我已经在一个单独的服务器上配置了mariadb，但是查询仍然需要很长时间才能返回，而且大多数情况下不会返回。
Mariadb版本：10.1.31-1
服务器具有50GB Ram和2200 Ghz*10核
Centos7操作
目标数据库目前有非常大的innodb表，索引不好。除了innodb，没有其他任何表类型。
目前，我正在进行一些嵌套的select查询，并使用insert into或replace into将结果保存到另一个空的克隆数据库中。
例如：
REPLACE INTO db1.table1
SELECT * FROM db0.table1 WHERE ART_ID IN (
SELECT ART_ID FROM db0.table2 WHERE BRA_ID IN (
SELECT BRA_ID FROM db0.table3 WHERE BRAND IN (
SELECT BRAND FROM db0.table4 WHERE ID IN (... bunch of comma seperated ids)
)
)
);
唯一的连接来自本地和/或一个远程连接。
服务器的唯一任务是将大量数据过滤到另一个数据库，而不是web服务器等。
我把/etc/my.cnf文件放在下面。我对这个文件做了很多测试，所以你可能会看到一些无用的补充。
问题是：cnf文件中是否有任何配置丢失；是否有任何其他配置提示等来在合理的时间内运行这些查询。
它工作得更好，但在我更改配置或/和更新服务器之后，一切都变得慢得多。（是的，我在更新数据库版本后也会更新表）
# The MySQL server
[mysqld]
performance_schema=0
bind-address = 0.0.0.0
max_connections = 32
socket = /var/lib/mysql/mysql.sock
skip-external-locking
max_allowed_packet = 1024M
connect_timeout=300
wait_timeout=1200
interactive_timeout=300
key_buffer_size = 2G
bulk_insert_buffer_size=256M
sort_buffer_size = 32M
#read_buffer_size = 8M
#read_rnd_buffer_size = 32M
myisam_sort_buffer_size = 32M
join_buffer_size=32M
#max_heap_table_size= 8G
tmp_table_size=8G
concurrent_insert=2
#external-locking=FALSE
#open_files_limit=50000
default-storage-engine=innodb
innodb_file_per_table=1
#lower_case_table_names=1
# Try number of CPU's*2 for thread_concurrency
innodb_write_io_threads=10
innodb_read_io_threads=20
#innodb_buffer_pool_instances=8
#thread_stack = 1M
#thread_cache_size = -1
innodb_buffer_pool_size = 16G
#query_cache_limit = 1073741824
#query_cache_size = 1073741824
#query_cache_type = 1
query_cache_size=0
query_cache_type=0
#innodb_additional_mem_pool_size = 20M
# Set .._log_file_size to 25 % of buffer pool size
innodb_fast_shutdown=0
#innodb_log_file_size = 1G
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 0
innodb_lock_wait_timeout = 1073741823
innodb_thread_concurrency=0
innodb_commit_concurrency=0
innodb_flush_method=O_DSYNC
innodb_log_compressed_pages = 0
#innodb_flush_neighbors = 0
#innodb_adaptive_hash_index_partitions = 8
log-bin=mysql-bin
server-id = 1
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
[isamchk]
key_buffer = 384M
sort_buffer = 384M
read_buffer = 256M
write_buffer = 256M
[myisamchk]
key_buffer = 384M
sort_buffer = 384M
read_buffer = 256M
write_buffer = 256M
[mysqlhotcopy]
interactive-timeout
我用了percona巫师并合并了建议。
当前的my.cnf如下。
我昨天晚上运行了php应用程序（2018-03-05 22:41:30 UTC），但mysql仍然无法返回任何结果。
应用程序只添加了limit 10000和offset（我不想从头开始，我目前正在跟踪最后一个offset并从该点开始）
目前我正计划删除并重新安装mariadb：(
（这将是情绪反应）
# Generated by Percona Configuration Wizard (http://tools.percona.com/) version REL5-20120208
[mysql]
# CLIENT #
port = 9999
socket = /var/lib/mysql/mysql.sock
[mysqld]
# GENERAL #
port = 9999
user = mysql
default-storage-engine = InnoDB
socket = /var/lib/mysql/mysql.sock
pid-file = /var/lib/mysql/mysql.pid
# MyISAM # - there is no myisam table
key-buffer-size = 32M
myisam-recover-options = FORCE,BACKUP
# SAFETY #
max-allowed-packet = 16M
max-connect-errors = 1000000
skip-name-resolve
# DATA STORAGE #
datadir = /var/lib/mysql/
# BINARY LOGGING #
log-bin = /var/lib/mysql/mysql-bin
expire-logs-days = 14
sync-binlog = 1
# CACHES AND LIMITS #
tmp-table-size = 32M
max-heap-table-size = 32M
query-cache-type = 0
query-cache-size = 0
max-connections = 30
#thread-cache-size = 16
open-files-limit = 65535
table-definition-cache = 1024
table-open-cache = 2048
# INNODB #
innodb-flush-method = O_DIRECT
innodb-log-files-in-group = 2
innodb-log-file-size = 5G
innodb-flush-log-at-trx-commit = 1
innodb-file-per-table = 1
innodb-buffer-pool-size = 42G
innodb-buffer-pool-instances = 42
thread_cache_size=100
innodb_lru_scan_depth=100
innodb_purge_threads=4
innodb_read_io_threads=64
innodb_write_io_threads=64
innodb_thread_concurrency=0
max_seeks_for_key=32
max_write_lock_count=16
thread_concurrency=35
innodb_fast_shutdown=0
innodb_file_per_table=1
default-storage-engine=innodb
concurrent_insert=2
join_buffer_size=32M
tmp_table_size=8G
read_buffer_size = 8M
# LOGGING #
log-error = /var/lib/mysql/mysql-error.log
log-queries-not-using-indexes = 0
slow-query-log = 1
slow-query-log-file = /var/lib/mysql/mysql-slow.log
最佳答案
问题中的my.cnf数据与SHOW GLOBAL VARIABLES；values不匹配。
请使用此链接
https://mariadb.com/kb/en/library/configuring-mariadb-with-mycnf/
以帮助获取准确的匹配值以获得帮助。
那么，对于my.cnf[mysqld]部分，需要考虑的建议包括：
innodb_buffer_pool_size=8G # from > 40G (95% of RAM will not work well)
innodb_lru_scan_depth=100 # from 1024 see refman every second digging too deep
log_warnings=2 # from 1 to include connection errors more detail
max_connect_errors=10 # from 1,000,000 no need to waste a million cycles
thread_cache_size=100 # from 16 CAP per V8 MySQ to be prepared for volume
have_symlink=NO # to protect you server, unless you NEED it
innodb_purge_threads=4 # from 1 to accommodate when needed
innodb_read_io_threads=64 # from 4 see dba.stackexhange.com Q 5666 9/12/11 Rolando
innodb_write_io_threads=64 # from 4 per Rolando to use multi-core
innodb_thrad_concurrency=0 # another part of multi-core enabling
max_seeks_for_key=32 # from huge number, not found in 32, will not be found
max_write_lock_count=16 # give RD opportunity after nn locks
thread_concurrency=35 # to limit concurrent processing load
@Erce，请申请正确的有效的my.cnf。撤销了我重做mysqld部分的提议。
关于mysql - 为专用的mariadb服务器找到正确的配置-适用于庞大的innodb表，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/49094911/