MySQL 中的某些内容导致负载逐渐升高，几乎消耗了所有内存
Vas*_*iki 6 mysql mysqld mysql-5.7
我的服务器只有一个站点和一个数据库。然而，我无法调整它以使负载恢复正常。
如果我重新启动 mysql 服务，内存和负载会下降到正常，但几天后，内存和负载会逐渐增加。
服务器规格
- 森托斯7
- 总内存7.8G
- 交换1G
顶部输出
MySQL版本
mysql Ver 14.14 Distrib 5.7.28, for Linux (x86_64) using EditLine wrapper
我的cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
#[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
#datadir=/var/lib/mysql
#socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
#symbolic-links=0
#log-error=/var/log/mysqld.log
#pid-file=/var/run/mysqld/mysqld.pid
#max_allowed_packet=1024M
##################
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
plugin-load-add=validate_password.so
max_allowed_packet=100M
#------------------| query cach config
# https://easyengine.io/tutorials/mysql/query-cache
#------------------|
query_cache_type = 1
query_cache_size = 256M
query_cache_limit = 2M
#query_cache_strip_comments =1
port = 3306
#socket = /var/lib/mysql/mysql.sock
#skip-external-locking
key_buffer_size = 512M
max_allowed_packet=268435456
table_open_cache = 256
sort_buffer_size = 256
read_buffer_size = 256
read_rnd_buffer_size = 40
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size= 16M
# Try number of CPU's x 2 for thread_concurrency
#thread_concurrency = 2
# Point the following paths to different dedicated disks
#tmpdir = /tmp/
# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
#
#skip-networking
# Replication Master Server (default)
# binary logging is required for replication
#log-bin=mysql-bin
# binary logging format - mixed recommended
binlog_format=mixed
# 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
# ============================================================ #
# =============== Custom server tweaks [start] =============== #
# ============================================================ #
default_storage_engine = InnoDB
innodb_buffer_pool_size = 2G #4G # 8G # Use up to 70-80% of RAM & optionally check if /proc/sys/vm/swappiness is set to 0. Use Tuning Primer or MySQL Tuner to adjust accordingly.
innodb_file_per_table = 1
#--------------------------|
# 2 means log buffer is flushed to OS file cache on every transaction commit.
# The implication of 2 is optimal and improve performance
# if you are not concerning ACID and can lose transactions for last second or two in case of OS crashes
# -------------------------|
innodb_flush_log_at_trx_commit = 2
innodb_flush_method = O_DIRECT
innodb_log_buffer_size = 16M
#---------------------------|
# Delete the ib_logfile0 & ib_logfile1 files in /var/lib/mysql whenever you change this,
# even the first time you set it up, as the default value is 8M.
# Don't go above 256M.
# ref: https://gist.github.com/wh4u/1fafe2bf98f630d7753717b5a8835bca
#---------------------------|
innodb_log_file_size = 256M
innodb_file_per_table=ON
innodb_stats_on_metadata = OFF
innodb_buffer_pool_instances = 8 #(or 1 if innodb_buffer_pool_size < 1GB)
#query_cache_type = 0
#query_cache_size = 0 #(disabling mutex)
#---------------|
# ref: http://techinfobest.com/optimize-mysql-table_open_cache/
# --------------|
#open_files_limit=10000
open_files_limit=19107
table_open_cache=39390
slow-query-log=1
long_query_time = 1
log-queries-not-using-indexes = 1
[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 = 128M
sort_buffer_size = 128M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
几天后 htop 输出
如果我不重新启动 MySQL，这就是 3-4 天后发生的情况
有人可以指出我正确的方向吗？
额外细节
稍后 MySQL 崩溃了，日志中显示以下消息：
2020-01-03T12:59:51.514413Z 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4887ms. The settings might not be optimal. (flushed=142 and evicted=0, during the time.)
2020-01-03T13:00:35.061257Z 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 11874ms. The settings might not be optimal. (flushed=89 and evicted=0, during the time.)
