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https://issues.apache.org/jira/browse/HBASE-18409?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16129837#comment-16129837
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Josh Elser commented on HBASE-18409:
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Hi, [~macmaster]! Mighty nice patch you've put together here.
Isolating the metrics aggregation behind the new hbase-metrics API is a great
idea, IMO.
{code}
+ /////// Other Bases ///////
...
+ /////// Other Bases ///////
{code}
Maybe tone these down? :) Just a leading comment character would be sufficient
{code}
+ this.regionStats = new HashMap<String, RegionStats>();
+ this.cacheDroppingExceptions = new HashMap<String, MutableFastCounter>();
{code}
You can omit the types on the RHS. The bare diamond operator is sufficient.
{code}
+ @VisibleForTesting
+ protected final Map<String, RegionStats> regionStats;
+ @VisibleForTesting
+ protected final Map<String, MutableFastCounter> cacheDroppingExceptions;
{code}
These were ConcurrentHashMaps above. Are we sure that we don't need the
concurrency-safety now?
{code}
+ private final String POOL_EXECUTOR_ACTIVE_KEY = "executorPoolActiveThreads";
+ private final String POOL_EXECUTOR_ACTIVE_DESC = "number of active threads
in the executor pool";
+ private final String POOL_META_ACTIVE_KEY = "metaPoolActiveThreads";
+ private final String POOL_META_ACTIVE_DESC = "number of active threads in
the meta pool";
{code}
These are net-new metrics? Should they be spun out into a different JIRA issue
(we try to limit one "thing" per JIRA issue).
FYI [~stack], I think you had done a review on the hbase-metrics API patch when
Enis brought it in. Thought you might be interested in this one too.
> Migrate Client Metrics from codahale to hbase-metrics
> -----------------------------------------------------
>
> Key: HBASE-18409
> URL: https://issues.apache.org/jira/browse/HBASE-18409
> Project: HBase
> Issue Type: Improvement
> Components: Client, java, metrics
> Affects Versions: 3.0.0
> Reporter: Ronald Macmaster
> Labels: newbie
> Fix For: 3.0.0
>
> Attachments:
> 0001-HBASE-18409-MetricsConnection-client-metrics-migration.patch,
> 0002-HBASE-18409-MetricsConnection-client-metrics-migrati.patch
>
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> Currently, the metrics for hbase-client are tailored for reporting via a
> client-side JMX server.
> The MetricsConnection handles the metrics management and reporting via the
> metrics platform from codahale.
> This approach worked well for hbase-1.3.1 when the metrics platform was still
> relatively young, but it could be improved by using the new
> hbase-metrics-api.
> Now that we have an actual hbase-metrics-api that master, regionserver,
> zookeeper, and other daemons use, it would be good to also allow the client
> to leverage the metrics-api.
> Then, the client could also report its metrics via Hadoop's metrics2 if
> desired or through another platform that utilizes the hbase-metrics-api.
> If left alone, client metrics will continue to be only barely visible through
> a client-side JMX server.
> The migration to the new metrics-api could be done by simply changing the
> Metrics data types from codahale types to hbase-metrics types without
> changing the metrics signatures of MetricsConnection unless completely
> necessary.
> The codahale MetricsRegistry would also have to be exchanged for a
> hbase-metrics MetricsRegistry.
> I found this to be a necessary change after attempting to implement my own
> Reporter to use within the MetricsConnection class.
> I was attempting to create a HadoopMetrics2Reporter that extends the codahale
> ScheduledReporter and reports the MetricsConnection metrics to Hadoop's
> metrics2 system.
> The already existing infrastructure in the hbase-metrics and
> hbase-metrics-api projects could be easily leveraged for a cleaner solution.
> If completed successfully, users could instead access their client-side
> metrics through the hbase-metrics-api.
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