High CPU on Node app

Description:

Issue with members connecting to the server. Some members cannot connect (just reload) when login-in. Some members are disconnected even login for a long time. Checking by top command we see that node application hogs 100%+ CPU. Restarting the Rocket.Chat server seems to temporarily solve the problem. But after a day or 2 we notice a very same issue, which restarting temporarily fix the problem.

Steps to reproduce:

From our observation: doing search from private chats or group chats seems to peak the CPU.
Although it normalize for a few minutes. But this is not an issue from the previous version of Rocket.Chat via Snap Installation 72.3.

Actual behavior:

top command screenshot
node application is at 100%+ CPU

Server Setup Information:

• Version of Rocket.Chat Server: 0.74.2
• Operating System: Ubuntu 16.04.2 LTS
• Deployment Method: manual install
• Number of Running Instances: 1
• DB Replicaset Oplog: N/A
• NodeJS Version: v8.11.3
• MongoDB Version: db version v3.6.10

Additional context

Relevant logs:

Start by reproducing the reported CPU spike during private or group chat searches using the listed Rocket.Chat, Ubuntu, Node.js, and MongoDB setup, while collecting server logs and profiling data. Done means the cause of the sustained high CPU and connection failures is identified, addressed, and covered by a regression check.