Defined a new broker metric for total query processing time

[navina]

What does this PR do?

Defined a new broker metric for total query processing time and added metric to broker.yaml

Tags to include: observability , release notes

Release Notes:

Includes a new broker timer type metric - queryTotalTimeMs

[navina]

Review pls : @npawar

[kishoreg]

How is this different from the totaltimems that we have today?

[navina]

How is this different from the totaltimems that we have today?

Are you referring to BrokerQueryPhase.QUERY_EXECUTION metric? It is currently defined as:

_brokerMetrics.addPhaseTiming(rawTableName, BrokerQueryPhase.QUERY_EXECUTION,
        executionEndTimeNs - routingEndTimeNs);

So, it is not the total query processing time. Total query time should start from the request compilation phase and all the way to the end.

[navina]

@npawar can you merge this PR?