By asking questions in a structured way (following this) it will be much easier to help you.

        And there's a high chance that you will find the solution along the way and you won't even have to submit it and wait for an answer. 😎

        final CountDownLatch endLatch = new CountDownLatch(threadCount);

        ExecutorService executor = Executors.newFixedThreadPool(threadCount);

        for (int i = 0; i < threadCount; i++) {
            executor.submit(new Runnable() {
                @Override
                public void run() {
                    try {
                        startLatch.await();
                        for (int j = 0; j < operationsPerThread; j++) {

errors.app.db.already.updated = Potrebbe essere stato aggiornato da un altro processo. Riprova l'operazione.
errors.app.db.already.exists = I dati esistono già. Riprova l'operazione.
errors.app.double.submit.request = Questa richiesta potrebbe essere già stata elaborata. Riprova l'operazione.
# _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
# you can define your messages here:
# e.g.

        CountDownLatch latch = new CountDownLatch(sessionCount);

        for (int i = 0; i < sessionCount; i++) {
            final int sessionIndex = i;
            executor.submit(() -> {
                try {
                    String sessionId = "concurrent-session-" + sessionIndex;
                    byte[] salt = preauthService.generatePreauthSalt();

      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent

      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent

of the Work and any modifications or additions to that Work or Derivative Works
thereof, that is intentionally submitted to Licensor for inclusion in the Work
by the copyright owner or by an individual or Legal Entity authorized to submit
on behalf of the copyright owner. For the purposes of this definition,
"submitted" means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to

      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent

      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent

    for (int i = 0; i < nTasks; i++) {
      String s = "a" + i;
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError =
          threadPool.submit(
              new Runnable() {
                @Override
                public void run() {
                  cache.getUnchecked(s);
                  computedCount.incrementAndGet();