nous avons un mix forum PHPBB en MYISAM et le reste en INNODB

Resultat d'un tuning_primer

        -- MYSQL PERFORMANCE TUNING PRIMER --
             - By: Matthew Montgomery -

MySQL Version 5.1.63-0+squeeze1-log x86_64

Uptime = 0 days 7 hrs 21 min 30 sec
Avg. qps = 62
Total Questions = 1666206
Threads Connected = 1

Warning: Server has not been running for at least 48hrs.
It may not be safe to use these recommendations

To find out more information on how each of these
runtime variables effects performance visit:
http://dev.mysql.com/doc/refman/5.1/en/ … ables.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 enabled.
Current long_query_time = 5.000000 sec.
You have 27 out of 1666228 that take longer than 5.000000 sec. to complete
Your long_query_time seems to be fine

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/5.1/en/ … overy.html

WORKER THREADS
Current thread_cache_size = 16
Current threads_cached = 14
Current threads_per_sec = 0
Historic threads_per_sec = 0
Your thread_cache_size is fine

MAX CONNECTIONS
Current max_connections = 200
Current threads_connected = 2
Historic max_used_connections = 104
The number of used connections is 52% of the configured maximum.
Your max_connections variable seems to be fine.

INNODB STATUS
Current InnoDB index space = 76 M
Current InnoDB data space = 314 M
Current InnoDB buffer pool free = 87 %
Current innodb_buffer_pool_size = 1.00 G
Depending on how much space your innodb indexes take up it may be safe
to increase this value to up to 2 / 3 of total system memory

MEMORY USAGE
Max Memory Ever Allocated : 3.14 G
Configured Max Per-thread Buffers : 912 M
Configured Max Global Buffers : 2.68 G
Configured Max Memory Limit : 3.57 G
Physical Memory : 15.69 G
Max memory limit seem to be within acceptable norms

KEY BUFFER
Current MyISAM index space = 17 M
Current key_buffer_size = 700 M
Key cache miss rate is 1 : 7474
Key buffer free ratio = 80 %
Your key_buffer_size seems to be fine

QUERY CACHE
Query cache is enabled
Current query_cache_size = 1.00 G
Current query_cache_used = 187 M
Current query_cache_limit = 16 M
Current Query cache Memory fill ratio = 18.33 %
Current query_cache_min_res_unit = 4 K
Your query_cache_size seems to be too high.
Perhaps you can use these resources elsewhere
MySQL won't cache query results that are larger than query_cache_limit in 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 = 2.00 M
You have had 7538 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 = 4306 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_open_cache = 2048 tables
Current table_definition_cache = 256 tables
You have a total of 217 tables
You have 351 open tables.
The table_cache value seems to be fine

TEMP TABLES
Current max_heap_table_size = 1.00 G
Current tmp_table_size = 1.00 G
Of 39951 temp tables, 46% were created on disk
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 = 473 : 1
read_buffer_size seems to be fine

TABLE LOCKING
Current Lock Wait ratio = 1 : 4148
You may benefit from selective use of InnoDB.
If you have long running SELECT's against MyISAM tables and perform
frequent updates consider setting 'low_priority_updates=1'
If you have a high concurrency of inserts on Dynamic row-length tables
consider setting 'concurrent_insert=2'.

Resultat d'un mysql tunner

>> MySQLTuner 1.2.0 - Major Hayden <major@mhtx.net>
>> Bug reports, feature requests, and downloads at http://mysqltuner.com/
>> Run with '--help' for additional options and output filtering
[OK] Logged in using credentials from debian maintenance account.

-------- General Statistics --------------------------------------------------
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.1.63-0+squeeze1-log
[OK] Operating on 64-bit architecture

-------- Storage Engine Statistics -------------------------------------------
[--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster
[--] Data in MyISAM tables: 247M (Tables: 122)
[--] Data in InnoDB tables: 314M (Tables: 71)
[--] Data in MEMORY tables: 0B (Tables: 1)
[!!] Total fragmented tables: 77

-------- Security Recommendations -------------------------------------------
[OK] All database users have passwords assigned

-------- Performance Metrics -------------------------------------------------
[--] Up for: 7h 22m 28s (1M q [62.888 qps], 142K conn, TX: 62B, RX: 895M)
[--] Reads / Writes: 92% / 8%
[--] Total buffers: 3.7G global + 4.6M per thread (200 max threads)
[OK] Maximum possible memory usage: 4.6G (29% of installed RAM)
[OK] Slow queries: 0% (27/1M)
[OK] Highest usage of available connections: 52% (104/200)
[OK] Key buffer size / total MyISAM indexes: 700.0M/17.5M
[OK] Key buffer hit rate: 100.0% (12M cached / 1K reads)
[OK] Query cache efficiency: 71.7% (924K cached / 1M selects)
[!!] Query cache prunes per day: 475216
[OK] Sorts requiring temporary tables: 3% (5K temp sorts / 151K sorts)
[!!] Joins performed without indexes: 7551
[!!] Temporary tables created on disk: 46% (34K on disk / 74K total)
[OK] Thread cache hit rate: 99% (298 created / 142K connections)
[OK] Table cache hit rate: 24% (351 open / 1K opened)
[OK] Open file limit used: 7% (323/4K)
[OK] Table locks acquired immediately: 99% (793K immediate / 794K locks)
[OK] InnoDB data size / buffer pool: 314.5M/1.0G

-------- Recommendations -----------------------------------------------------
General recommendations:
Run OPTIMIZE TABLE to defragment tables for better performance
MySQL started within last 24 hours - recommendations may be inaccurate
Increasing the query_cache size over 128M may reduce performance
Adjust your join queries to always utilize indexes
Temporary table size is already large - reduce result set size
Reduce your SELECT DISTINCT queries without LIMIT clauses
Variables to adjust:
query_cache_size (> 1G) [see warning above]
join_buffer_size (> 2.0M, or always use indexes with joins)

Pour les tables: 135 table(s)     Somme     ~819 518     MyISAM     utf8_general_ci     420,7 Mio     273,2 Kio
C'est PHP qui pilote

Les probs ont été constatés avec 130 accès concurrentiels. Mes CPU étaient chargés à 100% pendant plusieurs heures avec une mémoire et un nombre de process apache qui augmentait.

Ma conf Apache:

Timeout 30

#
# KeepAlive: Whether or not to allow persistent connections (more than
# one request per connection). Set to "Off" to deactivate.
#
KeepAlive Off
ServerLimit 400
#
# MaxKeepAliveRequests: The maximum number of requests to allow
# during a persistent connection. Set to 0 to allow an unlimited amount.
# We recommend you leave this number high, for maximum performance.
#
MaxKeepAliveRequests 2048

#
# KeepAliveTimeout: Number of seconds to wait for the next request from the
# same client on the same connection.
#
KeepAliveTimeout 3
<IfModule mpm_prefork_module>
    StartServers         10
    MinSpareServers      32
    MaxSpareServers     64
    MaxClients         400
    ServerLimit        400
  MaxRequestsPerChild  10000
</IfModule>

J'ai lancé un server-status Apache et j'ai juste constaté que certaines pages prennaient 20 à 25% de charges CPU alors qu'habituellement nous tournons à 2%
J'ai lancé une defrag des tables et une optimization .. c'est ma dernière action ..