hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hairong Kuang (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HDFS-724) Pipeline close hangs if one of the datanode is not responsive.
Date Sun, 13 Dec 2009 19:10:18 GMT

    [ https://issues.apache.org/jira/browse/HDFS-724?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12789930#action_12789930

Hairong Kuang commented on HDFS-724:

Let me provide more information about this patch:
1. heart beat is an empty packet with a sequence number of -1;
2. At the client side, heart beat packets are not queued in any of the queues because there
is no need to resend a heartbeat if there is an error sending heartbeats.
2. At the datanode side, heartbeats are queued in the ack queue. A datanode treats a heartbeat
the same as a regular data packet. The ack of a heartbeat packet is the same as a regular
data packet as well. To distinguish a heartbeat from an end-of-block packet, receivePacket
returns -1 when receiving an end-of-block packet.

Dhruba, please feel free to reach me if you need more explanation. I need this patch to be
committed before I committing HDFS-101.

> Pipeline close hangs if one of the datanode is not responsive.
> --------------------------------------------------------------
>                 Key: HDFS-724
>                 URL: https://issues.apache.org/jira/browse/HDFS-724
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: data-node, hdfs client
>    Affects Versions: 0.21.0
>            Reporter: Tsz Wo (Nicholas), SZE
>            Assignee: Hairong Kuang
>            Priority: Blocker
>             Fix For: 0.21.0
>         Attachments: h724_20091021.patch, pipelineHeartbeat.patch, pipelineHeartbeat1.patch,
> In the new pipeline design, pipeline close is implemented by sending an additional empty
packet.  If one of the datanode does not response to this empty packet, the pipeline hangs.
 It seems that there is no timeout.

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message