"Store reset while query was in flight(not completed in link chain)" when stopQuery is called right after resetStore. Race condition?

[nyanpasu]

Currently, queries are getting stuck in the QueryManager.fetchQueryPromises Map when stopQuery is called while that query is in flight.

Inside QueryManager.fetchQuery a subscription is added to the QueryInfo (QueryManager.query object) of the Observable representing the current request.

      this.setQuery(queryId, ({ subscriptions }) => ({
        subscriptions: subscriptions.concat([subscription]),
      }));

On the subscription, callbacks are set up to remove the queryId from QueryManager.fetchQueryPromises

        error: (error: ApolloError) => {
          this.removeFetchQueryPromise(requestId);
          // ...
        },
        complete: () => {
          this.removeFetchQueryPromise(requestId);
          // ...
        },

When stopQuery() is called before this query resolves, the promise will stay in that map because the subscription has been removed, therefore the callbacks to remove it will no long trigger.

  public stopQuery(queryId: string) {
    this.stopQueryInStore(queryId);
    this.removeQuery(queryId);
  }

  public removeQuery(queryId: string) {
    const { subscriptions } = this.getQuery(queryId);
    // teardown all links
    subscriptions.forEach(x => x.unsubscribe());
    this.queries.delete(queryId);
  }

Later on, this will cause problems when one tries to call resetStore()

  public resetStore(): Promise<ApolloQueryResult<any>[]> {
    return this.clearStore().then(() => {
      return this.reFetchObservableQueries();
    });
  }

  public clearStore(): Promise<void> {
    this.fetchQueryPromises.forEach(({ reject }) => {
      reject(
        new Error(
          'Store reset while query was in flight(not completed in link chain)',
        ),
      );
    });
    // ...
  }

Error: Network error: Store reset while query was in flight(not completed in link chain)
    at new ApolloError (bundle.umd.js:124)

Intended outcome:
I think queries should be removed from that Map after subscriptions get removed.

So as a solution, I might suggest that as part of the clean up for stopQuery, that the requestId should be removed from QueryManager.fetchQueryPromises. Perhaps there is a cancel method to evoke, or I should reject the promise with a new Error that the query has been cancelled.

Actual outcome:
Queries are staying in that Map.

How to reproduce the issue:
It's an edge case, but this is how I ran into this issue through react-apollo:

• Render a Query wrapped component.
• Call resetStore() via user interaction
• Immediately trigger a state change that results in that Query component being unmounted.

Versions

 apollo-client: 2.3.5
 react-apollo: 2.1.9

In hindsight I should have just written a PR instead.

[hwillson]

Thanks for the detailed issue report @nyanpasu. If you're interested in submitting a PR to help address this, that would be awesome!

[hwillson]

This issue is related to #3555, #3792 and #2919. We'll address them all in one shot.

[zzzzasd]

Hi, will this issue be resolved soon? Is there a workaround?

[abergenw]

I just ran into this same problem but from a slightly different angle. The promise returned by QueryManager.refetchObservableQueries() never resolves if QueryManager.removeQuery() has been called for a query before the result arrives.

[joelgetaction]

I'm also seeing this problem. Any fix yet? It definitely seems to be a race condition - if I add a timeout between logout and resetStore then this error goes away. It seems like as long as there's one more render between the logout and the resetStore then the error goes away. This is for an @client local query by the way.

[mohamedbrahimi]

I try this and it worked for me :
this.apollo.getClient().resetStore().then(() => {
// your code here
})

[nyanpasu]

Did you also follow the other steps here to reproduce the issue?

Render a Query wrapped component.
Call resetStore() via user interaction
Immediately trigger a state change that results in that Query component being unmounted.

[cheapsteak]

I wonder if someone could verify whether this is a good minimal reproduction of this bug?

https://codesandbox.io/s/rj3w4vm4xo

The significant bit:

  componentDidMount() {
    console.log('resetStore 1: start');
    this.props.client.resetStore()
      .then(() => console.log('resetStore 1: done'))
      .catch(e => {
        console.error('resetStore 1: failed', e);
      });

    setTimeout(() => {
      console.log('calling setState');
      // this removes the <Query/> from render and triggers its fetch to be cancelled
      this.setState({ shouldShowQuery: false }, () => {
        console.log('setState callback');
        console.log('resetStore 2: start');
        setTimeout(() => this.props.client
          .resetStore()
          .then(() => console.log('resetStore 2: done'))
          .catch(e => console.error('resetStore 2: failed', e))
          , 1000
        );
      });
    });
  }

