Querying Workload Manager Record Data
The gp_wlm_records table contains a record of events describing where, why, and how the gpdb_record action was triggered by a rule on the Greenplum cluster.
The gp_wlm_records table is created in the postgres database by default. A different database can be specified at installation time with with the --dbname-records installation option.
The table has the following structure:
| Column | Type |
|---|---|
| time | text |
| state | text |
| ident | text |
| hostname | text |
| query_start | text |
| message | text |
| pid | integer |
| session_id | integer |
| gpdb_segment_role | text |
| usename | text |
| current_query | text |
| rule | text |
| context_args | text |
The primary identifier of each entry in the table is the ident column. This column stores a unique identifier that represents a specific rule that triggered on a specific node in the cluster. If a rule triggers on more than one node in the cluster at the same time, each node is treated as a separate event and receives a unique identifier.
Following are two sample entries from the gp_wlm_records table. In this example, a rule was created to track when a query runs for more than 120 seconds:
=# \x on
Expanded display is on.
=# select * from gp_wlm_records;
-[ RECORD 1 ]-----+-----------------------------------------------------------------------------------------
time | Fri Jun 17 14:30:27 2016
state | BEGIN
ident | 36b3369d-0be8-4d98-b116-6d55f1caf122
hostname | sdw2
query_start | 2016-06-17 14:28:24.162044-07
message | Query exceeds 120 seconds.
pid | 98885
session_id | 1112
gpdb_segment_role | GPDB_SEGMENT
usename | gpadmin
current_query | delete from test where f1();
rule | gpdb_record(message="Query exceeds 120 seconds.") when session_id:host:pid:runtime > 120
context_args | runtime=121
-[ RECORD 2 ]-----+-----------------------------------------------------------------------------------------
time | Fri Jun 17 14:31:07 2016
state | END
ident | 36b3369d-0be8-4d98-b116-6d55f1caf122
hostname |
query_start |
message |
pid |
session_id |
gpdb_segment_role |
usename |
current_query |
rule |
context_args |
In the above example, the state column represents when a query began triggering a rule on a given node and when it stopped. The hostname column stores the host on which the rule triggered.