Why does a Azure Front Door Rule Set Rule has an Order instead of a Weight?

Question

Why does a Azure Front Door Rule Set Rule has an Order instead of a Weight?

philippe.savary 20

When I programatically create Rules, it shows me that:

The delivery rules order values cannot have duplicates. RestError: The delivery rules order values cannot have duplicates.

Why is that? If I have to update a Rule Set this is really hard on me to find an Order number that is not duplicated (additional requests on the API). Would it be not more beneficial to use a Weight instead so that several Rules can have the same weight like when a path hat the same "depth"?

1 answer

Your answer

Answer 1

Deepanshu katara 18,140 MVP Moderator

Hello, Welcome to MS Q&A

Azure Front Door does not allow duplicate order values for delivery rules because each rule must have a unique priority value to ensure that the rules are processed in the correct sequence. This uniqueness prevents conflicts in rule evaluation and ensures that the system can determine which rule to apply first when multiple rules are triggered.

References:

What is a rule set in Azure Front Door? (front-door-standard-premium)
What is a rule set in Azure Front Door? (front-door-classic)
To avoid duplicate order values when programmatically creating rules, you can implement a mechanism to dynamically assign unique order values. Here are some strategies:

Incremental Order Assignment: Start with an initial order value and increment it for each new rule.
Check Existing Rules: Retrieve the existing rules and their order values, then assign a new order value that is not already in use.
Use a Hashing Mechanism: Generate a unique hash based on rule properties and use it as the order value.

By ensuring that each rule has a unique order value, you can avoid the error and ensure that your rules are processed correctly.

Please let us know if any further questions

Kindly accept answer if it helps

Thanks

Deepanshu

Deepanshu katara 18,140 Reputation points MVP Moderator

2024-10-16T06:01:43.8533333+00:00

Following up to see if the provided answer was helpful. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.
philippe.savary 20 Reputation points

2024-10-22T09:58:00.9433333+00:00
Hi There

Thank you for your answer. I wasn't aware of it since my profile won't show that A comment has been made like so:

But anyway...

Of course I could figure out the Order ID by doing

listByRuleSet

in the SDK:
https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/cdn/arm-cdn/src/operationsInterfaces/rules.ts

My argument here is that yes, Order is a way to do it, but the reality is often, that rules are dfined by navigational depth of the route.
/homeold to /home
/aboutold to /about
I would consider as weight 1. The first rule that matches will apply
/aboutold/team to /about/team
I would consider as weight 2. The first rule that matches there will apply

This would save me going to fetch the Order ID one or several times during the update to find the next free Order ID which is relatively API intensive and therefore slow.

Also using a Hashing is impossible since the order is an integer and hashes are not. I use this mechanism on the Name of the rule and it works well...
ChaitanyaNaykodi-MSFT 27,661 Reputation points Microsoft Employee Moderator

2024-11-06T02:14:49.26+00:00

@philippe.savary

Thank you for getting back.

My argument here is that yes, Order is a way to do it, but the reality is often, that rules are dfined by navigational depth of the route.

Yes the use of Order in selecting the rule is by design although it will help if you share this feedback on our feedback portal here so the product group can prioritize. Thank you!

Please "Accept the answer" if the information helped you. This will help us and others in the community as well.

Share via

Why does a Azure Front Door Rule Set Rule has an Order instead of a Weight?

1 answer

Your answer