HTTPRoute rules limit

[dport]

I just learned (by hitting the limit) that a single HTTPRoute for the Gateway API in GKE only supports 16 rules. Is there any way to raise this limit? If not, is there any known limitation on the number of HTTPRoutes? If not, I suppose what I should do is switch to using many HTTPRoutes instead of one route with many rules. I can't find any documentation on limits related to HTTPRoute (e.g. here or here). I figure I'd get confirmation on the best approach before implementing anything.

[francislouie]

Hi @dport,

Welcome to Google Cloud Community!

Yes, this is a limitation for HTTPRoute(Gateway). According to @youngnick, the main reasons are the etcd size limit. For more details you can visit this thread. 

For the recommendation, consider different Gateways for different traffic types and use multiple HTTPRoutes to split rules. 

Refer to these documentations on how to deploy HTTPRoutes and Gateways:

• Deploying Gateway Resources
• About Gateway API
• About HTTPRoute

I hope the above information is helpful.

[dport]

Hi,

This makes sense, good to know where the rules limit comes from. My question is, is there a limit on the number of HTTPRoutes you can have for a single gateway?

Thanks,
Daniel

[francislouie · Accepted solution]

Hi @dport,

I deep dived into the Gateway API repositories and could not find any number of HTTPRoute that a single gateway can have. However, in this thread, you will find a post that summarizes the limitation of HTTPRoute.

 Here is the repository of Gateway API. 

[dport]

Alright thanks! In a support ticket Google said that for GCP specifically, there is a quota on the max number of HTTPRoutes you can have. I'm struggling to find said quota but just a heads up for anyone else who reads this. See the "HttpRoutes" API limit link here: https://cloud.google.com/service-mesh/quotas#service_routing_api_limits.

[dport]

Thanks for deep diving into this! Seems like the best option is to just try it and see what happens. Hopefully hundreds / thousands of HTTPRoutes won't be an issue.