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	1384938925	1320M,799K
load			none	0	0K	4527516269	4G,221M,794K
query			none	497791769	474M,748K	2552702265	2G,386M,457K
global			none	809614466	772M,111K	5185940339	4G,849M,714K
tc/jemalloc cache			none	721866512	688M,435K	-1	-1K
sum of all trackers			none	2029272747	1935M,271K	-1	-1K
process resident memory			none	7537836032	7G,20M,656K	13403009024	12G,494M,108K
process virtual memory			none	64406933504	59G,1007M,244K	64818180096	60G,375M,444K