Schema stitching when remote schema updates

[bialesdaniel]

/label discussion

If I am doing schema stitching from remote schemas and one of the schemas gets updated do I need to restart my service to get the new schemas? or should I be doing some sort of polling to figure out if the schemas have changed and or is there a better way to handle this pattern?

my code looks something like

    const link = new HttpLink({ uri: URI, fetch })
    const schema = await introspectSchema(link)
    const remoteSchema = makeRemoteExecutableSchema({
      schema,
      link
  })
  return usersSchema
    const server = new GraphQLServer({
      schema: remoteSchema
    })
    server.start({port: 3000})

[bialesdaniel]

Anyone have thoughts?

[bialesdaniel]

@krisread Yah I like the idea of a schema version. I don't think anything has to automatically sync or retry but if the response always included a version then the client could respond as they deem necessary. For example if there is no error but the schema version doesn't match, maybe an async retrieval of the new schema would be good, but in a case where there are errors and a different schema it would be good to sync the schemas and retry the request.

[bialesdaniel]

After talking with some more people about this I have changed my opinion on it. I think the point of Graphql is to be versionless. In an ideal world you would never make breaking changes to the schema, you would just deprecate things and monitor for when most people stop using them and then remove them.

AirBnb has a good talk about their graphql API tier where they briefly touch on how they do schema updates: https://youtu.be/tSoEAjvvtYI?t=21m6s

[eventless]

Any update on this, running into similar issue - The temporary work around is to bounce our gateway server with every downstream deployment. This is not ideal

[richardhomewood]

Would love to see something from Apollo to solve this - relying on deployments to re-introspect downstream schemas is not ideal.

Some other options we are looking at:

• a scheduled job to keep the downstream schemas in sync
• a "push" notification from downstream schemas that are updated
• if a request fails, re-introspect a downstream schema and try the request again

None of which feel like the complete solution.

[flippidippi]

Still looking for a better solution for this. When wrapping a remote schema that you do not control, it would be nice to have an easy way to update the schema when something changes.

[breuerfelix]

2019 and it is still a relevant topic here.
looking forward for any updates on this topic.

[fluggo]

I've started adding an extra HTTP header that gives the startup time of the downstream service. The upstream aggregator tracks the latest startup times and polls with HEAD occasionally, and if it sees a later startup time, it re-introspects and reconstructs the upstream schema. A tad ugly, but nice when it works.

[corentingiraud]

Any news about this ?
There is no better option than re-introspect remote schema on every request ?

[Gasperan]

Would love to see something from Apollo to solve this - relying on deployments to re-introspect downstream schemas is not ideal.

Some other options we are looking at:

• a scheduled job to keep the downstream schemas in sync
• a "push" notification from downstream schemas that are updated
• if a request fails, re-introspect a downstream schema and try the request again

None of which feel like the complete solution.

When you know that you have to re-instrospect the downstream schema how you update the schemas loaded into the server? are you restarting it? if you have some example of this, will be usefull to me

[codeandgraphics]

If you want to upgrade schema in runtime for Apollo Server, you can just do this:

      const schema = await createSchema()
      // Got schema derived data from private ApolloServer method
      // @ts-ignore
      const schemaDerivedData = await apolloServer.generateSchemaDerivedData(
        schema,
      )
      // Set new schema
      set(apolloServer, 'schema', schema)
      // Set new schema derived data
      set(apolloServer, 'schemaDerivedData', schemaDerivedData)

And all refresh stuff will work like a charm

[ad-das]

If you want to upgrade schema in runtime for Apollo Server, you can just do this:

      const schema = await createSchema()
      // Got schema derived data from private ApolloServer method
      // @ts-ignore
      const schemaDerivedData = await apolloServer.generateSchemaDerivedData(
        schema,
      )
      // Set new schema
      set(apolloServer, 'schema', schema)
      // Set new schema derived data
      set(apolloServer, 'schemaDerivedData', schemaDerivedData)

And all refresh stuff will work like a charm

what is the set() function you are calling here? Where does that get defined?

[natschoman]

what is the set() function you are calling here? Where does that get defined?

It's from lodash, looks something like this

import set from 'lodash/set';
...
const server = new ApolloServer(config);
setInterval(async () => {
  const newSchema = await createRemoteSchemas();
  const schemaDerivedData = await server.generateSchemaDerivedData(newSchema);
  set(server, 'schema', newSchema);
  set(server, 'schemaDerivedData', schemaDerivedData);
}, POLLING_INTERVAL_IN_MS);
...

[tvvignesh]

We are having a discussion about this here: #2022 just in case you guys want to pitch in.

[dotansimha]

Take a look at this: gmac/schema-stitching-handbook#3