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https://issues.apache.org/jira/browse/STORM-2153?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15589768#comment-15589768
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P. Taylor Goetz commented on STORM-2153:
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One concern I have with having nimbus as the destination of aggregated metrics, 
is nimbus HA. If a new nimbus becomes leader, presumably all metrics will be 
lost or reset to stale values, unless there is some sort of replication.

Would a "metrics store" need to be HA? I would probably argue that it isn't, 
provided the reporters handle a metrics store outage gracefully without 
affecting performance (since the reporter threads are not on the critical path 
this wouldn't be too hard).

I also like the idea of doing the aggregation at the "metrics store" level. 
That would simplify things since all metrics reporters could push values to 
that store without doing any intermediate aggregation.

(I'm using scare quotes around "metrics store" because it is starting to sound 
like we are talking about a new service/daemon.)

> New Metrics Reporting API
> -------------------------
>
>                 Key: STORM-2153
>                 URL: https://issues.apache.org/jira/browse/STORM-2153
>             Project: Apache Storm
>          Issue Type: Improvement
>            Reporter: P. Taylor Goetz
>
> This is a proposal to provide a new metrics reporting API based on [Coda 
> Hale's metrics library | http://metrics.dropwizard.io/3.1.0/] (AKA 
> Dropwizard/Yammer metrics).
> h2. Background
> In a [discussion on the dev@ mailing list | 
> http://mail-archives.apache.org/mod_mbox/storm-dev/201610.mbox/%3ccagx0urh85nfh0pbph11pmc1oof6htycjcxsxgwp2nnofukq...@mail.gmail.com%3e]
>   a number of community and PMC members recommended replacing Storm’s metrics 
> system with a new API as opposed to enhancing the existing metrics system. 
> Some of the objections to the existing metrics API include:
> # Metrics are reported as an untyped Java object, making it very difficult to 
> reason about how to report it (e.g. is it a gauge, a counter, etc.?)
> # It is difficult to determine if metrics coming into the consumer are 
> pre-aggregated or not.
> # Storm’s metrics collection occurs through a specialized bolt, which in 
> addition to potentially affecting system performance, complicates certain 
> types of aggregation when the parallelism of that bolt is greater than one.
> In the discussion on the developer mailing list, there is growing consensus 
> for replacing Storm’s metrics API with a new API based on Coda Hale’s metrics 
> library. This approach has the following benefits:
> # Coda Hale’s metrics library is very stable, performant, well thought out, 
> and widely adopted among open source projects (e.g. Kafka).
> # The metrics library provides many existing metric types: Meters, Gauges, 
> Counters, Histograms, and more.
> # The library has a pluggable “reporter” API for publishing metrics to 
> various systems, with existing implementations for: JMX, console, CSV, SLF4J, 
> Graphite, Ganglia.
> # Reporters are straightforward to implement, and can be reused by any 
> project that uses the metrics library (i.e. would have broader application 
> outside of Storm)
> As noted earlier, the metrics library supports pluggable reporters for 
> sending metrics data to other systems, and implementing a reporter is fairly 
> straightforward (an example reporter implementation can be found here). For 
> example if someone develops a reporter based on Coda Hale’s metrics, it could 
> not only be used for pushing Storm metrics, but also for any system that used 
> the metrics library, such as Kafka.
> h2. Scope of Effort
> The effort to implement a new metrics API for Storm can be broken down into 
> the following development areas:
> # Implement API for Storms internal worker metrics: latencies, queue sizes, 
> capacity, etc.
> # Implement API for user defined, topology-specific metrics (exposed via the 
> {{org.apache.storm.task.TopologyContext}} class)
> # Implement API for storm daemons: nimbus, supervisor, etc.
> h2. Relationship to Existing Metrics
> This would be a new API that would not affect the existing metrics API. Upon 
> completion, the old metrics API would presumably be deprecated, but kept in 
> place for backward compatibility.
> Internally the current metrics API uses Storm bolts for the reporting 
> mechanism. The proposed metrics API would not depend on any of Storm's 
> messaging capabilities and instead use the [metrics library's built-in 
> reporter mechanism | 
> http://metrics.dropwizard.io/3.1.0/manual/core/#man-core-reporters]. This 
> would allow users to use existing {{Reporter}} implementations which are not 
> Storm-specific, and would simplify the process of collecting metrics. 
> Compared to Storm's {{IMetricCollector}} interface, implementing a reporter 
> for the metrics library is much more straightforward (an example can be found 
> [here | 
> https://github.com/dropwizard/metrics/blob/3.2-development/metrics-core/src/main/java/com/codahale/metrics/ConsoleReporter.java].
> The new metrics capability would not use or affect the ZooKeeper-based 
> metrics used by Storm UI.
> h2. Relationship to JStorm Metrics
> [TBD]
> h2. Target Branches
> [TBD]
> h2. Performance Implications
> [TBD]
> h2. Metrics Namespaces
> [TBD]
> h2. Metrics Collected
> *Worker*
> || Namespace || Metric Type || Description ||
> *Nimbus*
> || Namespace || Metric Type || Description ||
> *Supervisor*
> || Namespace || Metric Type || Description ||
> h2. User-Defined Metrics
> [TBD]



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