[SalesForce] “403::Unknown client” Error When Connecting to Streaming API Push Topic

I am trying to connect to a Push Topic via the Salesforce Streaming API using Python. My application completes the initial handshake correctly, but then fails on the following connect call, with the error: "403::Unknown client".

My messages work as follows:

Handshake Request

{
    "channel":"/meta/handshake",
    "id":"1",
    "supportedConnectionTypes":["long-polling"],
    "version":"1.0",
    "minimumVersion":"1.0"
}

Handshake Response

{
    "channel":"/meta/handshake",
    "clientId":"xxx",
    "version":"1.0",
    "successful":true,
    "minimumVersion":"1.0",
    "id":"1",
    "supportedConnectionTypes":["long-polling"]
}

It's completed the handshake fine. And then…

Connect Request

{
    "channel":"/meta/connect",
    "clientId":"xxx",
    "id":"2",            
    "connectionType":"long-polling"
}

Connect Response

{
    "channel":"/meta/connect",
    "clientId":"xxx",
    "advice":{
        "reconnect":"handshake",
        "interval":500
    },
    "error":"403::Unknown client",
    "successful":false,
    "id":"2"
}

I have seen this issue here:
https://success.salesforce.com/issues_view?id=a1p30000000T0F0AAK

And read through the documentation, including:
http://www.salesforce.com/developer/docs/api_streaming/Content/DebuggingStreamingAPIApplications.htm

After reading this however, I am no closer to determining what the actual fault or problem is, or how to remedy it.

I have tried a lot of different things and am at a loss at how to get it to work. I am using this Bayeux client library https://github.com/dkmadigan/python-bayeux-client, with some custom amendments to get the authentication working.

Any help would be greatly appreciated.

Best Answer

I solved this by ensuring that the cookies returned in the handshake response were included in all other requests.

Related Solutions

[SalesForce] Streaming API – Channel Getting Disconnected after certain interval

I guess the topic is kind of outdated but in case Himanshu still needs it; I had a similar issue with a java client and push topics, took a couple days to find out that the cometd is actually dropping the connection, it was 2 hours in my case (default), yours may be different. That detail is given in old pdfs but not in the new one. So in short; renew the connection before it times out, meaning; unsubscribe (to prevent duplication), disconnect, connect, handshake and subscribe again. Hope it helps. Cheers.

In addition to my original post, on the page below Salesforce says it "may" happen, with a quite similar sample message to your problem. And it all goes back to the same solution, start over. connect, handshake, subscribe...

http://www.salesforce.com/developer/docs/api_streaming/Content/DebuggingStreamingAPIApplications.htm

[SalesForce] How to solve inconsistent 403::Unknown Client error on subscribe when using lightning:empApi

The problem in helper method posted is that it uses the isEmpEnabled function incorrectly.

The isEmpEnabled function returns a promise not a boolean. If this is fixed so that isEmpEnabled is called correctly then waiting for a successful response and subscribing USUALLY does not result in a 403 error, but it still happens occasionally on the first load of the page.

As far as I can tell it is actually required to call isEmpEnabled prior to requesting the component subscribe to any channels. If the isEmpEnabled is not called any subscription call is likely to result in the 403::Unknown client error. (note that the official usage example does not include usage of isEmpEnabled)

The corrected code is below.

/**
 * Gets EMP API cmp ready for event subscriptions. After successful initialization subscribes to error notifications
 * and executes the given callback.
 *
 * If already initialized then just executes given callback.
 *
 * @param cmp
 * @param postInitializeCallback
 */
initializeEmpApi: function(cmp, postInitializeCallback) {
    console.log('initializing EMP API');
    if (this.empApiInitialized) {
        console.log('EMP API already initialized');
        postInitializeCallback(cmp);
    } else {
        // Get the empApi cmp
        var empApi = cmp.find('scannerEmpApi');

        var helperRef = this;
        empApi.isEmpEnabled().then(function(enabled) {
            if (!enabled) {
                alert('cmp must be hosted in the Salesforce One app in order to listen to platform events');
                return;
            }
            console.log('EMP API is enabled');
            empApi.setDebugFlag(true);

            var onErrorCallback = function(error) {
                console.error('EMP API message: ' + JSON.stringify(error));
            }.bind(this);
            empApi.onError(onErrorCallback);

            // Initialize the push topic that we'll subscribe to
            helperRef.createControllerRequest(cmp, 'initializePushTopic', {},
                function(jsonBody) {
                    console.log('push topics initialized');
                    helperRef.empApiInitialized = true;
                    cmp.set('v.pushTopicName', jsonBody.regularPushTopicName);
                    cmp.set('v.errorPushTopicName', jsonBody.errorPushTopicName);
                    // helperRef.subscribeToScanningErrors(cmp);
                    postInitializeCallback(cmp);
                }
            );
        });

    }
},

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