apache/seatunnel · error · IOException

SftpException wrapped (pwd failed while deleting)

Error message

SftpException wrapped (pwd failed while deleting)

What it means

SFTPFileSystem.delete() first resolves the current remote working directory via channel.pwd(); if the SFTP server rejects that call the SftpException is wrapped in an IOException with no added context. It means the 'pwd' step failed while attempting a delete, typically because the underlying SSH/SFTP channel is dead, not authenticated, or the server errored.

Source

Thrown at seatunnel-connectors-v2/connector-file/connector-file-sftp/src/main/java/org/apache/seatunnel/connectors/seatunnel/file/sftp/system/SFTPFileSystem.java:359

            return !getFileStatus(channel, file).isDirectory();
        } catch (FileNotFoundException e) {
            return false; // file does not exist
        } catch (IOException ioe) {
            throw new IOException(E_FILE_CHECK_FAILED, ioe);
        }
    }

    /**
     * Convenience method, so that we don't open a new connection when using this method from within
     * another method. Otherwise every API invocation incurs the overhead of opening/closing a TCP
     * connection.
     */
    private boolean delete(ChannelSftp channel, Path file, boolean recursive) throws IOException {
        Path workDir;
        try {
            workDir = new Path(channel.pwd());
        } catch (SftpException e) {
            throw new IOException(e);
        }
        Path absolute = makeAbsolute(workDir, file);
        String pathName = absolute.toUri().getPath();
        FileStatus fileStat = null;
        try {
            fileStat = getFileStatus(channel, absolute);
        } catch (FileNotFoundException e) {
            // file not found, no need to delete, return true
            return false;
        }
        if (!fileStat.isDirectory()) {
            boolean status = true;
            try {
                channel.rm(pathName);
            } catch (SftpException e) {
                status = false;
            }
            return status;

View on GitHub (pinned to cf67b549a7)

Solutions

  1. Check SFTP server connectivity and that the session/channel is still authenticated before the delete
  2. Reconnect (connect() / return channel to pool and re-acquire) and retry the delete
  3. Increase SSH keep-alive / ServerAliveInterval settings on the client to prevent idle disconnects
  4. Inspect the wrapped SftpException's id (e.g. SSH_FX_FAILURE vs SSH_FX_CONNECTION_LOST) to distinguish server error from dropped connection

Example fix

// before
boolean ok = fs.delete(new Path("/tmp/data/file.txt"), false);
// after
try {
    boolean ok = fs.delete(new Path("/tmp/data/file.txt"), false);
} catch (IOException e) {
    if (e.getCause() instanceof SftpException) {
        // reconnect / retry delete
    }
    throw e;
}
Defensive patterns

Strategy: try-catch

Validate before calling

boolean healthy = false;
try {
    fs.getFileStatus(new Path("."));
    healthy = true;
} catch (IOException e) {
    healthy = false;
}

Try / catch

try {
    fs.delete(path, recursive);
} catch (IOException e) {
    if (e.getCause() instanceof SftpException) { /* reconnect + retry */ }
    throw e;
}

Prevention

When it happens

Trigger: Calling delete(path), delete(path, recursive) or a create() that deletes an existing file for overwrite, when channel.pwd() throws (session closed by server, connection dropped, auth expired, or server-side failure on the pwd request).

Common situations: SFTP session idle timeout between connect and delete; network interruption mid-job; server closes channel after MAX_SESSIONS limit; using a channel returned to the pool after failure; firewall dropping long-lived SSH connections.

Understand the failure class

Background: ECONNREFUSED and "connection refused" / "could not connect to server" errors: what they mean and how to fix them — this error's family across 44 libraries.

Related errors

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/0f82750922cb475a. Report an issue: GitHub.