Understanding Garbage Collection and hunting Memory Leaks in Node.js

⇒ Applying Memory Monitoring with Climem

→ Install Climem

• npm install climem -g

→ Executing

1. Nest.js: CLIMEM=8999 node -r climem dist/main.js
   1. Express: CLIMEM=8999 node -r climem index.js
2. npx climem 8999

→ AutoCannon // Trigger many requests in sequencie

We can simulate a large amount of requests to check our application performance. For this, we can use Autocannon command as example below:

npx autocannon -c 100 -d 30 -p 10 <http://localhost:3003/*endpoint*>

More commands can be found in the Autocannon documentation:

autocannon

⇒ Understanding Memory Leaks

• RSS → Total Size of Memory allocated for the whole process
• HEAP TOTAL → Total Size of Memory allocated inside the RSS for variables, instancies and others...
• HEAP USED → Actual Size of Memory being currently used (It's the most volatile!)