VA VISTA Cloud Services - CPRS AppStream

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rrichards

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Apr 6, 2024, 3:09:26 PMApr 6
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Regarding the article on cloud migration of  VA VistA to the VA Enterprise Cloud:

What the author of the article means by "virtualization" is along the lines of "virtual desktop". It does not involve rewriting applications a web applications.

AWS has a web streaming approach to virtualizing applications. This technology streams the screen of the application over the web. This is a no-code solution to transform thick clients to web-accessible clients:


AWS AppStream implementation in VA:  CPRS and VISTA were co-hosted in the same AWS cloud host.  The RPC connection between the two therefore did not need to traverse many layers of routers, gateways, and networking  a thousand miles from the data center to the desktop.   It was no suprise that AppStream CPRS response timing was up to an order of magnitude faster than running CPRS locally as a thick client. 



Nancy Anthracite

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Apr 6, 2024, 3:48:10 PMApr 6
to Hardhats, rrichards
I am actually surprised if CPRS is faster because office applications and access
to files at the VA office worker type site I work at are much slower for ordinary
users after the VA applications were migrated to the cloud. That might be
because of the network available is in rented office space.

--
Nancy Anthracite

ivaldes

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Apr 6, 2024, 10:02:19 PMApr 6
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Can confirm speed increase. That was our experience when we went to all cloud-based Astro-CPRS many years ago with our (very) upgraded CPRS variant. It solved a lot of problems, not just performance ones. Management, security, poor local internet. We get style points for using open-source guacamole stack to achieve this through the browser. :-) But lose points by still using in the mix Windows Server instead of WINE :-(

-- IV
-- Astronaut, LLC

rrichards

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Apr 9, 2024, 9:16:17 AMApr 9
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We tested AppStream CPRS at Valley Coastal Bend TX  VAMC  (one of the first VAMCs to migrate VistA to the AWS cloud).
One particular 'hotspot' of latency for clinicians was loading a complex multi-layered TIU note for annual checkups.
In their locally installed (Windows  Desktop) CPRS it took over 29 seconds to load.
When they used the remotely installed (AWS cloud-hosted CPRS) and then streamed it to their desktop using AWS AppStream, it took 1.2 seconds.

This proved our hunch that it was indeed VA's networking infrastructure as the root cause for CPRS latency.
When we  eliminated all the layers of routers, gateways,.etc) and connected CPRS directly to VISTA within the same AWS cloud,
all of this network latency disappeared.

What we actually "rediscovered" was the original archtecture of VISTA/CPRS, which were designed to be physically closely
connected to each other (i.e. both running within the same VA hospital).  As VA moved the Vista servers away from the
medical centers, it introduced latency.

Kimball Bighorse

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Apr 10, 2024, 7:40:33 PMApr 10
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Is CPRS/VistA/AppStream hosted in AWS' us-east region I presume? So about 1700 miles of latency to Valley Coastal?

-kb

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