Launching EC2 instance failed in Auto Scaling Group


I have an autoscaling group, recently change to attribute based selection, and now have many errors:

Launching a new EC2 instance. Status Reason: Internal error. Launching EC2 instance failed.

during attempts scale-outs. I can't find any more detail as to what the error is.

asked 2 days ago7 views
1 Answer

I just found this in the CreateFleet event in Cloudtrail; I guess it could be the answer:

    "responseElements": {
        "CreateFleetResponse": {
            "fleetInstanceSet": "",
            "xmlns": "",
            "requestId": "7f5a500b-xxxxx",
            "fleetId": "fleet-f33db92e-xxxxxx",
            "errorSet": {
                "item": {
                    "errorCode": "UnfulfillableCapacity"

Update: seems like including some availability zones in the networking config for the ASG causes this problem. In my case, the CreateFleet request was attempting to create in us-east-1e - once I took that out of the network config, the following CreateFleet requests succeeded. I was under the impression that ASG/Spot took care of this case, but doesn't seem that way.

answered 2 days ago

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