A Brief History of High Availability • Hacker News Board

Re: A Brief History of High Availability

#21

Post by mattzito » Fri, Oct 05, 2018, 1:38 PM UTC

tyingq wrote: post #20

mattzito wrote: post #18

Earlier quoted context omitted.

Hey, for once my former life designing HA infrastructure is actually useful! The reality is that hardware HA was almost always terrible. Of the platforms you described: - Sun had no hardware HA ever, down to the unfathomable design that all of their E-class machines had only one power cord. They had SOME hotswap hardware, but the rules were byzantine - it couldn't be the first processor board, and it couldn't be the…

"Compaq had the NonStop servers, which ran OpenVMS...but it was all delivered in software" NonStop/Guardian had nothing to do with OpenVMS. And the hardware was certainly purpose built for HA, including redundant, lockstepped CPUs, disk controllers, etc.

You are 100% correct - in my haste, I conflated the old Tandem hardware line with the OpenVMS clustering platform. My mistake, I’ll see if I can edit my post.

Re: A Brief History of High Availability

#22

Post by icedchai » Fri, Oct 05, 2018, 2:06 PM UTC

mattzito wrote: post #18

KaiserPro wrote: post #8

Hmm, I think potted history is more correct... There is no mention hardware here. HP, Compaq, IBM and Sun all produced hardware with HA ability. Meaning that normal software could be run on two or more nodes, and should one break, it'd fall over with no loss of data, or outages. Here is a (contrived) video where they literally blow up a server stack: https://www.youtube.com/watch?v=qMCHpUtJnEI You can do this with VM…

Hey, for once my former life designing HA infrastructure is actually useful! The reality is that hardware HA was almost always terrible. Of the platforms you described: - Sun had no hardware HA ever, down to the unfathomable design that all of their E-class machines had only one power cord. They had SOME hotswap hardware, but the rules were byzantine - it couldn't be the first processor board, and it couldn't be the…

I'm pretty sure I had an E3500, back in the late 90's, that had two power supplies. I may be misremembering...

No, you are correct. That second power supply was apparently for "peripherals only", not the main CPUs... http://www.tech-specifications.com/SunServers/E3500.html !

Re: A Brief History of High Availability

#23

Post by rstupek » Fri, Oct 05, 2018, 2:53 PM UTC

mattzito wrote: post #18

KaiserPro wrote: post #8

Hmm, I think potted history is more correct... There is no mention hardware here. HP, Compaq, IBM and Sun all produced hardware with HA ability. Meaning that normal software could be run on two or more nodes, and should one break, it'd fall over with no loss of data, or outages. Here is a (contrived) video where they literally blow up a server stack: https://www.youtube.com/watch?v=qMCHpUtJnEI You can do this with VM…

Hey, for once my former life designing HA infrastructure is actually useful! The reality is that hardware HA was almost always terrible. Of the platforms you described: - Sun had no hardware HA ever, down to the unfathomable design that all of their E-class machines had only one power cord. They had SOME hotswap hardware, but the rules were byzantine - it couldn't be the first processor board, and it couldn't be the…

Compaq ServerPro had HA ability with a hot spare server connected to the primary with automatic failover well before the Tandem acquisition.

Re: A Brief History of High Availability

#24

Post by feyman_r » Fri, Oct 05, 2018, 3:00 PM UTC

For anyone interested in learning more about HA and consistency, I found this book very interesting: https://dataintensive.net/. The author does a great job developing an intuition for progress made along with trade-offs at each stage.

