I’m using Bedrock/Claude to stream output to a mobile app using Sockets.
I’m aware that this error occurs when we use post_to_connection within $connect, which I am not doing.
It also is known to happen when the ConnectionID changes unexpectedly.
And I know the max execution time for a Lambda function is 29 seconds. Mine executes for no more than 5-8 seconds, even when it makes this error.

"errorType": "GoneException",
"errorMessage": "UnknownError",
"name": "GoneException",
"$fault": "client",
"$metadata": {
    "httpStatusCode": 410,
    "requestId": "4cbe31d8-1039-40bb-b840-bed29ca70991",
    "attempts": 1,
    "totalRetryDelay": 0
}

My code actually works, but I’m getting this error very randomly and inconsistently. I don’t know what is causing it. Most requests work, but sometimes the very same request will cause this error. I’m not seeing any disconnect notifications on my front-end when this happens.

I do implement a keep-alive heartbeat that sends an empty request to my API-Gateway (but has no routes that do anything to my Lambda function) – this is to keep my cost down, when all I need is the socket alive, not my lambda function constantly warm.

Here is my Lambda Code

export const handler = async (event:APIGatewayProxyWebsocketEventV2):Promise<any> => {

    if(event.requestContext){
        const {connectionId, routeKey} = event.requestContext
        var body
        try {
        body = (event.body)?JSON.parse(event.body):{}
        } catch (error){
            console.error(error)
            body = {}
        }

        switch(routeKey){
            case '$connect':
                return {statusCode:200}
                break;

            case '$disconnect':
                return {statusCode:200}
                break;

            case 'ask':
                if(!body.payload) { return}
                const _conversation:_Message[] = body.payload
                const conversation:Message[] = _conversation.map((x:_Message)=>({
                    role:x.role,
                    content: [ {text: x.content} ],
                }))

                const command = new ConverseStreamCommand({
                    modelId,
                    messages: conversation,
                    inferenceConfig: { maxTokens: 512, temperature: 0.5, topP: 0.9 },
                }); 

                const response = await client.send(command);

                if(response.stream){
                    for await (const item of response.stream) {
                        if (item.contentBlockDelta) {
                            if(item.contentBlockDelta.delta && item.contentBlockDelta.delta.text){
                                await gateClient.postToConnection({
                                    ConnectionId: connectionId,
                                    Data: item.contentBlockDelta.delta.text
                                })

                            }
                        }
                    }

                    await gateClient.postToConnection({
                        ConnectionId: connectionId,
                        Data: Buffer.from('//EOS//')
                    })
                }
                return {statusCode:200}
        }
    }
}

I have no idea how to even debug this problem. Any help is greatly appreciated.