我在Dual Xeon CPU上运行版本10.0.16-MariaDB-1（Debian GNU / Linux 8.1（jessie）），共有32个内核，128 GB内存。这是一个专用的数据库服务器，最近从Percona数据库服务器迁移过来。我的配置如下所示，
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# DATE: 19-01-2014
# DESCRIPTION: MySQL config
# RAM: 128GB RAM dedicated server
# Connections: 1000 connections
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[mysql]
# CLIENT #
port = 1979
socket = /var/run/mysqld/mysqld.sock
[mysqld]
## Files
back_log = 300
open-files-limit = 8192
#open-files = 1024
# GENERAL #
user = mysql
default-storage-engine = InnoDB
port = 1979
socket = /var/run/mysqld/mysqld.sock
pid-file = /var/run/mysqld/mysql.pid
# DATA STORAGE #
datadir = /var/lib/mysql
# LOGGING #
log-error = /var/log/mysql/mysql-error.log
log-queries-not-using-indexes = 0
slow-query-log = 0
slow-query-log-file = /var/log/mysql/mysql-slow.log
## Per-Thread Buffers * (max_connections) = total per-thread mem usage
thread_stack = 512K #default: 32bit: 192K, 64bit: 256K
sort_buffer_size = 2M #default: 2M, larger may cause perf issues
read_buffer_size = 2M #default: 128K, change in increments of 4K
read_rnd_buffer_size = 2M #default: 256K
join_buffer_size = 2M #default: 128K
binlog_cache_size = 128K #default: 32K, size of buffer to hold TX queries
## total per-thread buffer memory usage: 17664000K = 17.250GB
## Query Cache
query_cache_size = 64M #global buffer
query_cache_limit = 2M #max query result size to put in cache
## Connections
max_connections = 900 #multiplier for memory usage via per-thread buffers
max_connect_errors = 1000 #default: 10
concurrent_insert = 2
connect_timeout = 10 #default -5.1.22: 5, +5.1.22: 10
max_allowed_packet = 32M #max size of incoming data to allow
## Default Table Settings
sql_mode = NO_AUTO_CREATE_USER
## Table and TMP settings
max_heap_table_size = 1G #recommend same size as tmp_table_size
bulk_insert_buffer_size = 1G #recommend same size as tmp_table_size
tmp_table_size = 1G #recommend 1G min
tmpdir = /dev/shm #Recommend using RAMDISK for tmpdir
## Table cache settings
#table_cache = 512 #5.0.x <default: 64>
#table_open_cache = 512 #5.1.x, 5.5.x <default: 64>
query-cache-type = 1
## Thread settings
thread_concurrency = 32 #recommend 2x CPU cores
thread_cache_size = 400 #recommend 5% of max_connections
## InnoDB Plugin Independent Settings
innodb_data_home_dir = /var/lib/mysql
innodb_data_file_path = ibdata1:128M;ibdata2:10M:autoextend
innodb_log_file_size = 768M #64G_RAM+ = 768, 24G_RAM+ = 512, 8G_RAM+ = 256, 2G_RAM+ = 128
innodb_log_files_in_group = 4 #combined size of all logs <4GB. <2G_RAM = 2, >2G_RAM = 4
innodb_buffer_pool_size = 96G #global buffer
innodb_additional_mem_pool_size = 8M #global buffer
innodb_status_file #extra reporting
innodb_file_per_table #enable always
innodb_flush_log_at_trx_commit = 2
innodb_table_locks = 0 #preserve table locks
innodb_log_buffer_size = 128M #global buffer
innodb_lock_wait_timeout = 600
#innodb_thread_concurrency = 0
innodb_commit_concurrency = 8 #recommend 4x num disks
innodb_flush_method = O_DIRECT_NO_FSYNC #O_DIRECT = local/DAS, O_DSYNC = SAN/iSCSI
innodb_support_xa = 0 #recommend 0, disable xa to negate extra disk flush
innodb_fast_shutdown = 1
skip-innodb-doublewrite
skip-host-cache
# skip-name-resolve
## Binlog sync settings
## XA transactions = 1, otherwise set to 0 for best performance
sync_binlog = 0
## TX Isolation
#transaction-isolation = REPEATABLE-READ #REPEATABLE-READ req for ACID, SERIALIZABLE req XA
## Per-Thread Buffer memory utilization equation:
#(read_buffer_size + read_rnd_buffer_size + sort_buffer_size + thread_stack + join_buffer_size + binlog_cache_size) * max_connections
## Replication
#server_id = 1
#log_bin = /var/log/mysql/mysql-bin.log
#log_bin_index = /var/log/mysql/mysql-bin.log.index
#relay_log = /var/log/mysql/mysql-relay-bin
#relay_log_index = /var/log/mysql/mysql-relay-bin.index
#expire_logs_days = 10
#max_binlog_size = 100M
#log_slave_updates = 1
#auto-increment-increment = 2
#auto-increment-offset = 1
## Global Buffer memory utilization equation:
# innodb_buffer_pool_size + innodb_additional_mem_pool_size + innodb_log_buffer_size + key_buffer_size + query_cache_size
long_query_time = 3
innodb_checksum_algorithm=NONE
interactive_timeout = 300
wait_timeout = 40
myisam_repair_threads = 8
myisam-block-size = 8096
innodb_adaptive_hash_index = off
innodb_use_sys_malloc
innodb_sync_array_size = 4
innodb_read_ahead_threshold = 56
innodb_purge_threads = 4
innodb_adaptive_flushing = off
innodb_use_native_aio = off
innodb_random_read_ahead
optimizer_search_depth = 24
table_definition_cache = 400
table_open_cache = 2048
delay-key-write = ALL
innodb_checksum_algorithm = innodb
innodb_write_io_threads = 64
innodb_read_io_threads = 64
thread_pool_size = 16
thread_handling = pool-of-threads
innodb_disable_sort_file_cache
innodb_buffer_pool_instances = 32
innodb_adaptive_hash_index = off
[mysqldump]
quick
quote-names
max_allowed_packet = 128M
我有多台主机连接到服务器并启动查询。我面临的问题是随机数据库服务器停止接受连接。所有连接开始堆积，并在大约3或5秒后恢复正常。当我运行show processlist时，我看到许多连接正在等待connected，但由于数据库服务器停止接受连接，最终连接池变满，不允许进一步连接。
在这个停电期间，我无法看到数据库服务器上发生了什么，因为即使连接已经建立，我也不会给我任何信息。 iostat -d -x 1不会显示磁盘异常，CPU也大多闲置。由于客户端想要打开连接，TCP连接堆积起来，因为他们需要推送数据。
我无法弄清楚这里有什么问题。这是我的数据库，机器或配置特有的东西。我在这里需要一些帮助，找出在哪里以及寻找什么来识别和纠正这个问题。
感谢。
答案 0 :(得分：0)
thread_stack = 512K #default：32位：192K，64位：256K
我没有听说需要超过256K。您是否发现需要512K？与
一起max_connections = 900
您可能需要500MB的流程。 （当然，这不是什么大问题，因为你有128GB的内存。）
回到问题......
使用long_query_time = 1打开slow_log。在下一次出现之后，对slowlog运行pt-query-digest。那里可能会有一些惊喜。请注意，挂起3-5秒暂停的查询将注册为几秒钟，即使它们只需要几毫秒。它仍然存在风险，它无法指出暂停的真正原因。