DATA SYSTEMS / REDIS SEMANTICS LAB

Спроектируйте ключ. Удержите инвариант.

Пишите Redis-команды, запускайте их на детерминированном keyspace и проверяйте TTL, contention, cursor и стоимость операций.

● ENGINE READYRedis-compatible training enginedeterministic · in-memory · no network

CASE / HASH / TTL / STATE EXTERNALIZATION

Session state outside the pod

API pods must stay stateless. Create session s-2048 for tenant 42 and user 8421 as a hash, give the whole session a 30-minute lifetime, then read back both data and TTL.

FIXTURE: empty keyspace
TIMEBOX: 18 min
TARGET: Redis 7+

01 / CONTRACT

Какой инвариант нужен

Encode an opaque session key, field-addressable state and expiry as one explicit storage contract.

One hash per session

A hash updates individual fields without serializing the whole object. The opaque session id belongs in the key; credentials and raw bearer tokens do not belong in the value. Any API replica can now serve the request without sticky routing.

TTL is part of the write path

Redis keys are persistent by default. EXPIRE turns cleanup into a storage invariant; a sliding session refreshes that TTL on accepted activity. Persistence policy still decides how much session loss a restart may cause.

COMMAND SURFACEBOUNDED ENGINE

HSET · EXPIRE · HGETALL · TTL

02 / COMMANDS

redis-cli transcript

Инициализация command editor…

LOCAL SIMULATOR24 commands · 4 KB · isolated fixture

RESP / STATE / COST

Запустите command file. Simulator каждый раз начинает с канонического fixture и не меняет браузерное или серверное состояние проекта.