calling setOptions on subscriber does not take effect

[dermasmid]

if changing flowControl settings after calling .on they dont not get into effect

const subscription = pubSubClient.subscription(subscriptionNameOrId);
const messageHandler = message => {

  message.ack();
};

subscription.on('message', messageHandler);

// does not have any effect on flow control
subscription.setOptions({
flowControl: {
          maxMessages: 1,
          allowExcessMessages: true,
 }
})

[swarmiakimmo]

I was able to confirm the bug by testing the client with a local script.

[feywind]

Looks like it's not passing it down to the streaming pull subscriber stream. I'll verify what we want this to do, behaviour-wise.

[theabhinavdas]

Have the same issue. maxMessages doesn't work for me when using streaming pulls. Any alternative till this is fixed or would we have to do unary pulls?

[theabhinavdas]

@feywind What's also quite peculiar is that when I use options with subscriptions, it seems to square the number of maxMessages specified. For me, if I set this to 1, it does in fact seem to pull only one message (as noticed in my handler). When I set maxMessages to 2, it seems to pull 4 messages. When I set maxMessages to 3, it seems to pull 9 messages!

const subscription = pubSubClient.subscription(subscriptionNameOrId, {
    flowControl: {
      maxMessages: 1
    }
});

[theabhinavdas]

@dermasmid from this other issue, it seems setting allowExcessMessages: false in your options fixes the issue like so:

const subscription = pubSubClient.subscription(subscriptionNameOrId, {
    flowControl: {
      maxMessages: 1,
      allowExcessMessages: false
    }
});

It may additionally have something to do with you instantly ack-ing in your messageHandler where you'd expect StreamingPull to pull the next message?