Pull extremely slow when no messages on queue

0
votes

I am using pubsub with Gmail for push notifications.

The pubsub subscription recieves messages as expected.

When I pull the messages however I have noticed that if there are no messages to pull the delay in getting a response is very slow.

If there is at least 1 message to pull then the response is timely

Has anybody else experienced this?

The only fix I can come up with is to leave a message on the queue.

if (credential.RequestAccessTokenAsync(CancellationToken.None).Result)
{
    var pubsubSerivce = new Google.Apis.Pubsub.v1beta2.PubsubService(
    new BaseClientService.Initializer()
    {
        HttpClientInitializer = credential,
        ApplicationName = "iLink",
    });

    PullRequest pr = new PullRequest();
    pr.MaxMessages = 100;
    PullResponse prs = pubsubSerivce.Projects.Subscriptions.Pull(pr, "projects/vivid-canyon-90023/subscriptions/iLink").Execute();

    AcknowledgeRequest ak = new AcknowledgeRequest();

    if (prs != null && prs.ReceivedMessages != null)
    {                    
        ak.AckIds = new List<string>();
        string messageText = "";
        foreach (ReceivedMessage rm in prs.ReceivedMessages)
        {
            ak.AckIds.Add(rm.AckId);
            messageText += " | " + rm.Message.Data;
        }
        pubsubSerivce.Projects.Subscriptions.Acknowledge(ak, "projects/vivid-canyon-90023/subscriptions/iLink").Execute();
        Master.setSuccessPrompt("Pulled Total Meesage count of: " + prs.ReceivedMessages.Count + " | Data | " + messageText);
    }
    else
    {
        Master.setSuccessPrompt("No Messages to pull");
    }
}
1
google-cloud-pubsub

1 Answers

2
votes

This is not slow, just hanging and waiting for any messages. Try using returnImmediately=true.