[ 
https://issues.apache.org/jira/browse/HADOOP-2910?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12579952#action_12579952
 ] 

Hairong Kuang commented on HADOOP-2910:
---------------------------------------

Ok, to avoid busy waiting, the listener checks if the call queue is full or not 
before it calls select. It waits if the queue is full. How does this sound?

I think it is ok to accept new connections when the queue is full. Otherwise it 
is going to fail the applications. Our goal is to slow down clients not to fail 
clients.

> Throttle IPC Client/Server during bursts of requests or server slowdown
> -----------------------------------------------------------------------
>
>                 Key: HADOOP-2910
>                 URL: https://issues.apache.org/jira/browse/HADOOP-2910
>             Project: Hadoop Core
>          Issue Type: Improvement
>          Components: ipc
>    Affects Versions: 0.16.0
>            Reporter: Hairong Kuang
>            Assignee: Hairong Kuang
>             Fix For: 0.17.0
>
>         Attachments: callQueue.patch
>
>
> I propose the following to avoid an IPC server being swarmed by too many 
> requests and connections
> 1. Limit call queue length or limit the amount of memory used in the call 
> queue. This can be done by including the size of a request in the header and 
> storing unmarshaled requests in the call queue. 
> 2. If the call queue is full or queue buffer is full, stop reading requests 
> from sockets. So requests stay at the server's system buffer or at the client 
> side and thus eventually throttle the client. 
> 3. Limit the total number of connections. Do not accept new connections if 
> the connection limit is exceeded. (Note: this solution is unfair to new 
> connections.) 
> 4. If receive out of memory exception, close the current connection. 

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

Reply via email to