METRICS_TABLES

METRICS_TABLES 表为 metrics_schema 数据库中的每个视图提供 PromQL(Prometheus 查询语言)定义。

USE information_schema; DESC metrics_tables;
+------------+--------------+------+------+---------+-------+ | Field | Type | Null | Key | Default | Extra | +------------+--------------+------+------+---------+-------+ | TABLE_NAME | varchar(64) | YES | | NULL | | | PROMQL | varchar(64) | YES | | NULL | | | LABELS | varchar(64) | YES | | NULL | | | QUANTILE | double | YES | | NULL | | | COMMENT | varchar(256) | YES | | NULL | | +------------+--------------+------+------+---------+-------+

metrics_tables 的字段解释:

  • TABLE_NAME:对应于 metrics_schema 中的表名。
  • PROMQL:监控表的主要原理是将 SQL 映射成 PromQL,并将 Prometheus 结果转换成 SQL 查询结果。这个字段是 PromQL 的表达式模板,查询监控表数据时使用查询条件改写模板中的变量,生成最终的查询表达式。
  • LABELS:监控定义的 label,每一个 label 对应监控表中的一列。SQL 中如果包含对应列的过滤,对应的 PromQL 也会改变。
  • QUANTILE:百分位。对于直方图类型的监控数据,指定一个默认百分位。如果值为 0,表示该监控表对应的监控不是直方图。
  • COMMENT:对这个监控表的注释。
SELECT * FROM metrics_tables LIMIT 5\G
*************************** 1. row *************************** TABLE_NAME: abnormal_stores PROMQL: sum(pd_cluster_status{ type=~"store_disconnected_count|store_unhealth_count|store_low_space_count|store_down_count|store_offline_count|store_tombstone_count"}) LABELS: instance,type QUANTILE: 0 COMMENT: *************************** 2. row *************************** TABLE_NAME: etcd_disk_wal_fsync_rate PROMQL: delta(etcd_disk_wal_fsync_duration_seconds_count{$LABEL_CONDITIONS}[$RANGE_DURATION]) LABELS: instance QUANTILE: 0 COMMENT: The rate of writing WAL into the persistent storage *************************** 3. row *************************** TABLE_NAME: etcd_wal_fsync_duration PROMQL: histogram_quantile($QUANTILE, sum(rate(etcd_disk_wal_fsync_duration_seconds_bucket{$LABEL_CONDITIONS}[$RANGE_DURATION])) by (le,instance)) LABELS: instance QUANTILE: 0.99 COMMENT: The quantile time consumed of writing WAL into the persistent storage *************************** 4. row *************************** TABLE_NAME: etcd_wal_fsync_total_count PROMQL: sum(increase(etcd_disk_wal_fsync_duration_seconds_count{$LABEL_CONDITIONS}[$RANGE_DURATION])) by (instance) LABELS: instance QUANTILE: 0 COMMENT: The total count of writing WAL into the persistent storage *************************** 5. row *************************** TABLE_NAME: etcd_wal_fsync_total_time PROMQL: sum(increase(etcd_disk_wal_fsync_duration_seconds_sum{$LABEL_CONDITIONS}[$RANGE_DURATION])) by (instance) LABELS: instance QUANTILE: 0 COMMENT: The total time of writing WAL into the persistent storage 5 rows in set (0.00 sec)