Autopilot for Cosmos db – The Cost of Convenience

In the October 2019 update of Azure, Microsoft added ‘Autopilot’ that automatically controls the throughput of a Cosmos d/b. This is handy for unpredictable workloads.. like irregular imports, when you’ll hit the 400 RU maximum and have a Data Factory Pipeline cut out part way.

This can’t be retroactively set on existing Cosmos db containers.. only new ones.

We compared the cost to a d/b with a manual setting of 400 RUs and ran them for a couple of days with no usage.

This it how it looked in Cost Analysis:

Throughput
Daily Cost
Yearly Cost
400 RUs $0.75 $273
600 RUs $1.15 $419
Autopilot 4000 RU max $1.13 $412

As you can see, the standing charge is more expensive for Autopilot… $138/yr more expensive than 400 RUs. But equivalent to running at 600 RUs.

If you have a 400 RU container with predictable high-throughput bursts you can run a script to temporarily increase the RUs, then set them back when you’re done.. that’ll save you money, especially if you have a lot of similarly configured containers.

Slow Cooker Power Consumption

When I was looking to buy a slow cooker I didn’t find much on specific power usage. I guess it depends on your model, but even general figures were hard to find. Now I’ve got one, here’s the deal;

Morphy Richards 3.6 litre crockpot (bought from Argos in Sept 2010)

High 160w
Low 118w
Warm 37w

The readings I took for cooking a full meal for 10.5 hours (high at the start, the low for most of it, then warm for a while), used 1.23kw of electricity. There’s no thermostat so it idles along at whatever power setting you’ve chosen. At today’s UK energy prices you might be looking at 12p per kw of energy, and therefore about 15p to slow cook a meal.

It’d be interesting to know how much energy it would take to cook this purely on the hob, in some ways I’m guessing it might be cheaper, but the convenience of the slow cooker for some meals is what appeals.. plus 15p isn’t exactly expensive.