[
https://issues.apache.org/jira/browse/HADOOP-8541?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13412049#comment-13412049
]
Aaron T. Myers commented on HADOOP-8541:
----------------------------------------
bq. The implementation matches the pseudocode and descriptions in the original
CKMS paper, so I'd like to leave the functions separate.
Makes sense. Sounds good.
bq. we wouldn't want our test failing due to leap seconds!
We certainly wouldn't. :)
The latest patch looks good to me. +1 pending Jenkins.
> Better high-percentile latency metrics
> --------------------------------------
>
> Key: HADOOP-8541
> URL: https://issues.apache.org/jira/browse/HADOOP-8541
> Project: Hadoop Common
> Issue Type: Improvement
> Components: metrics
> Affects Versions: 2.0.0-alpha
> Reporter: Andrew Wang
> Assignee: Andrew Wang
> Attachments: hadoop-8541-1.patch, hadoop-8541-2.patch,
> hadoop-8541-3.patch, hadoop-8541-4.patch, hadoop-8541-5.patch,
> hadoop-8541-6.patch
>
>
> Based on discussion in HBASE-6261 and with some HDFS devs, I'd like to make
> better high-percentile latency metrics a part of hadoop-common.
> I've already got a working implementation of [1], an efficient algorithm for
> estimating quantiles on a stream of values. It allows you to specify
> arbitrary quantiles to track (e.g. 50th, 75th, 90th, 95th, 99th), along with
> tight error bounds. This estimator can be snapshotted and reset periodically
> to get a feel for how these percentiles are changing over time.
> I propose creating a new MutableQuantiles class that does this. [1] isn't
> completely without overhead (~1MB memory for reasonably sized windows), which
> is why I hesitate to add it to the existing MutableStat class.
> [1] Cormode, Korn, Muthukrishnan, and Srivastava. "Effective Computation of
> Biased Quantiles over Data Streams" in ICDE 2005.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
