hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Íñigo Goiri (JIRA) <j...@apache.org>
Subject [jira] [Commented] (HDFS-14084) Need for more stats in DFSClient
Date Thu, 29 Nov 2018 23:11:00 GMT

    [ https://issues.apache.org/jira/browse/HDFS-14084?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16704002#comment-16704002

Íñigo Goiri commented on HDFS-14084:

Internally, we have what we described in HDFS-12861.
This is a fair start for investigation on what's going on.
We also extended HTrace to collect resource utilization but that goes in a different direction.
In addition to throughput (as shown in HDFS-12861) what other metrics you are interested on?
DFSClient has plenty of metrics but they are not readily available and the easiest way to
get them is to dump them as a log; not the most convenient.

> Need for more stats in DFSClient
> --------------------------------
>                 Key: HDFS-14084
>                 URL: https://issues.apache.org/jira/browse/HDFS-14084
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>    Affects Versions: 3.0.0
>            Reporter: Pranay Singh
>            Assignee: Pranay Singh
>            Priority: Minor
>         Attachments: HDFS-14084.001.patch
> The usage of HDFS has changed from being used as a map-reduce filesystem, now it's becoming
more of like a general purpose filesystem. In most of the cases there are issues with the
Namenode so we have metrics to know the workload or stress on Namenode.
> However, there is a need to have more statistics collected for different operations/RPCs
in DFSClient to know which RPC operations are taking longer time or to know what is the frequency
of the operation.These statistics can be exposed to the users of DFS Client and they can periodically
log or do some sort of flow control if the response is slow. This will also help to isolate
HDFS issue in a mixed environment where on a node say we have Spark, HBase and Impala running
together. We can check the throughput of different operation across client and isolate the
problem caused because of noisy neighbor or network congestion or shared JVM.
> We have dealt with several problems from the field for which there is no conclusive evidence
as to what caused the problem. If we had metrics or stats in DFSClient we would be better
equipped to solve such complex problems.
> List of jiras for reference:
> -------------------------
>  HADOOP-15538 HADOOP-15530 ( client side deadlock)

This message was sent by Atlassian JIRA

To unsubscribe, e-mail: hdfs-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-help@hadoop.apache.org

View raw message