What causes "Failed to close edge socket server socket on {}:{}" in apache/seatunnel?

Verify single ownership of the server socket — only one thread closes it.

Failed to close edge socket server socket on {}:{}

Error message

Failed to close edge socket server socket on {}:{}

What it means

Warned by closeServerSocketQuietly() when closing the server socket during the retry/open path throws an IOException. The method is intentionally 'quiet' — it logs and continues rather than propagating — typically while giving up on a partially opened socket between retries.

Source

Thrown at seatunnel-connectors-v2/connector-edge-socket/src/main/java/org/apache/seatunnel/connectors/seatunnel/edgesocket/source/EdgeSocketIngressServer.java:148

                }
            }
        }
    }

    private void closeServerSocket() throws IOException {
        ServerSocket current = serverSocket;
        serverSocket = null;
        if (current != null) {
            current.close();
        }
    }

    private void closeServerSocketQuietly() {
        try {
            closeServerSocket();
        } catch (IOException e) {
            log.warn(
                    "Failed to close edge socket server socket on {}:{}",
                    "0.0.0.0",
                    config.getPort(),
                    e);
        }
    }

    private void receiveLoop() {
        while (isReceiverActive()) {
            try {
                openServerSocketWithRetry();
                if (!isReceiverActive()) {
                    return;
                }
                serveOneCollector();
            } catch (SocketTimeoutException ignored) {
            } catch (Exception e) {
                if (shouldExitOnException(e)) {
                    return;

View on GitHub (pinned to cf67b549a7)

Solutions

Verify single ownership of the server socket — only one thread closes it.
Check file-descriptor limits in the deployment environment (ulimit / container limits).
Confirm the port is not contended by another process (address-already-in-use during the retry loop).
Treat as benign if it follows a bind failure, but fix double-close if it appears during normal shutdown.

Example fix

// before
// close called from both stop() and openServerSocketWithRetry retry path
// after
if (serverSocket != null && !serverSocket.isClosed()) { serverSocket.close(); }

Defensive patterns

Strategy: try-catch

Try / catch

try { server.start(); } catch (IOException e) { log.warn("server open failed; port state: {}", e.getMessage()); } // close failures after this are benign

Prevention

Close the server socket in exactly one place (a single owner/finally block)
Check isClosed() before closing
Raise fd limits in containers (ulimit -n) for high-churn sockets

When it happens

Trigger: closeServerSocket() throws IOException during closeServerSocketQuietly(), usually called from openServerSocketWithRetry() after a failed or superseded bind attempt.

Common situations: Socket already closed by the OS or another thread (double-close), port in a half-open state after bind failure, resource exhaustion in containers with low fd limits.

Related errors

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/c8a20aab19edfec5. Report an issue: GitHub.