Request Types in Nexus Core

Nexus Core supports nine request types covering CRUD, atomic increments, leaderboard queries, broadcasting, and cache preloading over Redis pub/sub.

Every packet sent to Nexus Core includes a type field that identifies the operation to perform. Nexus Core supports nine request types, each with a defined MongoDB operation and cache behavior. Understanding these types helps you choose the right one for each use case and reason about performance and consistency trade-offs.

All Request Types

Type	Description	MongoDB Operation	Cache Behavior
GET_DATA	Retrieves a document by its ID field	findOne()	Read-through
SET_DATA	Inserts or updates a document	replaceOne(upsert)	Write-through
REMOVE_DATA	Deletes a document by its ID	deleteOne()	Invalidate
INCREMENT_DATA	Atomically increments a numeric field	findOne() + in-memory mutation	Write-through
UPDATE_DATA	Partially updates fields in an existing document	updateOne()	Write-through
RANKING	Retrieves a global Top-N leaderboard (ASC or DESC)	Sorted query	Bypass
RANK_FINDER	Calculates a key’s position in the global ranking	Optimized query	Bypass
BROADCAST	Sends data to a target server via Redis pub/sub	None	Bypass
LOAD_CACHE	Preloads a document into memory by ID	findOne()	Warm

RANKING and RANK_FINDER bypass the cache entirely to guarantee a consistent global view of sorted data. BROADCAST has no MongoDB operation — it only routes a payload to another server’s Redis channel.

Common Request Types in Detail

GET_DATA

Retrieves a single document by its isId field value. Nexus Core checks the Redis L2 cache first. On a cache miss, it queries MongoDB and writes the result back to both cache layers before returning.

Example data payload:

{
  "uuid": "550e8400-e29b-41d4-a716-446655440000"
}

SET_DATA

Inserts a new document or replaces an existing one using replaceOne with upsert. The updated document is written through to both Redis and the L1 in-memory cache.

Example data payload:

{
  "uuid": "550e8400-e29b-41d4-a716-446655440000",
  "kills": 142,
  "deaths": 38,
  "balance": 2500.75,
  "isPremium": true
}

REMOVE_DATA

Deletes a document by its ID and invalidates the corresponding Redis and L1 cache entries.

Example data payload:

{
  "uuid": "550e8400-e29b-41d4-a716-446655440000"
}

INCREMENT_DATA

Atomically increments a numeric field (int, long, or double) without requiring a full SET_DATA round trip. Nexus Core reads the document, applies the mutation in memory, and writes the result back through the cache.

Example data payload:

{
  "uuid": "550e8400-e29b-41d4-a716-446655440000",
  "kills": 1
}

Related Topics

• Request Lifecycle — how each type flows through validation, routing, and cache
• Packet Structure — the full JSON format for incoming and outgoing packets
• Cache Strategy — read-through, write-through, and invalidation behaviors