[Misc] Usage Doc for Prefill-decoding Disaggregation

[Xinyi-ECNU]

No description provided.

[github-actions]

migration_size	8.00 MB	16.00 MB	24.00 MB	32.00 MB	40.00 MB	48.00 MB	56.00 MB	64.00 MB	72.00 MB	80.00 MB	88.00 MB	96.00 MB	104.00 MB	112.00 MB	120.00 MB	128.00 MB	136.00 MB	144.00 MB	152.00 MB	160.00 MB	168.00 MB	176.00 MB	184.00 MB	192.00 MB	200.00 MB	208.00 MB	216.00 MB	224.00 MB	248.00 MB	352.00 MB
rpc_speed(GB/s)	1.05	1.58	1.88	2.00	2.16	2.23	2.25	2.25	2.39	2.48	2.45	2.43	2.56	2.59	2.55	2.64	2.68	2.54	2.61	2.67	2.41	2.79	2.62	2.64	2.52	2.47	2.75	2.62	2.86	3.24

migration_size	8.00 MB	16.00 MB	24.00 MB	32.00 MB	40.00 MB	48.00 MB	56.00 MB	64.00 MB	72.00 MB	80.00 MB	88.00 MB	96.00 MB	104.00 MB	112.00 MB	120.00 MB	128.00 MB	144.00 MB	152.00 MB	160.00 MB	168.00 MB	176.00 MB	192.00 MB	240.00 MB	280.00 MB	320.00 MB
gloo_speed(GB/s)	1.03	1.67	2.01	2.33	2.45	2.75	2.82	2.87	3.20	3.17	3.28	2.99	3.27	3.36	3.59	3.09	2.80	2.44	2.99	3.48	3.25	2.33	2.47	3.52	3.68

[KuilongCui]

as there are some bugs for migraiton, the ci didn't pass.
I will fix it later.
Now, just re-run the failed test

[KuilongCui]

Missing a description of the failover mechanism.

[github-actions]

prefill	p25	p50	p75	p95	p99	mean
latency(ms)	13478.72	51380.54	113524.15	136427.30	150863.80	64445.81

decode	p25	p50	p75	p95	p99	mean
latency(ms)	51.51	55.28	64.16	91.39	232.25	61.59

[CLAassistant]

All committers have signed the CLA.

[github-actions]

prefill	p25	p50	p75	p95	p99	mean
latency(ms)	22331.82	69087.93	101327.92	132419.66	143763.24	63773.35

decode	p25	p50	p75	p95	p99	mean
latency(ms)	52.22	56.03	65.43	108.66	272.55	64.03

[github-actions]

prefill	p25	p50	p75	p95	p99	mean
latency(ms)	19010.35	51957.98	109831.90	146296.89	178691.99	61143.34

decode	p25	p50	p75	p95	p99	mean
latency(ms)	53.12	58.57	76.49	119.23	264.28	69.83

[github-actions]

prefill	p25	p50	p75	p95	p99	mean
latency(ms)	19210.32	63736.45	112487.70	145522.58	172127.51	65107.77

decode	p25	p50	p75	p95	p99	mean
latency(ms)	52.41	56.56	66.74	118.99	303.16	67.98

[KuilongCui]

LGTM ：）

[github-actions]

prefill	p25	p50	p75	p95	p99	mean
latency(ms)	18272.04	64507.25	106716.45	135297.28	146702.78	65166.56

decode	p25	p50	p75	p95	p99	mean
latency(ms)	51.56	56.41	67.26	128.60	338.44	66.81