User Resource Monitoring
In the multi-tenant management framework, you can query the real-time usage of all user resources (including the memory, number of CPU cores, storage space, temporary space, operator spilling space, and I/Os) in real time through the system views PG_TOTAL_USER_RESOURCE_INFO and PGXC_TOTAL_USER_RESOURCE_INFO and the function GS_WLM_USER_RESOURCE_INFO. You can also query the system catalog GS_WLM_USER_RESOURCE_HISTORY and system view PGXC_WLM_USER_RESOURCE_HISTORY for the historical usage of user resources.
Precautions
- The CPU, I/O, and memory usage of all jobs on fast and slow lanes (simple jobs on fast lanes and complex jobs on slow lanes) can be monitored.
- Currently, the memory and CPU usage of fast track jobs are not controlled. When the fast lane jobs occupy a large number of resources, the used resources may exceed the resource limit.
- In the DN monitoring view, I/O, memory, and CPU display the resource usage and limits of resource pools.
- In the CN monitoring view, I/O, memory, and CPU display the total resource usage and limit of all DN resource pools in the cluster.
- The DN monitoring information is updated every 5 seconds. CNs collect monitoring information from DNs every 5 seconds. Because each instance updates or collects user monitoring information independently, the monitoring information update time on each instance may be different.
- The auxiliary thread automatically invokes the persistence function every 30 seconds to make user monitoring data persistent. So, normally, you don't have to do this.
- When there are a large number of users and a large cluster, querying such real-time views will cause network latency due to the real-time communication overhead between CNs and DNs.
- Resources are not monitored for an initial administrator.
Procedure
- Query all users' resource quotas and real-time resource usage.
1
SELECT * FROM PG_TOTAL_USER_RESOURCE_INFO;
The result view is as follows:
username | used_memory | total_memory | used_cpu | total_cpu | used_space | total_space | used_temp_space | total_temp_space | used_spill_space | total_spill_space | read_kbytes | write_kbytes | read_counts | write_counts | read_speed | write_speed | send_speed | recv_speed -----------------------+-------------+--------------+----------+-----------+------------+-------------+-----------------+------------------+------------------+-------------------+-------------+--------------+-------------+--------------+------------+-------------+------------+------------ perfadm | 0 | 0 | 0 | 0 | 0 | -1 | 0 | -1 | 0 | -1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 usern | 0 | 17250 | 0 | 48 | 0 | -1 | 0 | -1 | 0 | -1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 (2 rows)
The I/O resource monitoring fields (read_kbytes, write_kbytes, read_counts, write_counts, read_speed, and write_speed) can be available only when the GUC parameter described in enable_user_metric_persistent is enabled.
For details about each column, see PG_TOTAL_USER_RESOURCE_INFO.
- Query a user's resource quota and real-time resource usage.
1
SELECT * FROM GS_WLM_USER_RESOURCE_INFO('username');
The query result is as follows:
userid | used_memory | total_memory | used_cpu | total_cpu | used_space | total_space | used_temp_space | total_temp_space | used_spill_space | total_spill_space | read_kbytes | write_kbytes | read_counts | write_counts | read_speed | write_speed | send_speed | recv_speed --------+-------------+--------------+----------+-----------+------------+-------------+-----------------+------------------+------------------+-------------------+-------------+--------------+-------------+--------------+------------+-------------+------------+------------ 16407 | 18 | 1655 | 6 | 19 | 13787176 | -1 | 0 | -1 | 0 | -1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 (1 row)
- Query all users' resource quotas and historical resource usage.
1
SELECT * FROM GS_WLM_USER_RESOURCE_HISTORY;
The query result is as follows:
username | timestamp | used_memory | total_memory | used_cpu | total_cpu | used_space | total_space | used_temp_space | total_temp_space | used_spill_space | total_spill_space | read_kbytes | write_kbytes | read_counts | write_counts | read_speed | write_speed | send_speed | recv_speed -----------------------+-------------------------------+-------------+--------------+----------+-----------+------------+-------------+-----------------+------------------+------------------+-------------------+-------------+--------------+-------------+--------------+-------------+-------------+------------+------------ usern | 2020-01-08 22:56:06.456855+08 | 0 | 17250 | 0 | 48 | 0 | -1 | 0 | -1 | 88349078 | -1 | 45680 | 34 | 5710 | 8 | 320 | 0 | 0 | 0 userg | 2020-01-08 22:56:06.458659+08 | 0 | 15525 | 33.48 | 48 | 0 | -1 | 0 | -1 | 110169581 | -1 | 17648 | 23 | 2206 | 5 | 123 | 0 | 0 | 0 userg1 | 2020-01-08 22:56:06.460252+08 | 0 | 13972 | 33.48 | 48 | 0 | -1 | 0 | -1 | 136106277 | -1 | 17648 | 23 | 2206 | 5 | 123 | 0 | 0 | 0
For the system catalog GS_WLM_USER_RESOURCE_HISTORY, data in the PG_TOTAL_USER_RESOURCE_INFO view is periodically saved to historical tables only when the GUC parameter enable_user_metric_persistent is enabled.
For details about each column, see GS_WLM_USER_RESOURCE_HISTORY.
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