This change has been successfully rolled out, we're saving 50-70% on our default deployments, yay! "bbl up" with newer bbl versions will change your default VM types catalog. If you run CATS, read on...

Newer versions of BBL starting with 8.4.91 will deploy more modern and efficient VM sizes by default. Along the way we encountered a problem where the default configuration is less reliable in passing CATS, which makes sense because there's a lot less hardware deployed. A change from CATS timeout_scale: 1 to timeout_scale: 2 fixes the issue and the CATS still pass when run in parallel with 12 nodes only about 25% slower (which is acceptable). We plan to fix CATS timeout defaults eventually such that this timeout scaling configuration option is not required.

Using the 1AZ cf-deployment ops-file, the CATS now will always fail when run in parallel due to the smaller standardized diego cell size. To work around this, BBL v8.4.93 standardizes the "medium" (4 cores, 16GB) and "large" (8 cores, 32GB) VM sizes and introduces a "medium-highmem" (4 cores, 32GB) size. These additional standard sizes give operators and CF authors additional sizes to choose from for diego cells, such as this newly introduced ops file designed to make parallel CATS testing fast+reliable in a single-AZ minimal configuration.