Memory usage by subsystem

*Notice:

1. MemTracker only counts the memory on part of the main execution path, which is usually less than the real process memory.

2. each `type` is the sum of a set of tracker values, `sum of all trackers` is the sum of all trackers of all types, .

3. `process resident memory` is the physical memory of the process, from /proc VmRSS VmHWM.

4. `process virtual memory` is the virtual memory of the process, from /proc VmSize VmPeak.

5.`/mem_tracker?type=` to view the memory details of each type, for example, `/mem_tracker?type=query` will list the memory of all queries; `/mem_tracker?type=global` will list the memory of all Cache, metadata and other global life cycles.

see documentation for details.

Type	Label	Parent Label	Limit	Current Consumption(Bytes)	Current Consumption(Normalize)	Peak Consumption(Bytes)	Peak Consumption(Normalize)
experimental			none	0	0K	0	0K
clone			none	0	0K	53248	52K
schema_change			none	0	0K	0	0K
compaction			none	0	0K	1270709507	1211M,863K
load			none	459774912	438M,486K	4527516269	4G,221M,794K
query			none	497791769	474M,748K	1945199849	1855M,89K
global			none	99380973	94M,795K	5185940339	4G,849M,714K
tc/jemalloc cache			none	1913136024	1824M,520K	-1	-1K
sum of all trackers			none	2970083678	2G,784M,504K	-1	-1K
process resident memory			none	7596171264	7G,76M,280K	11328315392	10G,563M,536K
process virtual memory			none	64308850688	59G,913M,716K	64736882688	60G,297M,924K