Cache Service

This service lets your plugin interact with a cache. It is bound to your plugin too, so that you will only set and get values in your plugin's private namespace.

Configuration

The cache service can be configured using the backend.cache section in your app-config.yaml:

In-Memory (default)

backend:
  cache:
    store: memory

Memcache

backend:
  cache:
    store: memcache
    connection: user:pass@cache.example.com:11211

Redis

backend:
  cache:
    store: redis
    # Connection can be a simple URL string:
    connection: redis://localhost:6379
    # Or an object with additional options passed to the underlying client
    # (only supported for the Redis store):
    # connection:
    #   url: redis://localhost:6379
    #   pingInterval: 60000

    # Store-specific configuration (optional)
    redis:
      client:
        # Global namespace prefix for all cache keys
        namespace: 'my-app'
        # Separator used between namespace and plugin ID (default: ':')
        keyPrefixSeparator: ':'
        # Other Redis-specific options...
        clearBatchSize: 1000
        useUnlink: false

Valkey

backend:
  cache:
    store: valkey
    connection: redis://localhost:6379

    # Store-specific configuration (optional)
    valkey:
      # Global namespace prefix for all cache keys (including separator used between namespace and plugin ID)
      keyPrefix: 'my-app:'

Infinispan

backend:
  cache:
    store: infinispan

    # Store-specific configuration (optional)
    infinispan:
      servers:
        # IP address or hostname of the server (default: '127.0.0.1')
        - host: 127.0.0.1
          # Port number of the server (default: '11222')
          port: 11222
      # Name of the cache (default: 'cache')
      cacheName: cache
      mediaType: application/json
      authentication:
        # Whether authentication is enabled (default: 'false')
        enabled: true
        userName: yourusername
        password: yourpassword
        saslMechanism: PLAIN

A full list of configuration items is available here, including support for backup clusters.

Namespace Configuration

For Redis and Valkey stores, you can configure a global namespace that will be prefixed to all cache keys:

• Without namespace: Cache keys use only the plugin ID (e.g., catalog:some-key)
• With namespace: Cache keys use the format namespace:pluginId:key (e.g., my-app:catalog:some-key)

For Redis, keyPrefixSeparator controls what character is used between the namespace and plugin ID (defaults to :). For Valkey, you set the full keyPrefix including the separator.

Note: In-memory, Memcache and Infinispan stores do not support namespace configuration and will always use the plugin ID directly.

Using the service

The following example shows how to get a cache client in your example backend plugin and setting and getting values from the cache.

import {
  coreServices,
  createBackendPlugin,
} from '@backstage/backend-plugin-api';

createBackendPlugin({
  pluginId: 'example',
  register(env) {
    env.registerInit({
      deps: {
        cache: coreServices.cache,
      },
      async init({ cache }) {
        const { key, value } = { key: 'test:key', value: 'bob' };
        await cache.set(key, value, { ttl: 1000 });

        // .. some other stuff.

        await cache.get(key); // 'bob'
      },
    });
  },
});