我按照互联网上的一些提示来调试mysql。
但网站加载速度慢，时间到第一个字节的时间非常长。因此我开始调查，据我所知，它是由mysql和高内存使用
引起的每次我根据我得到的建议对my.cnf进行更改 ./ mysqltuner.pl AND ./ tuning-primer.sh 它提出了另一个建议。实际上一些值应该相互平衡。我希望有人知道如何获得mysql的高性能使用，同时，照顾服务器健康
MariaDB服务器版本：10.0.20-MariaDB-log MariaDB服务器 服务器信息： 英特尔酷睿i7-3770 2x HDD 3,0 TB SATA 4x RAM 8192 MB DDR3 Cloudlinux + Cpanel已安装 Apache / 2.4.16 + eAccelerator + mod_pagespeed
SLOW QUERIES
Error: slow_query_log_file=/var/log/mysql/log-slow-queries.log
Current long_query_time = 10.000000 sec.
You have 1944 out of 25401054 that take longer than 10.000000 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/10.0/en/point-in-time-recovery.html
WORKER THREADS
Current thread_cache_size = 8
Current threads_cached = 6
Current threads_per_sec = 0
Historic threads_per_sec = 0
**Your thread_cache_size is fine**
MAX CONNECTIONS
Current max_connections = 151
Current threads_connected = 6
Historic max_used_connections = 43
The number of used connections is 28% of the configured maximum.
**Your max_connections variable seems to be fine.**
No InnoDB Support Enabled!
MEMORY USAGE
Max Memory Ever Allocated : 20.96 G
Configured Max Per-thread Buffers : 24.81 G
Configured Max Global Buffers : 13.89 G
Configured Max Memory Limit : 38.70 G
Physical Memory : 31.12 G
**Max memory limit exceeds 90% of physical memory**
KEY BUFFER
Current MyISAM index space = 29 M
Current key_buffer_size = 384 M
Key cache miss rate is 1 : 870
Key buffer free ratio = 78 %
**Your key_buffer_size seems to be fine**
QUERY CACHE
Query cache is enabled
Current query_cache_size = 512 M
Current query_cache_used = 222 M
Current query_cache_limit = 1.00 G
Current Query cache Memory fill ratio = 43.41 %
Current query_cache_min_res_unit = 4 K
**MySQL won't cache query results that are larger than query_cache_limit in size**
SORT OPERATIONS
Current sort_buffer_size = 16 M
Current read_rnd_buffer_size = 8 M
**Sort buffer seems to be fine**
JOINS
./tuning-primer.sh: line 402: export: `2097152': not a valid identifier
Current join_buffer_size = 128.00 M
You have had 10199 queries where a join could not use an index properly
join_buffer_size >= 4 M
**This is not advised
You should enable "log-queries-not-using-indexes"
Then look for non indexed joins in the slow query log.**
OPEN FILES LIMIT
Current open_files_limit = 16162 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 = 8000 tables
Current table_definition_cache = 8000 tables
You have a total of 7347 tables
You have 8000 open tables.
**Current table_cache hit rate is 21%
, 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 = 16 M
Of 592173 temp tables, 36% 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 = 16 M
Current table scan ratio = 74 : 1
**read_buffer_size is over 8 MB there is probably no need for such a large read_buffer**
TABLE LOCKING
Current Lock Wait ratio = 1 : 4366
**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=ALWAYS'.**
root@my [~]# ./mysqltuner.pl
>> MySQLTuner 1.4.0 - Major Hayden <major@mhtx.net>
>> Bug reports, feature requests, and downloads at http://mysqltuner.com/
>> Run with '--help' for additional options and output filtering
[!!] Currently running unsupported MySQL version 10.0.20-MariaDB-log
[OK] Operating on 64-bit architecture
-------- Storage Engine Statistics -------------------------------------------
[--] Status: +ARCHIVE +Aria +BLACKHOLE +CSV +FEDERATED +InnoDB +MRG_MyISAM
[--] Data in MyISAM tables: 82M (Tables: 925)
[--] Data in InnoDB tables: 7G (Tables: 6334)
[--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 52)
[--] Data in MEMORY tables: 0B (Tables: 2)
[!!] Total fragmented tables: 159
-------- Security Recommendations -------------------------------------------
[OK] All database users have passwords assigned
-------- Performance Metrics -------------------------------------------------
[--] Up for: 14h 42m 18s (25M q [480.374 qps], 81K conn, TX: 71B, RX: 6B)
[--] Reads / Writes: 98% / 2%
[--] Total buffers: 13.9G global + 168.3M per thread (151 max threads)
**[!!] Maximum possible memory usage: 38.7G (124% of installed RAM)**
[OK] Slow queries: 0% (1K/25M)
[OK] Highest usage of available connections: 28% (43/151)
[OK] Key buffer size / total MyISAM indexes: 384.0M/29.8M
[OK] Key buffer hit rate: 99.9% (12M cached / 14K reads)
[OK] Query cache efficiency: 44.9% (20M cached / 44M selects)
