xsfeng-zodiac
commented
10 months ago Here are some metrics we are interested in (from @weili-db):
the high level query execution plan
the running duration
the walltime of the query running time
the rows scanned
total keys scanned caused by LSM tree’s depth for keep all GC record
the rows filtered out
the rows returned
the request unit for 7.1 multi-tenant env
the IO time (might be stretch, optional)
the CPU time (might be stretch, optional)
the lock waiting time (might be stretch, optional)
Enhancement
Currently there are three types of TiDB query logging: slow query log, general log and audit log. General logs keeps the general information within query execution context, e.g. username, connection id, startTs, forUpdateTs, schemaVersion, etc. Slow query log keeps all information within general log, as well as query level performance related metrics, e.g. # of mvcc version being scanned, # of rows actually read, lock wait time, TiKV cpu time etc.
Audit log is out of scope here so won't be discussed.
We hope to understand the query performance better and predict of query impacts under organic data growth, thus we are hoping to have query metrics in slow queries logged for all queries for data analysis.