Most are - irony of irony is that when Delta had its big outage due to CrowdStrike, dealtamatic/deltaterm was still running just fine, but no one could get into it because all of their windows machines were locked out.
At the core of most airlines is a customized version of IBM TPF, its very reliable and highly available, its all of the other stuff that breaks down.
We will in time find out what grounded AS, I wouldnt be surprised if its some sort of middleware connecting their iPads to the CRS they use for ticketing operations, but it could also be something as simple as their weight and balance application going offline.
AS is a fairly well run airline (as are DL, AA and UA) with a heterogeneous mix of systems in service, ideally this heterogeneous nature should make for a more resilient system but it also can lead to single points of failure when you have to glue too many different systems together.
excellent point. at tmobile (circa 2014) it required 87 APIs be hit to turn on a new subscriber. if the 34th API failed, the subscriber had to wait and start over clogging up the stores. at the core only 3 or 4 of those APIs were crucial to start the service and the rest could have been fine with eventual consistency. who is ticketed for what flight is the core, the rest dealing with plane can be handled manually just like the small airplanes do it, manual weight & balance, flight planning, etc. but Alaska chooses not to do that and is ok losing millions of dollars per day disrupted while losing customers because they do not care. and not hiring a safety officer for years proves they do not care.
At the core of most airlines is a customized version of IBM TPF, its very reliable and highly available, its all of the other stuff that breaks down.
We will in time find out what grounded AS, I wouldnt be surprised if its some sort of middleware connecting their iPads to the CRS they use for ticketing operations, but it could also be something as simple as their weight and balance application going offline.
AS is a fairly well run airline (as are DL, AA and UA) with a heterogeneous mix of systems in service, ideally this heterogeneous nature should make for a more resilient system but it also can lead to single points of failure when you have to glue too many different systems together.