From gpcc_queries_history table, certain records missing data from application_name column.

Products

• VMware Tanzu Data

Issue/Introduction

When running greenplum command center, greenplum metrics collector will collect each query info from shared memory and save it into greenplum command center, into gpmetrics.gpcc_queries_history table. Sometimes user may found certain records in gpcc_queries_history table has empty value for "application_name" column.

Environment

GPCC 6.x
GPCC 7.x

Cause

When collect query info, the main content of the query is collected by metrics collector, from shared memory. Besides that, GPCC collect "application_name" from pg_stat_activity view, with the interval of 1min. If some query end quickly, it end before gpcc could collect the "application_name" from pg_stat_acitivy view, the column for this query in gpcc_queries_history table will be empty.

Resolution

Currently it's an architectural limitation, no workaround is available. GPCC R&D team may find a better way to avoid this limit.