CACHE//STRATA — Distributed Cache Resilience Telemetry

FIG.01SCENARIOS

FIG.02WRITE POLICY

Sync to cache + DB. Strong consistency, but zero write-path protection — the DB absorbs every write.

FIG.2ACACHE CONFIGURATION

CACHE TIERONLINE

EVICTION POLICYskewed workload

CACHE CAPACITY5.0K / 6.0K keys

5.0K

SINGLE-FLIGHTanti-stampede

TTL JITTERdesync expiry

FIG.2BWORKLOAD

ARRIVAL RATErequests / sec

400/s

WRITE FRACTIONpurchases / total

25%

FIG.2CINVENTORY CONCURRENCY

Atomic DECR — the post-decrement value is returned in one indivisible step. Reject < 0. Oversell is impossible.

FIG.00ARCHITECTURE MAP — 3-TIER READ/WRITE TOPOLOGYCLIENT · CACHE · DATABASE

FIG.03DB QUEUEING MODEL

R = S/(1−ρ) · S=5ms · μ=8.0K QPS. Latency diverges as ρ→1; the cache holds the operating point left of the knee.

FIG.04LIVE TELEMETRY

CACHE HIT RATE

0.0%

DB UTILISATION ρ

LATENCY p50

0µs

LATENCY p99

0µs

DB THROUGHPUT

0QPS

ERROR RATE

0.00%

DIRTY ENTRIES

0unflushed

REPL LAG

20ms

POOL

0/30

EVICTIONS

0/s

FIG.05CACHE LEVERAGE

0req/s ABSORBED

The cache is shielding the DB from 0% of all traffic