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	0	0K
schema_change			none	0	0K	0	0K
compaction			none	0	0K	1151340649	1098M,4K
load			none	133485473	127M,308K	3484901816	3G,251M,472K
query			none	765599712	730M,135K	4830443168	4G,510M,685K
global			none	663657343	632M,934K	3869094304	3G,617M,876K
tc/jemalloc cache			none	1013265712	966M,333K	-1	-1K
sum of all trackers			none	2576008240	2G,408M,689K	-1	-1K
process resident memory			none	7847870464	7G,316M,320K	12643684352	11G,793M,980K
process virtual memory			none	61563138048	57G,343M,188K	61905137664	57G,669M,348K