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)
overview	other		none	0	0K	0	0K
overview	schema_change		none	0	0K	0	0K
overview	compaction		none	0	0K	0	0K
overview	load		none	0	0K	0	0K
overview	query		none	0	0K	0	0K
overview	global		none	0	0K	0	0K
overview	tc/jemalloc_cache		none	156622224	149M,375K	-1	-1K
overview	tc/jemalloc_metadata		none	100058592	95M,433K	-1	-1K
overview	sum of all trackers		none	256680816	244M,808K	-1	-1K
overview	process resident memory		none	734957568	700M,932K	5112893440	4G,780M,36K
overview	reserve_memory		none	0	0K	-1	-1K
overview	process virtual memory		none	38445699072	35G,824M,692K	38450937856	35G,829M,688K