Doris最大链接数优化

问题背景：

用户在使用Doris的时候，当访问用户过多时会报Reach limit of connections，针对这种情况需要调整Doris最大连接数，具体做法如下。

解决办法：

Session变量设置

SET PROPERTY FOR 'root' 'max_user_connections' = '10000';

在fe.conf添加如下配置并重启

qe_max_connection= 102400
max_connection_scheduler_threads_num=409600

创建库表和插入数据：

CREATE TABLE `test_xxx` (`day` date NOT NULL COMMENT 'default 1980-00-00',`user_type` varchar(20) NULL,`product` varchar(20) NULL,`user_id` varchar(20) NULL,`value` int(11) NULL,`cut` bigint(20) NULL,`cut1` smallint(6) NULL
) ENGINE=OLAP
UNIQUE KEY(`day`, `user_type`, `product`, `user_id`)
COMMENT 'OLAP'
PARTITION BY RANGE(`day`)
(PARTITION p201701 VALUES [('0000-01-01'), ('2017-02-01')),
PARTITION p201702 VALUES [('2017-02-01'), ('2017-03-01')),
PARTITION p201703 VALUES [('2017-03-01'), ('2017-04-01')))
DISTRIBUTED BY HASH(`day`, `user_type`) BUCKETS 1
PROPERTIES (
"replication_allocation" = "tag.location.default: 1",
"is_being_synced" = "false",
"storage_format" = "V2",
"light_schema_change" = "true",
"disable_auto_compaction" = "false",
"enable_single_replica_compaction" = "false"
); mysql>  select * from test_xxx;
+------------+-----------+---------+---------+-------+------+------+
| day        | user_type | product | user_id | value | cut  | cut1 |
+------------+-----------+---------+---------+-------+------+------+
| 2017-02-02 | a         | p_a     | user1   |     1 |    2 |    3 |
+------------+-----------+---------+---------+-------+------+------+
1 row in set (0.03 sec)mysql>

vim max_connect.sql 并写入如下数据

 select * from test_xxx;

执行mysqlslap -h127.0.0.1 -P9030 -uroot --concurrency=3000 --iterations=1 --create-schema=test --query=max_connect.sql ，使用mysqlslap进行压测。
这里可以看到有3000个并发同时提交到Doris，所有SQL正常支持完成。