HttpClient 4 hangs silently on socketRead
I have an application that continuously probes a remote HTTP API using a keep-alive connection.
Rarely, but sometimes the application will run silently after work for a while.
The socket is still open, but the remote API is not returning any data.
Httpclient has socket timeouts and connection timeouts, but how do I handle the timeout where we are already connected, the socket is still open, but the server is not returning data?
netstat -np
for the process:
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 redactedlocalip:31136 redactedforeignip:80 ESTABLISHED 11145/java
My httpclient:
SocketConfig socketConfig = SocketConfig.copy(SocketConfig.DEFAULT).setSoTimeout(25000).build();
BasicHttpClientConnectionManager connectionManager = new BasicHttpClientConnectionManager();
connectionManager.setSocketConfig(socketConfig);
return HttpClients
.custom()
.setUserAgent(USER_AGENT)
.setConnectionManager(connectionManager)
.setRetryHandler(new DefaultHttpRequestRetryHandler())
.build();
Resetting the main thread:
"main" #11 prio=5 os_prio=0 tid=0x00007f6b802ce800 nid=0x2b9f runnable [0x00007f6b675ec000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:150)
at java.net.SocketInputStream.read(SocketInputStream.java:121)
at org.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:139)
at org.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:155)
at org.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:284)
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:140)
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:57)
at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:261)
at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:165)
at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:271)
at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107)
at redacted.app.code.executemyRequest(MyClass.java:117)
I am using the latest version from maven "org.apache.httpcomponents: httpclient: 4.5"
The problem was a poorly managed HTTP server that never responded to certain requests but continued to maintain a TCP connection and send / receive keep-alive packets.
Apache HTTPClient does not have a built-in timeout to resolve these scenarios, the solution is to manually call the HTTPRequest $ abort () method after the designated amount of timeout.
Of course, it needs to be called from another thread, since the calling thread will be blocked.