Suthahar Jegatheesan MSDEVBUILD / blog Multi-Stack Dev Build · by Suthahar
Search
Azure

You picked the topic. Then it filled up.

Five Service Bus traps that only show themselves six months later.

What you'll learn

  • How the $Default rule keeps matching everything you filtered
  • Why one idle subscription fills the topic and pages the publisher
  • The five settings that prevent all of it, none of them code
Azure 10 steps 32 seconds —views

Was this useful?

Share

Understand it one step at a time

The short runs these in order in about 32 seconds. Here they are written out — pick any step to jump the short straight to it.

1 Step 1 of 10

You picked a topic. Good.

Four teams needed the same order event, so you created one topic with four subscriptions. At the time, that was exactly the right call.

Frequently asked questions

Why did a filtered topic subscription still receive everything?
A new subscription is created with a $Default rule that matches all messages — adding your own filter rule without removing $Default leaves both rules active, so the filter has no effect until the default rule is explicitly deleted.
How does one unused subscription end up paging the message publisher?
An idle subscription still receives and holds every matching message; if nobody is reading it, it fills up and can trigger size or quota alerts against the whole topic — which surfaces as a problem for the publisher, not the team that owns the abandoned subscription.

Free app · no app store

These are built for a phone

Every short is drawn at full portrait height, the shape a phone already is. Installed, it opens full-bleed with no address bar across the top — and the whole library reads offline.

How it works

Read deeper on Azure

Twenty seconds gets the shape of an idea across. These go into how it behaves in production.

More shorts

Get new posts by email

New technical articles, Azure AI and GitHub Copilot updates, and upcoming events. No spam, unsubscribe anytime.

↑↓ navigate ↵ open