private void init() {
      for (int i = 0; i < perfConfig.perfNioServerConcurrency; i++) {
        slots.add(true);
      }
      logger.info("Setup to maintain concurrency of {}", perfConfig.perfNioServerConcurrency);
    }
Initializes load creation by adding slots based on concurrency required.
ambry-tools/src/main/java/com/github/ambry/tools/perf/rest/PerfNioServer.java