Linux nodejs function with multiple eventhub output bindings not sending data

Short intro: HTTP Trigger which is calling the function, then take a message and put that via output binding to 4 other eventhubs

• Timestamp: 2021-02-17T09:53:41.423
• Function App version: 3
• Function App name: [company data, try to deliver everything else]
• Function name(s) (as appropriate): Functions.HttpTrigger1
• Host InstanceId ID: f00d3e73-aec3-4f1d-9931-fbd2e8c0e309
• Executing ‘Functions.HttpTrigger1’ ID: 2b28d94b-82d6-4ba0-8069-4d4d5d065c02
• Region: westeu [cannot see the function started id in the logs]

Repro steps

Provide the steps required to reproduce the problem:

• create four eventhubs
• create a function app in an appserviceplan
• create a http trigger function with four output bindings to the corresponding eventhubs
• call that function

Expected behavior

Would have expected the message to be delivered to all four eventhubs

Actual behavior

Nothing happens, just trigger no error no issue.

Known workarounds

none

BUT if you comment out three of the four output bindings then the left one ist working. You can do this for every output, so the connection strings are not the problem. AND the same can be reproduced with python…

Related information

Stack NodeJS NodeJs 12 LTS Authorization anonymous

Appsettings the Connectiong strings to the hubs

Source

module.exports = async function (context, req) {

    const name = (req.query.name || (req.body && req.body.name));
    const responseMessage = name
        ? "Hello, " + name + ". This HTTP triggered function executed successfully."
        : "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response.";

    let tempBufferDEV = [{'fruit':'Apple'}, {'fruit':name}];
    let tempBufferTEST = [{'fruit':'Apple'}, {'fruit':name}];
    let tempBufferSTAGE = [{'fruit':'Apple'}, {'fruit':name}];
    let tempBufferPROD = [{'fruit':'Apple'}, {'fruit':name}];

    // test
    context.bindings.outputEventHubIoTDataMessagesTest = tempBufferTEST;
    
    // dev
    context.bindings.outputEventHubIoTDataMessagesDev = tempBufferDEV;
    
    // stage
    context.bindings.outputEventHubIoTDataMessagesStage = tempBufferSTAGE;
    
    // prod
    context.bindings.outputEventHubIoTDataMessagesProd = tempBufferPROD;
    
    context.res = {
        // status: 200, /* Defaults to 200 */
        body: responseMessage
    };
}```

</details>

[anthonychu]

@alrod @AnatoliB Could you please evaluate this item for an upcoming sprint? Thanks

[anthonychu]

The issue is possibly here: https://github.com/Azure/azure-functions-eventhubs-extension/blob/51be2e6eccd2b01ab32ebdf80160a9449b718418/src/Microsoft.Azure.WebJobs.Extensions.EventHubs/Config/EventHubOptions.cs#L210-L221

Notice in @KaiWalter’s sample the Event Hubs names are the same, but connection strings are different. However, it appears the extension uses a cache that’s keyed only on the Event Hub name and not the connection string.