[
https://issues.apache.org/jira/browse/CXF-7122?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15644288#comment-15644288
]
William Montaz commented on CXF-7122:
-------------------------------------
Freeman,
for little help in your investigations, I discovered that
DefaultClientExchangeHandler only uses ConnectTimeout and
ConnectioNRequestTimeout (that time to get the connection from the pool). The
SocketTimeout in the request seems to be handled indirectly via
org.apache.http.impl.nio.reactor.AbstractIOReactor (see line 491). While the
CONNECTION_TTL seems to be handled at CPool level (timeToLive field). It is
quite hard to put back everything together.
> Infinite loop due to AsyncHTTPConduit read timeout with exhausted connection
> pool
> ---------------------------------------------------------------------------------
>
> Key: CXF-7122
> URL: https://issues.apache.org/jira/browse/CXF-7122
> Project: CXF
> Issue Type: Bug
> Components: Transports
> Reporter: William Montaz
> Assignee: Freeman Fang
> Priority: Critical
> Fix For: 3.2.0, 3.1.9
>
> Attachments: AsyncHTTPConduitTest.java
>
>
> Using AsyncHTTPConduit, when the underlying connection pool gets exhausted,
> requests waiting for a connection will lead to an infinite loop if they reach
> receive timeout.
> The problem occured on all versions of CXF above 3.0.5 (we did not tested
> other ones).
> Let's imagine a backend that's broken and leads to timeout for all requests.
> When handling requests, the cxf worker thread will eventually go in wait
> state (AsyncHTTPConduit:618), with a timeout that matches the
> HTTPClientPolicy.setReceiveTimeout() value, waiting for the NIO stack to
> complete and call notifyAll via responseCallback (AsyncHTTPConduit:455).
> The timeout on the wait is the big problem :
> With our broken backend, the connection pool is exhausted waiting for other
> requests to timeout. When a new request is made by cxf against this backend,
> after timeout time this will happen :
> - on the one side the reactor threads will get a connection from the pool
> and try to write to the output stream. Waiting in the pool is not considered
> as receive timeout.
> - on the other side the cxf worker thread will wake up (because of the
> timedout wait), and shutdown SharedOutputBuffer and SharedInputBuffer
> (AsyncHTTPClient:624)
> - reactor threads will go to infinite loop because they will try to
> produceContent from a shutdown buffer (SharedOutputBuffer:120)
>
> From there, application recovery is compromised.
>
> To fix that, timeout should be handled only via the client callback
> (AsyncHTTPConduit:463).
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
