我已将数据库表从 InnoDB 转换为 TokuDB，我注意到使用 TokuDB，读取使用了太多的 CPU。这是为什么？
更具体地说，带有 TokuDB 表的服务器是带有 InnoDB 的服务器的从属服务器，InnoDB 是 PXC 的一部分。从服务器只使用常规的 percona 服务器而不是 PXC。但是从站似乎使用了太多的CPU，我不知道为什么？
下面是我的 my.cnf 配置:
[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock
[mysqld_safe]
thp-setting=never
socket = /var/run/mysqld/mysqld.sock
nice = 0
flush_caches
numa_interleave
core-file-size = unlimited
open_files_limit = 1024
[mysqld]
back_log = 65535
bind-address = 0.0.0.0
binlog_format = ROW
character_set_server = utf8
collation_server = utf8_general_ci
core_file
basedir = /usr
datadir = /var/lib/mysql
#default_storage_engine = InnoDB
enforce-gtid-consistency = 1
expand_fast_index_creation = 1
expire_logs_days = 7
gtid_mode = ON
innodb_autoinc_lock_mode = 2
innodb_buffer_pool_instances = 1
innodb_buffer_pool_populate = 1
innodb_buffer_pool_size = 512M
innodb_data_file_path = ibdata1:64M;ibdata2:64M:autoextend
innodb_file_format = Barracuda
innodb_file_per_table
innodb_force_recovery = 1
innodb_flush_log_at_trx_commit = 2
innodb_flush_method = O_DIRECT
innodb_io_capacity = 1600
innodb_large_prefix
innodb_locks_unsafe_for_binlog = 1
innodb_log_file_size = 64M
innodb_print_all_deadlocks = 1
innodb_read_io_threads = 64
innodb_stats_on_metadata = FALSE
innodb_support_xa = FALSE
innodb_write_io_threads = 64
lc-messages-dir = /usr/share/mysql
log-bin = mysqld-bin
log-queries-not-using-indexes
log-slave-updates
long_query_time = 1
master_info_repository = TABLE
max_allowed_packet = 64M
max_connect_errors = 4294967295
max_connections = 2500
max_user_connections = 2550
min_examined_row_limit = 1000
open_files_limit = 1024
port = 3306
relay_log_info_repository = TABLE
relay-log-recovery = TRUE
relay-log-recovery = 1
skip-external-locking
skip-name-resolve
slave_parallel_workers = 8
slow_query_log = 1
slow_query_log_timestamp_always = 1
socket = /var/run/mysqld/mysqld.sock
table_open_cache = 4096
thread_cache = 1024
tmpdir = /srv/tmp
transaction_isolation = REPEATABLE-READ
updatable_views_with_limit = 0
user = mysql
wait_timeout = 60
server-id = 2
# TokuDB fine tuning
default_storage_engine = TokuDB
tokudb_analyze_time = 5
#tokudb_cache_size = 6G
tokudb_directio = 1
tokudb_commit_sync = 0
tokudb_fsync_log_period = 1000
tokudb_load_save_space =1
tokudb_alter_print_error=0
tokudb_block_size = 4MB
tokudb_bulk_fetch = 1
tokudb_disable_slow_alter = 1
tokudb_last_lock_timeout = empty
tokudb_row_format = tokudb_quicklz
#tokudb_data_dir = /var/lib/tokudb
[mysqldump]
quick
quote-names
max_allowed_packet = 16M
[mysql]
#no-auto-rehash # faster start of mysql but no tab completition
[isamchk]
key_buffer = 16M
!includedir /etc/mysql/conf.d/
当 tokudb_cache_size 最初设置为总 RAM 的 80% 时，我们的监控系统 xymon 报告以下复制消息。
2016-02-25 16:42:04 9604 [Warning] Neither --relay-log nor --relay-log-index were used; so replication may break when this MySQL server acts as a slave and has his hostname changed!! Please use '--relay-log=db-kdb-slave-6-relay-bin' to avoid this problem.
2016-02-25 16:42:05 9604 [Warning] Recovery from master pos 552554502 and file mysqld-bin.001163. Previous relay log pos and relay log file had been set to 552554714, ./db-kdb-slave-6-relay-bin.002933 respectively.
2016-02-25 16:42:05 9604 [Warning] Storing MySQL user name or password information in the master info repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START SLAVE; see the 'START SLAVE Syntax' in the MySQL Manual for more information.
------有关运行 InnoDB 的主服务器和 PXC 部分的更多信息------------
## Results from top
top - 10:05:12 up 14 days, 7:56, 2 users, load average: 2.16, 2.31, 2.39
Tasks: 413 total, 1 running, 412 sleeping, 0 stopped, 0 zombie
%Cpu(s): 8.9 us, 0.6 sy, 0.0 ni, 89.9 id, 0.3 wa, 0.0 hi, 0.2 si, 0.0 st
KiB Mem: 65704012 total, 63553216 used, 2150796 free, 169832 buffers
KiB Swap: 975868 total, 809892 used, 165976 free. 16304268 cached Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2485 mysql 20 0 60.146g 0.045t 2.612g S 314.9 73.3 27762:43 mysqld
## disk info
george@db-erp-3:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 32G 8.0K 32G 1% /dev
tmpfs 6.3G 1.2M 6.3G 1% /run
/dev/sda2 274G 2.1G 258G 1% /
none 4.0K 0 4.0K 0% /sys/fs/cgroup
none 5.0M 0 5.0M 0% /run/lock
none 32G 0 32G 0% /run/shm
none 100M 0 100M 0% /run/user
/dev/nvme0n1p1 1.1T 542G 503G 52% /srv
na1:/vol/yphome 4.5T 3.7T 875G 82% /net/account
## Memory info
george@db-erp-3:~$ free -g
total used free shared buffers cached
Mem: 62 60 2 0 0 15
-/+ buffers/cache: 44 17
Swap: 0 0 0
george@db-erp-3:~$
## Database info
+--------------------+----------------------+
| Data Base Name | Data Base Size in MB |
+--------------------+----------------------+
| information_schema | 0.00976563 |
| dberp | 347143.32031250 |
| mysql | 2.11562061 |
| performance_schema | 0.00000000 |
+--------------------+----------------------+
4 rows in set (0.13 sec)
+--------------------+----------------------+------------------+
| Data Base Name | Data Base Size in MB | Free Space in MB |
+--------------------+----------------------+------------------+
| information_schema | 0.00976563 | 0.00000000 |
| dberp | 347143.32031250 | 6270.00000000 |
| mysql | 2.11562061 | 4.00199127 |
| performance_schema | 0.00000000 | 0.00000000 |
+--------------------+----------------------+------------------+
4 rows in set (0.03 sec)
最佳答案
您的 CPU 读取速度会更高，因为 TokuDB 数据需要解压才能使用。此外，如果该从属设备正在处理来自主设备的任何事件，那么它也会对插入/更新/删除事件进行压缩。
几个想法。 1.减小tokudb_block_size的值。虽然 4MB 非常适合压缩，但这意味着您的点查询需要解压缩比必须解压缩的数据多得多的数据。尝试使用 256KB，看看 CPU 和性能如何变化。您可能需要重建您的从站才能轻松完成此任务(我现在距离在 TokuDB 工作还有一年多了)。 2. 查看您的 tokudb_cache_size。它默认为 RAM 的 50%，但如果该服务器上没有其他内容，您应该将其提高到 75% 到 80% 之间。这意味着更少的读取和解压缩，因为更多数据将存储在缓存中。
关于MySQL TokuDB 引擎使用过多 CPU，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35752540/