Configure Introspection

When running wunderctl up, WunderGraph automatically sets up a number of file watchers to automatically re-generate the configuration and re-start the WunderGraph Server when changes are made to the configuration.

This approach has two downsides. First, we can only detect changes to the file system. So, if you're changing the schema of your database, you'd have to manually re-start the process, which would be inconvenient.

Second, whenever you change one of the configuration files, e.g. you modify a GraphQL Operation, wunderctl would have to re-introspect all data sources. This works fine for a small number of data sources, but doesn't really scale.

That's why we've introduced introspection caching.

If a cache entry is found for a data source, it's always used instead of introspecting the data source again.

It's possible to clear the cache by running wunderctl up --clear-introspection-cache.

If you want to enable introspection polling, set a reasonable interval for the pollingIntervalSeconds value. For most data sources, an interval of 2-5 seconds should be fine. For remote data sources with large schemas, we recommend setting the interval to a higher value to not overload the remote server.

// wundergraph.config.ts
const spaceX = introspect.graphql({
  apiNamespace: 'spacex',
  url: 'https://api.spacex.land/graphql/',
  introspection: {
    pollingIntervalSeconds: 5,
  },
})

It's also possible to disable introspection caching. Set disableCache to true, and wunderctl up will ignore the cache for this data source.

// wundergraph.config.ts
const spaceX = introspect.graphql({
  apiNamespace: 'spacex',
  url: 'https://api.spacex.land/graphql/',
  introspection: {
    disableCache: true,
  },
})

Disabling the cache can result in reduced performance, because the data source is introspected every time a configuration file is changed.