CLUSTER_SYSTEMINFO
内核参数表 CLUSTER_SYSTEMINFO 用于查询集群所有实例所在服务器的内核配置信息。目前支持查询 sysctl 的信息。
USE information_schema;
DESC cluster_systeminfo;
+-------------+--------------+------+------+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------+--------------+------+------+---------+-------+
| TYPE | varchar(64) | YES | | NULL | |
| INSTANCE | varchar(64) | YES | | NULL | |
| SYSTEM_TYPE | varchar(64) | YES | | NULL | |
| SYSTEM_NAME | varchar(64) | YES | | NULL | |
| NAME | varchar(256) | YES | | NULL | |
| VALUE | varchar(128) | YES | | NULL | |
+-------------+--------------+------+------+---------+-------+
6 rows in set (0.00 sec)
字段解释：
TYPE：对应于节点信息表information_schema.cluster_info中的TYPE字段，可取值为tidb，pd和tikv。INSTANCE：对应于节点信息表information_schema.cluster_info中的INSTANCE字段。SYSTEM_TYPE：系统类型，目前可以查询的系统类型有system。SYSTEM_NAME：目前可以查询的SYSTEM_NAME为sysctl。NAME：sysctl对应的配置名。VALUE：sysctl对应配置项的值。
查询集群所有服务器的内核版本示例如下：
SELECT * FROM cluster_systeminfo WHERE name LIKE '%kernel.osrelease%'
+------+-------------------+-------------+-------------+------------------+----------------------------+
| TYPE | INSTANCE | SYSTEM_TYPE | SYSTEM_NAME | NAME | VALUE |
+------+-------------------+-------------+-------------+------------------+----------------------------+
| tidb | 172.16.5.40:4008 | system | sysctl | kernel.osrelease | 3.10.0-862.14.4.el7.x86_64 |
| pd | 172.16.5.40:20379 | system | sysctl | kernel.osrelease | 3.10.0-862.14.4.el7.x86_64 |
| tikv | 172.16.5.40:21150 | system | sysctl | kernel.osrelease | 3.10.0-862.14.4.el7.x86_64 |
+------+-------------------+-------------+-------------+------------------+----------------------------+