The server randomly freezes with large requests, what is the reason for this?

Question

Oracle

Good afternoon,
There is a server on which Apache Tomcat 8.5 is installed (on which the service is directly installed), basically it receives requests from other servers to its own database, with a large influx of requests to the server, it freezes and freezes so that it is impossible to connect or somehow interact with it, that is, the system freezes (Except for IPMI).
By observation, while the system is running, I want to say that two services clog the RAM, namely TNG3LIVE.exe (commons daemon service runner) and oracle.exe (oracle rdbms kernel executable). Added RAM from 16 to 32GB, the problem remained, it hangs mostly every other day or 2 stably. I can not figure out the problem because the system freezes. The logs don't do much..