2020-01-03T13:01:13.857771Z 0 [Warning] Could not increase number of max_open_files to more than 5000 (request: 78941)
2020-01-03T13:01:13.858498Z 0 [Warning] Changed limits: table_open_cache: 2419 (requested 39390)
2020-01-03T13:01:14.177515Z 0 [Warning] option 'sort_buffer_size': unsigned value 256 adjusted to 32768
2020-01-03T13:01:14.177549Z 0 [Warning] option 'read_buffer_size': unsigned value 256 adjusted to 8192
2020-01-03T13:01:14.177630Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2020-01-03T13:01:14.420855Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.28-log) starting as process 15029 ...
2020-01-03T13:01:15.607997Z 0 [Warning] You need to use --log-bin to make --binlog-format work.
2020-01-03T13:01:15.758435Z 0 [Note] InnoDB: PUNCH HOLE support available
2020-01-03T13:01:15.758521Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2020-01-03T13:01:15.758535Z 0 [Note] InnoDB: Uses event mutexes
2020-01-03T13:01:15.758552Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2020-01-03T13:01:15.758563Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2020-01-03T13:01:15.758574Z 0 [Note] InnoDB: Using Linux native AIO
2020-01-03T13:01:15.759295Z 0 [Note] InnoDB: Number of pools: 1
2020-01-03T13:01:15.759589Z 0 [Note] InnoDB: Using CPU crc32 instructions
2020-01-03T13:01:15.773538Z 0 [Note] InnoDB: Initializing buffer pool, total size = 2G, instances = 8, chunk size = 128M
2020-01-03T13:01:16.072379Z 0 [Note] InnoDB: Completed initialization of buffer pool
2020-01-03T13:01:16.142472Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2020-01-03T13:01:16.237526Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2020-01-03T13:01:16.349890Z 0 [Note] InnoDB: Log scan progressed past the checkpoint lsn 82179195773
2020-01-03T13:01:16.349986Z 0 [Note] InnoDB: Doing recovery: scanned up to log sequence number 82179207508
2020-01-03T13:01:16.471207Z 0 [Note] InnoDB: Database was not shutdown normally!
我尝试了重复问题建议中提供的解决方案，但这使事情变得更糟。服务器在几分钟内就会耗尽内存。
更新
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 2198863872
Dictionary memory allocated 1654382
Buffer pool size 131072
Free buffers 1
Database pages 128972
Old database pages 47448
Modified db pages 1578
Pending reads 1
Pending writes: LRU 0, flush list 163, single page 0
Pages made young 17903348, not young 602752081
0.00 youngs/s, 0.00 non-youngs/s
Pages read 75403666, created 44758503, written 47149356
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
Buffer pool hit rate 997 / 1000, young-making rate 0 / 1000 not 67 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 128972, unzip_LRU len: 0
I/O sum[106576]:cur[1912], unzip sum[0]:cur[0]
Old database pages太多了吗？您看到什么问题？
更新 #2 这是 my.cnf 目前的样子
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
#[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
#datadir=/var/lib/mysql
#socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
#symbolic-links=0
#log-error=/var/log/mysqld.log
#pid-file=/var/run/mysqld/mysqld.pid
#max_allowed_packet=1024M
##################
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
plugin-load-add=validate_password.so
max_allowed_packet=100M
#------------------| query cach config
# https://easyengine.io/tutorials/mysql/query-cache
#------------------|
query_cache_type = 1
query_cache_size = 256M
query_cache_limit = 2M
#query_cache_strip_comments =1
port = 3306
#socket = /var/lib/mysql/mysql.sock
#skip-external-locking
key_buffer_size = 512M
max_allowed_packet=268435456
#table_open_cache = 256
sort_buffer_size = 256
read_buffer_size = 256
read_rnd_buffer_size = 40
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size= 16M
# Try number of CPU's x 2 for thread_concurrency
#thread_concurrency = 2
# Point the following paths to different dedicated disks
#tmpdir = /tmp/
# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
#
#skip-networking
# Replication Master Server (default)
# binary logging is required for replication
#log-bin=mysql-bin
# binary logging format - mixed recommended
binlog_format=mixed
# 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
# ============================================================ #
# =============== Custom server tweaks [start] =============== #
# ============================================================ #
default_storage_engine = InnoDB
innodb_buffer_pool_size = 2G #4G # 8G # Use up to 70-80% of RAM & optionally check if /proc/sys/vm/swappiness is set to 0. Use Tuning Primer or MySQL Tuner to adjust accordingly.
