Ambari dashboard memory usage explanation for spark cluster

Question

I am using Ambari to monitor my spark cluster, and I'm a little confused by all the memory categories; Can somebody with expertise explain what these terms mean? Thanks in advance!

Here is a screen shot of the Ambari Memory Usage zoom out:

Basically what do swap, Share, Cache and Buffer memory usage stand for? (I think I understand Total well)

Answer 1

There is nothing specific to Spark or Ambari here. These are basic Linux / Unix memory management terms:

In short:

• Swap is a part of memory written to disk. See Wikipedia and What is swap memory?.
• Buffer and cache are used for caching filesystem data and file data. See What is the difference between buffer vs cache memory in Linux? and Overview of memory management
• Shared memory is a part of virtual memory used for shared libraries.