file_cache_statistics

Overview

Used to view the metric information related to data cache on each BE node. The metric information is sourced from the monitoring metrics related to BE's data cache.

:::tip Tip This system table is supported from versions 2.1.6 and 3.0.2. :::

Database

information_schema

Table Information

:::info Note

Doris different version may have different metrics

:::

2.1.x Metrics

Only important metrics are listed.

• normal_queue_curr_elements

  Number of File Blocks currently in the cache.

• normal_queue_max_elements

  Maximum number of File Blocks allowed in the cache.

• normal_queue_curr_size

  Current cache size.

• normal_queue_max_size

  Maximum cache size allowed.

• hits_ratio

  Overall cache hit ratio since BE startup. Range 0-1.

• hits_ratio_5m

  Cache hit ratio in the last 5 minutes. Range 0-1.

• hits_ratio_1h

  Cache hit ratio in the last 1 hour. Range 0-1.

3.0.x Metrics

TODO

Examples

1. Query all cache metrics

   mysql> select * from information_schema.file_cache_statistics;
   +-------+---------------+----------------------------+----------------------------+--------------------+
   | BE_ID | BE_IP         | CACHE_PATH                 | METRIC_NAME                | METRIC_VALUE       |
   +-------+---------------+----------------------------+----------------------------+--------------------+
   | 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | normal_queue_curr_elements |               1392 |
   | 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | normal_queue_curr_size     |          248922234 |
   | 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | normal_queue_max_elements  |             102400 |
   | 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | normal_queue_max_size      |        21474836480 |
   | 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | hits_ratio                 | 0.8539634687001242 |
   | 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | hits_ratio_1h              |                  0 |
   | 10003 | 172.20.32.136 | /mnt/output/be/file_cache/ | hits_ratio_5m              |                  0 |
   +-------+---------------+----------------------------+----------------------------+--------------------+

2. Query cache hit ratio and sort by hit ratio

   select * from information_schema.file_cache_statistics where METRIC_NAME = "hits_ratio" order by METRIC_VALUE desc;