innodb_file_per_table = 1
#--------------------------|
# 2 means log buffer is flushed to OS file cache on every transaction commit.
# The implication of 2 is optimal and improve performance
# if you are not concerning ACID and can lose transactions for last second or two in case of OS crashes
# -------------------------|
innodb_flush_log_at_trx_commit = 2
innodb_flush_method = O_DIRECT
innodb_log_buffer_size = 16M
#---------------------------|
# Delete the ib_logfile0 & ib_logfile1 files in /var/lib/mysql whenever you change this,
# even the first time you set it up, as the default value is 8M.
# Don't go above 256M.
# ref: https://gist.github.com/wh4u/1fafe2bf98f630d7753717b5a8835bca
#---------------------------|
innodb_log_file_size = 256M
innodb_file_per_table=ON
innodb_stats_on_metadata = OFF
innodb_buffer_pool_instances = 8 #(or 1 if innodb_buffer_pool_size < 1GB)
#query_cache_type = 0
#query_cache_size = 0 #(disabling mutex)
#---------------|
# ref: http://techinfobest.com/optimize-mysql-table_open_cache/
# --------------|
table_open_cache=1501
#table_open_cache=30000
open_files_limit=3003
#open_files_limit=19107
#table_open_cache=39390
slow-query-log=0
long_query_time = 1
log-queries-not-using-indexes = 1
[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 = 128M
sort_buffer_size = 128M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
我注意到文件中的一些参数是重复的，因此我注释掉了重复项。例如，table_open_cachemysqld 下有两个位置，一个的值为 256，另一个的值为 39390。
对于性能问题，从来都不是由某一件事引起的。我将写下我所做的所有调整，希望这对其他人也有帮助。每个人的评论都非常有帮助，你们都展示了寻找解决方案的方法。
我按照本指南计算了正确的数字。
mysql> show global status like 'open%';
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| Open_files | 43 |
| Open_streams | 0 |
| Open_table_definitions | 375 |
| Open_tables | 2288 |
| Opened_files | 6842 |
| Opened_table_definitions | 376 |
| Opened_tables | 3286 |
+--------------------------+-------+
mysql> SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE TABLE';
+----------+
| COUNT(*) |
+----------+
| 273 |
+----------+
mysql> show global status like '%Threads_connected%';
+-------------------+-------+
| Variable_name | Value |
+-------------------+-------+
| Threads_connected | 11 |
+-------------------+-------+
Table_open_cache = total_tables*Threads_connected
= 273 * 11
= 3003
table_open_cache=1501
open_files_limit=3003
里克·詹姆斯（Rick James）关于之前的值太大的说法是正确的。
那么以下参数不正确：
sort_buffer_size = 256 (Default value: 262144, as per official documentation)
read_buffer_size = 256 (Better 128K)
read_rnd_buffer_size = 40 (Default Value: 262144, as per official documentation)
reasonable alternatives are:
sort_buffer_size=512K
read_buffer_size=256K
read_rnd_buffer_size=128K
正如威尔逊·豪克建议的那样。
max_connections原来是150，所以我减少到了50。
另外，php-fpm配置需要编辑。
pm.max_children = 50
pm.start_servers = 5
pm.min_spare_servers = 5
pm.max_spare_servers = 35
pm.start_servers= min_spare_servers + (max_spare_servers - min_spare_servers) / 2
changing to
pm.max_children = 25
pm.start_servers = 11
pm.min_spare_servers = 5
pm.max_spare_servers = 17
最好始终遵循官方文档中提供的公式。
所有这些都使内存恢复正常使用。但CPU负载仍然太高。
最后但并非最不重要的一点是，我使用了JetProfiler工具。即使免费版本也有帮助。我发现了那些运行时间太长的查询。很棒的是，jetprofiler 甚至可以为您提供建议，您可以优化查询。
现在htop看起来好多了。
