@SuppressWarnings({"squid:S2446"})
  protected void putBack(ISession session) {
    queue.push(session);
    synchronized (this) {
      // we do not need to notifyAll as any waited thread can continue to work after waked up.
      this.notify();
      // comment the following codes as putBack is too frequently called.
      //      if (logger.isTraceEnabled()) {
      //        logger.trace("put a session back and notify others..., queue.size = {}",
      // queue.size());
      //      }
    }
  }
Timeout of query can be set by users. A negative number means using the default configuration
of server. And value 0 will disable the function of query timeout.
iotdb-client/session/src/main/java/org/apache/iotdb/session/pool/SessionPool.java