[HTTPCLIENT-1610] Stale connections in pool cause NoHttpResponseException

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 4.4 Final
• Fix Version/s: 4.4.1
• Assignee: Unassigned
• Reporter: Oliver Henlich
• Created: 11/Feb/15 02:23
• Updated: 21/Nov/19 09:22
• Resolved: 11/Feb/15 08:49

Description

Hi,

A few days ago we upgraded from httpclient 4.3.6 to 4.4.

Our application sends out webservice requests to various other servers hosted at our customers sites.
We noticed that a lot of these requests were failing with the following NoHttpResponseException exception. Unfortunately these exceptions seemed to be occurring intermittently.

On further experimentation we were able to reproduce it more reliably by waiting 1 minute between sending requests to the same url. This leads us to believe that this is potential issue with the connection pooling/re-use when the remote servers close/kill the connection.

We tried but failed to create a reproducible test case to attach to this request.

Notes:
1. CPool which is used by the default PoolingHttpClientConnectionManager does not override/implement validate(). Is this correct?
2. We noticed that since 4.4 the StaleConnectionCheck has been disabled by default (ClientConfiguration.java) as part of https://issues.apache.org/jira/browse/HTTPCLIENT-1493.

Questions:
1. Is something obvious we've missed in the configuration (shown below)? How do we avoid stale connections resulting in NoHttpResponseExceptions.
2. Would it make sense to switch to the BasicHttpClientConnectionManager to avoid these issues. Especially since our usage of httpclient does not seem to require connections to be re-used in this manner.

Cheers
Oliver

Configuration:

    public CloseableHttpClient buildRegularClient() {
        SSLContext sslContext = createSSLContext();

        RequestConfig globalConfig = RequestConfig.custom()
                .setCookieSpec(CookieSpecs.IGNORE_COOKIES) // By default we always want to ignore cookies
                .setSocketTimeout(getReadTimeout()) 
                .setConnectTimeout(getConnectTimeout()) 
                .build();

        HttpClientBuilder httpClientBuilder = HttpClients.custom()
                .setDefaultRequestConfig(globalConfig)
                .setMaxConnTotal(MAX_CONNECTIONS)
                .setMaxConnPerRoute(MAX_CONNECTIONS_PER_ROUTE);

        httpClientBuilder.addInterceptorFirst(new RemoveSoapHeadersInterceptor());
        httpClientBuilder.setSslcontext(sslContext);
        httpClientBuilder.setHostnameVerifier(getHostnameVerifier());

        return httpClientBuilder.build();
    }

Exception:

Caused by: org.apache.http.NoHttpResponseException: server.name.com:8080 failed to respond
        at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:143)
        at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:57)
        at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:260)
        at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:161)
        at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:153)
        at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:271)
        at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:123)
        at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:254)
        at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:195)
        at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:86)
        at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:108)
        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:106)
        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:57)

Issue Links

• duplicates: HTTPCLIENT-1609 Implementation of validate() Required In CPool