A budget in Azure: what it does and who gets the mail

You had IT set a budget of EUR 400 a month on your team’s scheduling tool. In part 3 you saw the three blocks the tool is made of, and on the bill they show up as three lines. EUR 260 compute, for the time the tool computes. EUR 90 storage, for what stays put. EUR 50 networking, for traffic going out. EUR 400 together.

That feels like a ceiling. But what does the budget actually do when November comes in more expensive, and who hears about it?

What a budget in Azure needs and does

A budget in Azure is an amount per month, quarter or year, with up to five thresholds on it. A threshold is a percentage of that amount at which you want a mail. Once every 24 hours the budget lays the costs next to the amount, and when a threshold is passed, a mail goes out to the recipients you gave it. Up to five fit on one budget.

Each threshold looks at either the actual costs, what has already been spent, or the forecast costs: where the month ends up if the pace stays the same. That choice mostly decides how early you hear about it.

What a budget does not do is step in. The tool keeps running, the costs keep building and nothing is shut off. The mail is a signal to a person, and that is all it is.

The signal also runs behind. The costs the budget checks are themselves 8 to 24 hours old, and on a pay-as-you-go subscription it can take longer. Add the check that happens once every 24 hours and the mail itself, and in the worst case you land around two days after the money was spent.

Which costs count: the tag

There is more on your Azure bill than this one tool, so a budget over everything says little about the scheduling tool. That is why you put a tag on everything that belongs to it. A tag is a label with a name and a value, such as application = planning. Have IT point the budget at that label, and it counts only what carries the label.

Three things about tags are worth knowing up front:

• The tag has to sit on each block itself, storage and networking included. A tag on the folder around them does not reach what is inside by itself.
• A tag only works going forward. Set it today and the budget counts from today, not last month’s costs.
• The value is case-sensitive. Planning and planning with a lowercase p are two different things in the cost reports, and so two separate lines.

November, the budgeting month

Up to and including the 15th the counter stands at EUR 200, exactly half a regular month. Then everyone on your team builds their budget in the tool, and from the 16th it computes twice as long each day. Only compute moves along, storage and networking stay at EUR 90 and EUR 50.

On the 25th the actual costs go over EUR 400. The mail about that arrives somewhere between the 25th and the 27th, and the whole time the tool keeps computing. November ends at EUR 530, of which EUR 390 is compute.

The budget did what a budget does: after a few days it reported that you were over the amount. Steering the month is up to whoever reads the mail.

The same November, on forecast costs

Now point the same threshold at the forecast costs and leave everything else alone. The mail goes out as soon as the projection for November crosses EUR 400, and that can be before the actual costs get there. The bill still ends at EUR 530 if nobody decides anything.

You gain time to decide, and that is all you gain. What happens with that time is up to the people reading the mail.

Who opens the mail

Who gets that mail in your organisation, and can that person decide that November is worth it? If you ask me, the mail belongs with the owner: the person or team that decides about the tool. That is rarely whoever created the budget. A mail sitting with IT about spending IT does not decide on stays there until someone forwards it.

One boundary to take with you: a budget on a tag counts only what carries that label, and only from the day it was put there.

Four questions for your own budget

Walk through it for your team’s tool. Is there an amount and a period on it? Does the threshold look at actual or at forecast costs? Does every block carry the tag, storage and networking included? And does whoever decides about the tool get the mail?

Part 5 closes the series and puts resources, permissions and costs side by side. Together they decide what you can build reliably, and that is why they are data strategy too.

Want to walk through this for your own environment? I’m happy to think it through with you, see trainerbjorn.nl.