Local caching

Stigg SDKs support local caching, which means that customer entitlements are stored in-memory to prevent network trips for subsequent entitlement access checks. It also makes our API redundant in the case it is unreachable for any reason (like a network outage), and the SDK can continue to evaluate access checks even when it's offline.

The local cache is invalidated by frequently polling for updates, or by listening to real-time updates delivered by a WebSocket streaming connection to our API (currently only available for the backend SDKs).

const client = await Stigg.initialize({  
  	// set the polling interval, default to 30 seconds  
  	entitlementPollingInterval: 5000,
});

Fallback strategy

In the case where the entitlement local data is missing (for example: when a new feature was added to the codebase, but has still not been added to a plan) or our API is unreachable (for example: during a drop of internet connectivity), a fallback strategy can be configured using the Stigg SDKs.

Global fallback configuration

A global fallback strategy can be defined during the SDK initialization, for example:

const stiggClient = Stigg.initialize({
  apiKey,
  entitlementsFallback: {
    'feature-number-of-seats': {
     	hasAccess: true,
    },
    'feature-templates': {
      hasAccess: true,
      usageLimit: 10
    }
  },
});

Entitlement-check fallback configuration

A fallback can also be defined during an entitlement check. When defined, entitlement-check fallbacks will override the global fallback configuration for the specific feature. For example:

const entitlement = stiggClient.getMeteredEntitlement({  
  featureId: 'feature-number-of-seats',
  customerId: 'customer-demo-id',  
  options: {  
    //if an error occurs, allow access with unlimited usage  
    fallback: {  
      hasAccess: true,  
      isUnlimited: true  
    }  
  }  
});

Metering usage when there's no internet connectivity

While the entitlements checks continue to work in offline mode, usage metering is postponed until the SDK will become online again. During that period, usage measurements are buffered in-memory and will not be counted as actual usage before they're sent and reach Stigg servers.

In case of a long-term outage, the measurements can be stored in a persistent cache (if provided) to avoid data loss if the process will crash while the SDK is offline.