mysql

###优化 ####java_jdbc batch慢 innodb_flush_log_at_trx_commit = 0

1. 1InnoDB InnoDB will flush (fsync) the transaction logs to the disk at each commit
2. 0the log is only written to the log file and the log file flushed to disk approximately once per second
3. the log is written to the log file at each commit, but the log file is only flushed to disk approximately once per second.
4. 默认为1或者不开启

####连接数不够 max_connections = 1000

SELECT @@MAX_CONNECTIONS;

###常用命令