How to Prevent Hangs on SocketInputStream.socketRead0 in Java?

What can I do to prevent hangs on SocketInputStream.socketRead0 in Java while performing multiple HTTP requests?

// Example Code Snippet for HttpClient Configuration
SocketConfig socketConfig = SocketConfig.custom()
            .setSoKeepAlive(false)
            .setSoLinger(1)
            .setSoReuseAddress(true)
            .setSoTimeout(5000)
            .setTcpNoDelay(true).build();

HttpClientBuilder builder = HttpClientBuilder.create();
builder.disableAutomaticRetries();
builder.disableContentCompression();
builder.disableCookieManagement();
builder.disableRedirectHandling();
builder.setConnectionReuseStrategy(new NoConnectionReuseStrategy());
builder.setDefaultSocketConfig(socketConfig);

RequestConfig config = RequestConfig.custom()
            .setCircularRedirectsAllowed(false)
            .setConnectionRequestTimeout(8000)
            .setConnectTimeout(4000)
            .setMaxRedirects(1)
            .setRedirectsEnabled(true)
            .setSocketTimeout(5000)
            .setStaleConnectionCheckEnabled(true).build();

Socket hangs on `SocketInputStream.socketRead0()` are common when performing a large number of HTTP requests due to thread blocks on socket read operations. To mitigate this issue, it's crucial to understand the underlying configurations and ensure proper timeout settings.

// Adding the timeout configuration in HttpClient
RequestConfig config = RequestConfig.custom()
            .setConnectionRequestTimeout(8000)
            .setConnectTimeout(4000)
            .setSocketTimeout(5000)
            .build();

HttpGet request = new HttpGet(url);
request.setConfig(config);

Causes

• Network instability leading to prolonged wait for a socket read operation.
• Server response delays on the remote end causing the socket to wait indefinitely.
• Misconfigurations in the HttpClient setup, especially concerning timeouts.

Solutions

• Implement adequate timeout settings for both connection and socket operations as configured in `RequestConfig`.
• Use a dedicated thread pool for executing HTTP requests to avoid blocking the main application thread.
• Consider employing an alternative library with better error handling and timeout capabilities, such as OkHttp.

Mistake: Not setting both connection and socket timeouts.

Solution: Always set appropriate connection timeouts to ensure that a blocked thread does not hang indefinitely.

Mistake: Ignoring the right configuration for the socket settings in the HttpClient.

Solution: Ensure proper adjustments to the `SocketConfig` settings to cater for various networking scenarios.