Module invalidation 

Cache invalidation via PostgreSQL LISTEN/NOTIFY

This module provides distributed cache invalidation using PostgreSQL’s LISTEN/NOTIFY feature. When one WarpDrive instance invalidates a cache entry, all other instances are notified via PostgreSQL and can clear their local caches.

Architecture

Instance A                    Instance B
┌────────┐                    ┌────────┐
│ DELETE │                    │        │
│  key   │                    │        │
└───┬────┘                    └───▲────┘
    │                             │
    │    ┌──────────────┐         │
    └───►│  PostgreSQL  │─────────┘
         │    NOTIFY    │
         │   "key=foo"  │
         └──────────────┘

Example

use warpdrive::cache::coordinator::CacheCoordinator;
use warpdrive::cache::invalidation::InvalidationListener;
use warpdrive::config::Config;

let config = Config::from_env()?;
let cache = CacheCoordinator::from_config(&config).await?;

// Start listener in background (if PostgreSQL configured)
if let Some(db_url) = &config.database_url {
    InvalidationListener::spawn(
        db_url.clone(),
        config.pg_channel_cache_invalidation.clone(),
        cache.clone(),
    );
}

Structs

InvalidationListener

Cache invalidation listener

InvalidationMessage

Cache invalidation message format