[
https://issues.apache.org/jira/browse/HDFS-16565?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17532755#comment-17532755
]
Xiaoqiao He commented on HDFS-16565:
------------------------------------
[~jianghuazhu] Thanks for your report. Is it possible that application open
streaming but not close it ever? Did you try to dig who occupy the port of
source side?
> DataNode holds a large number of CLOSE_WAIT connections that are not released
> -----------------------------------------------------------------------------
>
> Key: HDFS-16565
> URL: https://issues.apache.org/jira/browse/HDFS-16565
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: datanode
> Affects Versions: 3.3.0
> Environment: CentOS Linux release 7.5.1804 (Core)
> Reporter: JiangHua Zhu
> Priority: Major
> Attachments: screenshot-1.png
>
>
> There is a strange phenomenon here, DataNode holds a large number of
> connections in CLOSE_WAIT state and does not release.
> netstat -na | awk '/^tcp/ {++S[$NF]} END {for(a in S) print a, S[a]}'
> LISTEN 20
> CLOSE_WAIT 17707
> ESTABLISHED 1450
> TIME_WAIT 12
> It can be found that the connections with the CLOSE_WAIT state have reached
> 17k and are still growing. View these CLOSE_WAITs through the lsof command,
> and get the following phenomenon:
> lsof -i tcp | grep -E 'CLOSE_WAIT|COMMAND'
> !screenshot-1.png!
> It can be seen that the reason for this phenomenon is that Socket#close() is
> not called correctly, and DataNode interacts with other nodes as Client.
--
This message was sent by Atlassian Jira
(v8.20.7#820007)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
