Impala coordinator Startup flags
Learn about Impala coordinator startup flags used to create and configure query logging tables during startup.
On startup, each Impala coordinator runs an SQL statement to create the query logging
tables. The following table lists the Impala startup coordinator flags that you can
configure:
Name | Data Type | Default | Description |
---|---|---|---|
cluster_id | string | Specifies an identifier string that uniquely represents this cluster. This
identifier is included in both the tables and is used as a table partition for the
sys.impala_query_log table. |
|
query_log_shutdown_timeout_s | number (seconds) | 30 | Hidden flag. Number of seconds to wait for the queue of completed queries to be carried into the query history table before timing out and continuing the shutdown process.The query history table drain process runs after the shutdown process completes, therefore the max shutdown time is extended by the value specified in this flag. |
workload_mgmt_user | string | impala | Specifies the user that will be used to insert records into the query history table. |
query_log_write_interval_s | number (seconds) | 300 | Number of seconds to wait before inserting completed queries into the query history table. Allows for batching inserts to help avoid small files. |
query_log_max_queued | number | 3000 | Maximum number of completed queries that can be queued before they are
written to the query history table.This flag operates independently of the
query_log_write_interval_m flag. If the number of queued
records reaches this value, the records will be written to the query log table no
matter how much time has passed since the last write.A value of 0 indicates no
maximum number of queued records. |
query_log_max_sql_length | number | 16777216 | Maximum length of a SQL statement that will be recorded in the completed queries table. If a SQL statement with a length longer than this specified value is executed, the SQL inserted into the completed queries table will be trimmed to this length. Any characters that require escaping will have their backslash character counted towards this limit. |
query_log_max_plan_length | number | 16777216 | Maximum length of the SQL query plan that will be recorded in the completed queries table. If a query plan has a length longer than this value, the plan inserted into the completed queries table will be trimmed to this length. Any characters that require escaping will have their backslash character counted towards this limit. |
query_log_request_pool | string | Specifies a pool or queue used by the queries that insert into the query log table. Empty value causes no pool to be set. | |
query_log_dml_exec_timeout_s | number | 120 | Specifies the value of the EXEC_TIME_LIMIT_S query option on the DML that
inserts records into the sys.impala_query_log table. |