interaction-store

Interaction Store

A high-performance ScyllaDB-based system for storing and querying user interaction data (clicks, orders, wishlist, etc.) with sub-10ms latency guarantees. Part of the BharatML Stack.

Features

• Last Y Days: Retrieve all interactions from last Y days (up to 168 days (~ 24 weeks) / 2,000 interactions)
• Weekly Time-Bucketed Storage: Data partitioned into weekly columns with ZSTD compression
• Vertical Sharding: Tables split into 8-week chunks for query isolation and efficient compaction

Architecture

┌──────────────────────────────────────────────────────────────────┐
│ Interaction Store │
├──────────────────────────────────────────────────────────────────┤
│ cmd/serving │ cmd/consumers │
│ (gRPC + HTTP API) │ (Kafka Consumer) │
├──────────────────────────────────────────────────────────────────┤
│ Handlers: Click | Order │
│ ├── Persist: Write interactions to storage │
│ └── Retrieve: Query interactions by time range │
├──────────────────────────────────────────────────────────────────┤
│ Data Layer │
│ ├── PSDB (Permanent Storage Data Block) with ZSTD compression │
│ └── ScyllaDB (RF=2, STCS Compaction) │
│ ┌──────────────┬───────────────┬───────────────┬──────────┐ │
│ │ week_1_to_8 │ week_9_to_16 │ week_17_to_24 │ metadata │ │
│ └──────────────┴───────────────┴───────────────┴──────────┘ │
└──────────────────────────────────────────────────────────────────┘

gRPC Service

serviceInteractionStoreTimeSeriesService {
rpcPersistClickData(PersistClickDataRequest) returns (PersistDataResponse) {};
rpcPersistOrderData(PersistOrderDataRequest) returns (PersistDataResponse) {};
rpcRetrieveClickInteractions(RetrieveDataRequest) returns (RetrieveClickDataResponse) {};
rpcRetrieveOrderInteractions(RetrieveDataRequest) returns (RetrieveOrderDataResponse) {};
rpcRetrieveInteractions(RetrieveInteractionsRequest) returns (RetrieveInteractionsResponse) {};
}