[
https://issues.apache.org/jira/browse/HADOOP-7507?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13092139#comment-13092139
]
Luke Lu commented on HADOOP-7507:
---------------------------------
The patch only works around the jvm metrics problem. It doesn't really fix the
underlying issue of the Ganglia support: lack of tag/dimension/group support
(They are [working on tags
support|http://www.mail-archive.com/[email protected]/msg06822.html]).
Our current workaround is flatten the namespace, but in a inconsistent way, so
the it still won't work for QueueMetrics in CapacityScheduler.
I think for metrics1, the hardcoded workaround is probably OK (to minimize
disruption to old systems) but for metrics2, we could do something like this
for the groupName:
{code}
for (MetricsTag t : tags) {
if (t.value() != null) {
sb.append('.').append(t.value());
}
}
{code}
> jvm metrics all use the same namespace
> --------------------------------------
>
> Key: HADOOP-7507
> URL: https://issues.apache.org/jira/browse/HADOOP-7507
> Project: Hadoop Common
> Issue Type: Bug
> Components: metrics
> Affects Versions: 0.20.2
> Reporter: Jeff Bean
> Assignee: Alejandro Abdelnur
> Fix For: 0.23.0
>
> Attachments: HADOOP-7507-v2.patch, HADOOP-7507v1.patch,
> HADOOP-7507v3.patch, JvmMetrics.java, hadoop-metrics.properties,
> screenshot-1.jpg
>
>
> Ganglia jvm metrics don't make sense because it's not clear which java
> process the metrics refer to. In fact, all hadoop java processes running on a
> node report their jvm metrics to the same namespace.
> The metrics are exposed by the "jvm" context in JvmMetrics.java. This leads
> to confusing and nonsensical graphs in ganglia and maybe other monitoring
> tools.
> One way to fix this is to make sure the process name is reported in the jvm
> context, making it clear which process is associated with the context, and
> separating out the jvm metrics per process.
> This is marked as an "incompatible change" because the fix provided removes
> the JVM metrics and replaces it with process-specific metrics.
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
