Node.js内存泄漏，尽管Heap + RSS大小不变

Question

According to my server monitoring, my memory usage is creeping up over time:

After ~4 weeks of uptime, it ends up causing problems / crashing (which makes sense, given that I'm on EC2 with m1.large instances => 8GB RAM, and RAM seems to be increasing at about 1.5 GB / week).

If I restart my node.js app, the memory usage resets. Yet... I'm keeping track of my memory usage via process.memoryUsage() , and even after ~1 week, I'm seeing

{"rss":"693 Mb","heapTotal":"120 Mb","heapUsed":"79 Mb"}

What am I missing? Clearly the leak is in node, yet the process seems to not be aware of it...

Answer 1

You can try node-memwatch module, which helps with leak detection and heap diffing in Node.

Heap diff would look similar to:

{
  "before": { "nodes": 11625, "size_bytes": 1869904, "size": "1.78 mb" },
  "after":  { "nodes": 21435, "size_bytes": 2119136, "size": "2.02 mb" },
  "change": { "size_bytes": 249232, "size": "243.39 kb", "freed_nodes": 197,
    "allocated_nodes": 10007,
    "details": [
      { "what": "String",
        "size_bytes": -2120,  "size": "-2.07 kb",  "+": 3,    "-": 62
      },
      { "what": "Array",
        "size_bytes": 66687,  "size": "65.13 kb",  "+": 4,    "-": 78
      },
      { "what": "LeakingClass",
        "size_bytes": 239952, "size": "234.33 kb", "+": 9998, "-": 0
      }
    ]
  }