cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Christian Esken (JIRA)" <j...@apache.org>
Subject [jira] [Comment Edited] (CASSANDRA-13265) Expiration in OutboundTcpConnection can block the reader Thread
Date Thu, 13 Apr 2017 11:59:41 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-13265?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15967484#comment-15967484
] 

Christian Esken edited comment on CASSANDRA-13265 at 4/13/17 11:59 AM:
-----------------------------------------------------------------------

There were different reasons why the build failed, e.g. somehow Eclipse did not pick up the
build parameters for 2.2 after "ant generate-eclipse-files" and the build was done with Java
8 language level (lambdas). Looks like building and testing in Eclipse alone is not enough,
so I redid everything manually in the console and fixed the issues. As you recommended, I
have created branches that follow your naming  (cassandra-13625-3.0) with squashed commits.
The new branches are:

https://github.com/christian-esken/cassandra/commits/cassandra-13625-2.2
https://github.com/christian-esken/cassandra/commits/cassandra-13625-3.11
https://github.com/christian-esken/cassandra/commits/cassandra-13625-3.0
https://github.com/christian-esken/cassandra/commits/cassandra-13625-trunk

About CHANGES.TXT: I added changes in the "matching" release versions that were listed in
the individual branches. Please check, as the naming conventions within Cassandra are still
not clear to me (e.g. there exists a 3.11 branch, a 3.0.11 release and a 3.11.0 changelog
entry).


was (Author: cesken):
There were different reasons why the build failed, e.g. somehow Eclipse did not pick up the
build parameters for 2.2 after "ant generate-eclipse-files" and the build was done with Java
8 language level (lambdas). Looks like building and testing in Eclipse alone is not enough,
so I redid everything manually in the console and fixed the issues. As you recommended, I
have created branches that follow your naming  (cassandra-13625-3.0) with squashed commits.
The new branches are:

https://github.com/christian-esken/cassandra/commits/cassandra-13625-2.2
https://github.com/christian-esken/cassandra/commits/cassandra-13625-3.11
https://github.com/christian-esken/cassandra/commits/cassandra-13625-3.0
https://github.com/christian-esken/cassandra/commits/cassandra-13625-trunk

About CHANGES.TXT: I added changes to  all branches where in the appropriate versions. Please
check, as the naming conventions within Cassandra are still not clear to me(e.g. there exists
a 3.11 branch, a 3.0.11 release and a 3.11.0 changelog entry).

> Expiration in OutboundTcpConnection can block the reader Thread
> ---------------------------------------------------------------
>
>                 Key: CASSANDRA-13265
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13265
>             Project: Cassandra
>          Issue Type: Bug
>         Environment: Cassandra 3.0.9
> Java HotSpot(TM) 64-Bit Server VM version 25.112-b15 (Java version 1.8.0_112-b15)
> Linux 3.16
>            Reporter: Christian Esken
>            Assignee: Christian Esken
>             Fix For: 3.0.x
>
>         Attachments: cassandra.pb-cache4-dus.2017-02-17-19-36-26.chist.xz, cassandra.pb-cache4-dus.2017-02-17-19-36-26.td.xz
>
>
> I observed that sometimes a single node in a Cassandra cluster fails to communicate to
the other nodes. This can happen at any time, during peak load or low load. Restarting that
single node from the cluster fixes the issue.
> Before going in to details, I want to state that I have analyzed the situation and am
already developing a possible fix. Here is the analysis so far:
> - A Threaddump in this situation showed  324 Threads in the OutboundTcpConnection class
that want to lock the backlog queue for doing expiration.
> - A class histogram shows 262508 instances of OutboundTcpConnection$QueuedMessage.
> What is the effect of it? As soon as the Cassandra node has reached a certain amount
of queued messages, it starts thrashing itself to death. Each of the Thread fully locks the
Queue for reading and writing by calling iterator.next(), making the situation worse and worse.
> - Writing: Only after 262508 locking operation it can progress with actually writing
to the Queue.
> - Reading: Is also blocked, as 324 Threads try to do iterator.next(), and fully lock
the Queue
> This means: Writing blocks the Queue for reading, and readers might even be starved which
makes the situation even worse.
> -----
> The setup is:
>  - 3-node cluster
>  - replication factor 2
>  - Consistency LOCAL_ONE
>  - No remote DC's
>  - high write throughput (100000 INSERT statements per second and more during peak times).
>  



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Mime
View raw message