Bill Wear
on 9 January 2020
MAAS readying enhanced network testing and link checking
Enhanced MAAS Network Testing and Link Checking
With the upcoming release of MAAS 2.7, Metal-as-a-Service has gained new network testing and link-checking features. These features identify broken and slow network links when you try to commission machines, notifying you when there are discrepancies. In this release, we also offer the capability to test networking in a configurable way, even using your own scripts.
MAAS tests whether links are connected or disconnected. Previously, when commissioning, you couldn’t detect unplugged cables. Now you can. You will have to take a couple of steps for existing MAAS deployments: First, you will have to upgrade to 2.7, then run commissioning again to see if a link is disconnected. But you no longer have to puzzle over what’s broken when this happens.
Second, MAAS makes sure you’re getting the most out of your link speed. As servers and hardware get faster — 10G, 40G, even 100G NICS — the chances increase that you might plug your 10G NIC into a 1G switch, for example. Previously, with MAAS, you’d be stuck with the speed of the slowest link, but there wasn’t a way to verify your link speed without recommissioning. Depending on your physical hardware, that might still be an issue, but the MAAS UI can now warn you if your interface is connected to a link slower than what the interface supports. And all information shown in the UI is available via the API, as well. You can still replace a slow switch without recommissioning.
Third, MAAS allows you to configure network connectivity testing in a number of ways. If you’ve used MAAS, you know that if can’t connect to the rack controller, deployment can’t complete. Now MAAS can check connectivity to the rack controller and warn you if there’s no link, long before you have to try and debug it it. For example, if you can’t connect to your gateway controller, traffic can’t leave your network. MAAS can now check this link and recognize that there’s no connectivity, which alleviates a lot of annoying (and sometimes hard-to-detect) network issues.
Fourth, Internet connectivity testing has been greatly expanded. Previously, MAAS gave a yes/no link check during network testing. Now you can give a list of URLs or IP addresses to check. In the ephemeral environment, standard DHCP is still applied, but when network testing runs, we can apply your specific configuration for the duration of the test. While all URLs / IPs are tested with all interfaces, we do test each of your interfaces individually, including breaking apart bonded NICS and testing each side of your redundant interfaces. You can also run different tests on each pass, e.g., a different set of URLs, although each run would be a different testing cycle. For testing individual interfaces, you can use the API.
Of course, the main feature network coming in 2.7 is improved — and customisable — network testing. You can now create your own commissioning scripts and tests related to networking. You can create your own network tests (e.g., a network throughput test) and run them during the network testing portion of the MAAS workflow. There are no particular restrictions on these scripts, so you can test a wide variety of possible conditions and situations.