accumulo-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Eric Newton (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (ACCUMULO-3396) HDFS reads are hanging
Date Wed, 10 Dec 2014 04:14:12 GMT

    [ https://issues.apache.org/jira/browse/ACCUMULO-3396?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14240618#comment-14240618
] 

Eric Newton commented on ACCUMULO-3396:
---------------------------------------

I'll investigate. Do you have a JIRA or recommendation somewhere that explains this setting?

> HDFS reads are hanging
> ----------------------
>
>                 Key: ACCUMULO-3396
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-3396
>             Project: Accumulo
>          Issue Type: Bug
>          Components: tserver
>    Affects Versions: 1.6.0, 1.6.1
>         Environment: rhel6 linux 2.6.32-279 (x86_64)
> java 1.7.0_67-b01
> hadoop CDH5.1.2, HA (2) federated (2) NN configuration
> large production cluster
>            Reporter: Eric Newton
>            Assignee: Eric Newton
>            Priority: Blocker
>
> On large clusters we are seeing various forms of HDFS reads hanging:
> Queries that never return.
> Major compactions that hang.
> Accumulo 1.6.1 incorporates detectors that report hanging major compactions and a monitor
display that reports scans by age.
> Stack traces show readers in sun.nio.ch.EPollArrayWrapper.epollWait and in org.apache.hadoop.ipc.Client.Call(Client.java:1362).
> Netstat results for the tablet server shows many connections with a single byte waiting
on the Recv-Q of the process, and no bytes waiting on the Send-Q.
> strace of the jvm shows the typical jvm thread noise (futex calls)
> jstack shows lots of read-requests to the NN.
> long-running MajC's do complete, albeit slowly.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message