During the load tests we have found the issue that causes the application to freeze and after requires restart application. After a small load tests (100 requests amount, 1TPS) - CachingClientConnectionFactory can't get connection from pool than cause freeze application and this behavior you can see in the thread dump. Also this issue not as the handled and we not get exceptions.
Thread dump in attachment. Summary:
cat jstack | grep "CachingClientConnectionFactory.obtainConnection" -wc
206 Threads can not be released.