Console output:

It doesn't seem to matter how long the timeout is, whenever the 2nd resetStore is called, the first resetStore's promise finally throws an exception

[cheapsteak]

@nyanpasu I couldn't quite reproduce the bug using your flow of

• Render a Query wrapped component.
• Call resetStore() via user interaction
• Immediately trigger a state change that results in that Query component being unmounted.

https://codesandbox.io/s/nnv997ply0

Output:

resetStore 1: start
calling setState
setState callback
resetStore 1: done

Would you have time to take a look and see what I'm missing?

[cheapsteak]

My bad, wasn't expecting "should fix ###" to close the issue

[jbaxleyiii]

Thanks for reporting this. There hasn't been any activity here in quite some time, so we'll close this issue for now. If this is still a problem (using a modern version of Apollo Client), please let us know. Thanks!

[qeternity]

Can confirm this is still an issue

[JanSmolko]

If somebody has still this issue... I resolved it with stop() before clearStore()

...
client.stop()
client.clearStore()
...

[azuxx]

If somebody has still this issue... I resolved it with stop() before clearStore()

...
client.stop()
client.clearStore()
...

I used this but it seems only worked in "current session of apollo". Which means that if I am doing the code like below, when I refresh the app I get the previous Apollo client state without the "clearing" thing. So User is still signed in even thought my auth headers have been cleared and signOut mutation completed successfully.

This is my AuthNavigator:

//other code...

//using lazy query for getting currentUser
const [
    getUserMe,
    {loading: loadingUserMe, error: errorUserMe, data: dataUserMe, client}
  ] = useLazyQuery(QUERY_USER_ME);
let _queryCompleted = false;

//other code...

//handler called after calling signOut mutation
signedOut: async () => {
      await AsyncStorage.multiRemove([
        'access-token',
        'client',
        'token-type',
        'expiry',
        'uid'
      ]).then(() => {
        if (client) {
          console.log('can clean Apollo cache');
          client.stop();
          client.clearStore().then((_) => {
            console.log('Apollo cache cleared');
            setAuthState((prev) => ({...prev, isSignout: true, userMe: null}));
            console.log(
              'AuthNavigator got signedOut, so cleared auth headers and cache and we show signIn screen'
            );
          });
        }
      });
    },
///...other code

useEffect(() => {
    const bootstrapAsync = async () => {
      console.log('AuthNavigator called userMe');
      getUserMe();
    };
    bootstrapAsync();
  }, []);

  if (dataUserMe && !_queryCompleted) {
    console.log('AuthNavigator got userMeData', dataUserMe);
    authState.userMe = dataUserMe.me;
    authState.isLoading = false;
    _queryCompleted = true;
  }

///...other code

Is there a way to kind "write" the clearing happened with client.clearStore()? 🙏🏻

[chris-guidry]

@azuxx to clear the store when signing out, try these two:

this.props.client.cache.reset();
this.props.resetStore();

Also, using await is enough for the async code so the .then is not needed. The proceeding code can just be in line.

[azuxx]

@azuxx to clear the store when signing out, try these two:

this.props.client.cache.reset();
this.props.resetStore();

Also, using await is enough for the async code so the .then is not needed. The proceeding code can just be in line.

@chris-guidry Thank you for your suggestion, I am using hooks and useLazyQuery so I tried like this with your suggestion but it does not work. Did the logout flow correctly, then I refreshed the app but there is still the logged user :(

signedOut: async () => {
      await AsyncStorage.multiRemove([
        'access-token',
        'client',
        'token-type',
        'expiry',
        'uid'
      ]);
      if (client) {
        console.log('can clean Apollo cache');
        await client.cache.reset();
        await client.resetStore();
      }
      setAuthState((prev) => ({...prev, isSignout: true, userMe: null}));
      console.log(
        'AuthNavigator got signedOut, so cleared auth headers and cache and we show signIn screen'
      );
    }

[azuxx]

@chris-guidry Fixed! It was also a server issue🤦🏻‍♂️

[benderillo]

I don't understand how this issue is closed while it is still there and happening.
And in my case neither client.cache.reset(); nor client.stop() helps.