stanfordnlp/CoreNLP · error · IllegalStateException

Could not delete shutdown key file

Error message

Could not delete shutdown key file

What it means

On server startup StanfordCoreNLPServer writes a random shutdown key to a temp file and calls deleteOnExit(). If a file already exists at that path and File.delete() fails (e.g. locked or permission issue), an IllegalStateException is thrown and the server cannot start.

Solutions

1. Remove the stale shutdown key file from java.io.tmpdir (file name is printed in the log at server start)
2. Ensure the process user has write/delete permission on java.io.tmpdir
3. Set -Djava.io.tmpdir to a writable directory
4. Kill lingering StanfordCoreNLPServer processes holding the file, then restart

Example fix

// before
java -cp corenlp.jar edu.stanford.nlp.pipeline.StanfordCoreNLPServer  // fails on locked tmp file
// after
java -Djava.io.tmpdir=/var/tmp/corenlp -cp corenlp.jar edu.stanford.nlp.pipeline.StanfordCoreNLPServer

String tmp = System.getProperty("java.io.tmpdir");
File dir = new File(tmp);
if (!dir.canWrite()) throw new IllegalStateException("tmpdir not writable: " + tmp);
File f = new File(tmp, shutdownKeyFileName);
if (f.exists() && !f.delete()) throw new IllegalStateException("Stale key file locked: " + f);

try {
  new StanfordCoreNLPServer(port, runProp, sslProp, strict, quiet, defaultProps);
} catch (IllegalStateException e) {
  if (e.getMessage().contains("Could not delete shutdown key file")) {
    System.setProperty("java.io.tmpdir", "/var/tmp/corenlp");
    // restart server with clean tmpdir
  } else throw e;
}

When it happens

Trigger: Starting StanfordCoreNLPServer when java.io.tmpdir contains a stale shutdown-key file that cannot be deleted (read-only tmpdir, file held open by another process, Windows file locking).

Common situations: Multiple CoreNLP server instances running under the same user; leftover files after a crash; containers with read-only /tmp; Windows locks from a previous unclean shutdown.

Related errors

• Could not open temporary feature index file for writing.
• Cannot initialize logger!
• Could not create directory <tgtDir.getAbsolutePath()>, as a…
• Could not create directory <tgtDir.getAbsolutePath()>
• Could not open temporary feature index file for reading.

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/7606085362eee9d4. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/pipeline/StanfordCoreNLPServer.java:225

                k -> String.format("\t\t\t%s = %s", k, this.defaultProps.get(k))).collect(Collectors.joining("\n")));

    this.serverExecutor = Executors.newFixedThreadPool(ArgumentParser.threads);
    this.corenlpExecutor = Executors.newFixedThreadPool(ArgumentParser.threads);

    // Generate and write a shutdown key, get optional server_id from passed in properties
    // this way if multiple servers running can shut them all down with different ids
    String shutdownKeyFileName;
    if (props != null && props.getProperty("server_id") != null) {
      shutdownKeyFileName = "corenlp.shutdown." + props.getProperty("server_id");
    } else {
      shutdownKeyFileName = "corenlp.shutdown";
    }
    String tmpDir = System.getProperty("java.io.tmpdir");
    File tmpFile = new File(tmpDir + File.separator + shutdownKeyFileName);
    tmpFile.deleteOnExit();
    if (tmpFile.exists()) {
      if (!tmpFile.delete()) {
        throw new IllegalStateException("Could not delete shutdown key file");
      }
    }
    this.shutdownKey = new BigInteger(130, new Random()).toString(32);
    IOUtils.writeStringToFile(shutdownKey, tmpFile.getPath(), "utf-8");
    // set status port
    if (props != null && props.containsKey("status_port")) {
      this.statusPort = Integer.parseInt(props.getProperty("status_port"));
    } else if (props != null && props.containsKey("port")) {
      this.statusPort = Integer.parseInt(props.getProperty("port"));
    }
    // parse blockList
    if (blockList == null) {
      this.blockListSubnets = Collections.emptyList();
    } else {
      this.blockListSubnets = new ArrayList<>();
      for (String subnet : IOUtils.readLines(blockList)) {
        try {
          this.blockListSubnets.add(parseSubnet(subnet));

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