What is the length limit for URLs on the Google HTTP/HTTPS Cloud Load Balancer aka HTTP/HTTPS Forwarding Rule? I have had reports of HTTP/1.1 413 Request Entity Too Large error responses from the load balancer:
Is there a way to adjust the length limit?
Is there a way to tell (from load balancer metrics or logs) how many requests are rejected due to the length limit? There seems to be no results in StackDriver logs:
Related question: Amazon AWS ELB length limit
Google Fronted process all request made to any Google product/service. GFE is the first communication layer that controls all requests that get in and out the entire google network regardless of the product.
The maximum payload allowed including the header is around 16K, as such, total combined header length should be less than maximum limit. The requests which are bigger than 16K doesn't reach your application and are not logged in Stackdriver logging.
From https://cloud.google.com/load-balancing/docs/quotas#https-lb-header-limits:
The combined size of the request URL and request header is limited to 16KB.
The other answer is incorrect about logging (now at least, not sure about 2017). Requests with excessively long URLs are logged in the HTTP Load Balancer logs. You can find them with this query:
resource.type="http_load_balancer"
httpRequest.status=413
