I have a lambda that’s invoked dozens or hundreds of times per day, sometimes in quick succession, without issue for months. Today, for the first time, an invocation received a 200 response, and yet the lambda was not in fact executed. (I’m able to tell that the lambda wasn’t executed because all logs from that particular invocation, and only that invocation, are missing, and because the effect the invocation would have had did not occur.)
Here’s the response from the problematic invocation where the lambda did not get executed.
"status": 200,
"headers": [
{
"value": "public, max-age=0, must-revalidate",
"name": "cache-control"
},
{
"value": "text/plain; charset=utf-8",
"name": "content-type"
},
{
"value": "Fri, 13 Aug 2021 15:30:40 GMT",
"name": "date"
},
{
"value": "0",
"name": "age"
},
{
"value": "0",
"name": "content-length"
},
{
"value": "True",
"name": "x-bb-proxy"
},
{
"value": "v2",
"name": "x-bb-proxy-version"
},
{
"value": "Netlify",
"name": "server"
},
{
"value": "01FD025ZYMNQAS8343RGRN8GJ7",
"name": "x-nf-request-id"
}
]
By contrast, here’s the response from an invocation at nearly the same time where the lambda did execute normally.
"status": 200,
"headers": [
{
"value": "no-cache",
"name": "cache-control"
},
{
"value": "application/json",
"name": "content-type"
},
{
"value": "Netlify",
"name": "server"
},
{
"value": "01FD025ZYMS7H60H1HB8PV6PKV",
"name": "x-nf-request-id"
},
{
"value": "1",
"name": "age"
},
{
"value": "Fri, 13 Aug 2021 15:30:41 GMT",
"name": "date"
},
{
"value": "0",
"name": "content-length"
}
]
As you can see, the problematic invocation has headers that don’t appear in normal invocations, namely x-bb-proxy and x-bb-proxy-version. The content-type is also different.
I’ve found no meaningful information on what the x-bb-* headers represent, just a handful of miscellaneous references in other support tickets without going into detail on these headers.
Regardless, evidently it’s possible to invoke a Netlify function and get a 200 response without the function in fact being executed. That’s quite concerning. What could be causing it?