**[!!] Query cache prunes per day: 2013573**
[OK] Sorts requiring temporary tables: 0% (1K temp sorts / 1M sorts)
**[!!] Joins performed without indexes: 10207
[!!] Temporary tables created on disk: 58% (345K on disk / 592K total)**
[OK] Thread cache hit rate: 98% (1K created / 81K connections)
[OK] Table cache hit rate: 21% (8K open / 38K opened)
[OK] Open file limit used: 12% (1K/16K)
[OK] Table locks acquired immediately: 99% (10M immediate / 10M locks)
[OK] InnoDB buffer pool / data size: 10.0G/7.7G
[OK] InnoDB log waits: 0
-------- Recommendations -----------------------------------------------------
General recommendations:
**Run OPTIMIZE TABLE to defragment tables for better performance
Reduce your overall MySQL memory footprint for system stability
Increasing the query_cache size over 128M may reduce performance
Adjust your join queries to always utilize indexes
When making adjustments, make tmp_table_size/max_heap_table_size equal
Reduce your SELECT DISTINCT queries without LIMIT clauses**
Variables to adjust:
*** MySQL's maximum memory usage is dangerously high ***
*** Add RAM before increasing MySQL buffer variables ***
query_cache_size (> 512M) [see warning above]
join_buffer_size (> 128.0M, or always use indexes with joins)
tmp_table_size (> 16M)
max_heap_table_size (> 16M)
这是我设置的my.cnf设置
[mysqld]
#http://blog.secaserver.com/2011/08/mysql-recommended-my-cnf-settings-innodb-engine/
# GENERAL #
default-storage-engine=InnoDB
tmpdir=/tmp_mysql
group_concat_max_len=10000000
local-infile=1
# LOGGING #
slow_query_log = 1
slow_query_log_file=/var/log/mysql/log-slow-queries.log
long_query_time = 10
log-error = /var/log/error.log
log-queries-not-using-indexes
# CACHES AND LIMITS AND SAFETY #
max_allowed_packet = 512M #16
query_cache_size = 512M
query_cache_limit = 1024M
thread_cache_size = 8
table_definition_cache = 8000
table_open_cache = 8000
sort_buffer_size = 16M
read_buffer_size = 16M #2
read_rnd_buffer_size = 8M
join_buffer_size = 128M
thread_concurrency = 0 # Try number of CPU's*2 for thread_concurrency
key_buffer = 256M
# INNODB #
innodb_file_per_table=1
innodb_file_format = Barracuda
innodb_sort_buffer_size = 128M
innodb_data_home_dir = /var/lib/mysql
innodb_log_group_home_dir = /var/lib/mysql
innodb_thread_concurrency=0
innodb_flush_method=O_DIRECT
innodb_lock_wait_timeout = 120
innodb_buffer_pool_size=10G
innodb_log_file_size = 1536M # Set .. innodb_log_file_size to 25 % of innodb_buffer_pool_size -You can set .. innodb_buffer_pool_size up to 50 - 80 %
innodb_log_buffer_size = 3072M
innodb_additional_mem_pool_size = 20M
#innodb_read_io_threads=16
#innodb_write_io_threads=16
#innodb_io_capacity=500
#innodb_flush_log_at_trx_commit=1
#sync_binlog=1
#innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend
# MyISAM #
key_buffer_size = 384M
myisam_sort_buffer_size = 64M
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates
[myisamchk]
key_buffer_size = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
答案 0 :(得分：1)
<强>摘要
<强>详情
你的long_query_time似乎很好
不，将long_query_time调至2并密切关注慢查询。
未启用InnoDB支持！
[ - ] InnoDB表中的数据：7G（表：6334）
这些陈述相互矛盾！ InnoDB是首选引擎。其他输出似乎表明InnoDB正在使用中。 （脚本中的错误？）
最大内存限制超过物理内存的90％
[!!]最大可能内存使用量：38.7G（已安装RAM的124％）
没有缺陷的论坛。你可能确定。
你的key_buffer_size似乎很好
key_buffer应该是MyISAM_only服务器中最大的内存使用量。但是你有一个很小的数据库，所以没问题。
使用InnoDB时，innodb_buffer_pool_size应该是最大的内存用户。
您当前的价值很高：
innodb_buffer_pool_size = 10G
key_buffer_size = 384M
当前query_cache_size = 512 M
[OK]查询缓存效率：44.9％（20M缓存/ 44M选择）
[!!]每天查询缓存李子：2013573
512M会伤害到性能;限制为50M。 另外两行说QC没那么有用，并且有很多修剪开销 结论：谨慎尝试
query_cache_size = 0
query_cache_type = OFF
./ tuning-primer.sh:402：export：`2097152'：不是有效的标识符
脚本中的错误？
您应该启用“log-queries-not-using-indexes”
不，它只会使慢日志变得混乱。 没有索引的单行表，甚至没有索引的100行表都可能“足够快” 相反，请查看现有的慢查询以确定应该处理的内容。
您共有7347张表 （表：6334）
这是您数据库中的设计缺陷。
在592173个临时表中，36％是在磁盘上创建的
同样，slowlog可以帮助识别最糟糕的查询。然后我们可以通过添加索引或重新构造查询来修复它们。
[!!]总碎片表：159
运行OPTIMIZE TABLE对表进行碎片整理
忽略 - 几乎所有表格实际上都是碎片。这里没有行动项目。
[480.374 qps]
去InnoDB的一个很好的理由。
[!!]连接没有索引：10207
[!!]在磁盘上创建的临时表：58％（磁盘上345K /总共592K）**
要看慢速日志条目。让我们从你已经捕获的10秒开始吧。
#innodb_flush_log_at_trx_commit=1
建议设置为2。
（这是我第一次见到tuning-primer.sh;我没有留下深刻的印象。）
这两个博客可能很有用：
答案 1 :(得分：0)
似乎更可能是一个不完整的索引问题。
验证慢速查询的WHERE子句中的所有字段是否正确索引
如果您有Nfields-in-one索引，请尝试单独传播它们（如果它们构成单独条件的主题），因为只有第一个将真正被索引或所有N一起一个WHERE子句
< / LI>避免冗余索引（枚举类似案例或高级位）
db结构可能也需要一点点接触 - 但这实际上取决于你的数据库配置文件，当然还有数据更新和查看的方式（你可以改进使用混合类型的引擎每个案例 - 但你必须知道如何正确调整你的my.cnf