[STORM-200] Proposal for Multilang's Metrics feature

• Type: New Feature
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.9.3
• Component/s: storm-multilang
• Assignee: DashengJu
• Reporter: DashengJu
• Created: 28/Jan/14 05:32
• Updated: 05/Oct/15 02:56
• Resolved: 01/Jul/14 20:43

Description

Storm 0.9.0.1 exposes a metrics interface to report summary statistics across the full topology. We can build our own metric, and build metrics consumer to use those statistics.

But when we use Multilang(ie. Python), we can not use this feature. So we want to summit a proposal for multilang's metrics.

The specifics of the proposal:
1. The main idea is: when user want to add a metric statistics in multilang(python) bolt，
a) he need first create a metric object and register in ShellBolt's sub-class,
b) then update the metric in Python bolt process through RPC call.

2. In Metrics API:
a) extend IMetric interface add a method for RPC call：public void updateMetricFromRPC(List<Object> params);
b) modify IMetric implements, to support updateMetricFromRPC;

3. In ShellBolt，
a) we have a Map<String, IMetric> to hold user's registered metrics object；
b) we have a method registerMetric(String name, T metric) for user to register their metris object;
c) we have a method handleMetrics(Map action) to handle RPC call from Python process；

4) In Multilang protocol: add a command "metrics" for shell process to make RPC call. The protocol is:

{"command":"metrics", "name":"metric-registerd-name", "params":["param-1", param-2]}

5) In storm.py：add rpcMetrics(name, params), user can update remote metric through this RPC call.

any suggestions?