important metrics in stmgr are missing after refactoring

[nlu90]

In the commit 557c980, the stmgr is refactored and some important metrics are omitted.

• METRIC_DATA_TUPLES_FROM_STMGRS
• METRIC_ACK_TUPLES_FROM_STMGRS
• METRIC_FAIL_TUPLES_FROM_STMGRS
• METRIC_FAIL_TUPLES_FROM_STMGRS
• METRIC_BYTES_FROM_STMGRS
• METRIC_DATA_TUPLES_TO_INSTANCES
• METRIC_BYTES_TO_INSTANCES
• METRIC_BYTES_FROM_INSTANCES
• METRIC_DATA_TUPLES_TO_INSTANCES_LOST
• METRIC_BYTES_TO_INSTANCES_LOST
• METRIC_TIME_SPENT_BACK_PRESSURE_AGGR
• METRIC_TIME_SPENT_BACK_PRESSURE_INIT

This is causing problems for monitoring and debugging the stmgr.

[objmagic]

would like to have these metrics back. It will help us debugging stream manager.

[huijunw]

how are these metrics collected? I did not find them in the metrics_sinks.yaml/tmaster-metrics-type

[nlu90]

@huijunw Those metrics are calculated on the run. You can check the commit I mentioned to see how they are calculated.