Re: A Brief History of High Availability

#25

Post by SomeHacker44 » Fri, Oct 05, 2018, 3:24 PM UTC

mattzito wrote: post #18

KaiserPro wrote: post #8

Hmm, I think potted history is more correct... There is no mention hardware here. HP, Compaq, IBM and Sun all produced hardware with HA ability. Meaning that normal software could be run on two or more nodes, and should one break, it'd fall over with no loss of data, or outages. Here is a (contrived) video where they literally blow up a server stack: https://www.youtube.com/watch?v=qMCHpUtJnEI You can do this with VM…

Hey, for once my former life designing HA infrastructure is actually useful! The reality is that hardware HA was almost always terrible. Of the platforms you described: - Sun had no hardware HA ever, down to the unfathomable design that all of their E-class machines had only one power cord. They had SOME hotswap hardware, but the rules were byzantine - it couldn't be the first processor board, and it couldn't be the…

What about true HA hardware, for example like Tandem, or the systems on the Space Shuttle, etc.? A discussion of those systems from the 70s, 80s and 90s seems appropriate (but I am not knowledgeable enough to start it).

Re: A Brief History of High Availability

#26

Post by RightMillennial » Fri, Oct 05, 2018, 3:34 PM UTC

mjlee wrote: post #11

As mentioned on HN previously, B&H (a large New York based photography store) do not take online orders in accordance with Jewish holidays. https://news.ycombinator.com/item?id=12183263

They also will not take online orders during the Sabbath (i.e., Friday evening until Saturday evening). It's peculiar that they enforce it for online checkout. It's a quality website nonetheless.

Re: A Brief History of High Availability

#27

Post by forapurpose » Fri, Oct 05, 2018, 4:28 PM UTC

mattzito wrote: post #18

KaiserPro wrote: post #8

Hmm, I think potted history is more correct... There is no mention hardware here. HP, Compaq, IBM and Sun all produced hardware with HA ability. Meaning that normal software could be run on two or more nodes, and should one break, it'd fall over with no loss of data, or outages. Here is a (contrived) video where they literally blow up a server stack: https://www.youtube.com/watch?v=qMCHpUtJnEI You can do this with VM…

Hey, for once my former life designing HA infrastructure is actually useful! The reality is that hardware HA was almost always terrible. Of the platforms you described: - Sun had no hardware HA ever, down to the unfathomable design that all of their E-class machines had only one power cord. They had SOME hotswap hardware, but the rules were byzantine - it couldn't be the first processor board, and it couldn't be the…

Your comment leaves the impression that IBM mainframes, not to mention high-end Unix systems from Sun, IBM, and HP, commonly had problems that would crash the machines and had no better availability than my desktop or perhaps a $3K server.

Perhaps it was meant as hyperbole, but it would be interesting and valuable to hear some of the nuance from someone with your experience.

IME talking to people, many, especially mainframe operators, would disagree. My direct experience with mid-range Compaq/HP servers has been excellent - it's hard to remember a box going down unless I commanded it to. I don't think I replaced any except due to age or warranty expiration.

Re: A Brief History of High Availability

#28

Post by Exuma » Fri, Oct 05, 2018, 6:30 PM UTC

Hey bro you want to hit this? Whats the WORST name for a company we can come up with??

Re: A Brief History of High Availability

#29

Post by mmt » Fri, Oct 05, 2018, 6:41 PM UTC

forapurpose wrote: post #27

mattzito wrote: post #18

Earlier quoted context omitted.

Hey, for once my former life designing HA infrastructure is actually useful! The reality is that hardware HA was almost always terrible. Of the platforms you described: - Sun had no hardware HA ever, down to the unfathomable design that all of their E-class machines had only one power cord. They had SOME hotswap hardware, but the rules were byzantine - it couldn't be the first processor board, and it couldn't be the…

Your comment leaves the impression that IBM mainframes, not to mention high-end Unix systems from Sun, IBM, and HP, commonly had problems that would crash the machines and had no better availability than my desktop or perhaps a $3K server. Perhaps it was meant as hyperbole, but it would be interesting and valuable to hear some of the nuance from someone with your experience. IME talking to people, many, especially ma…

> it's hard to remember a box going down unless I commanded it to

This could be a form of the law-of-large-numbers at work. If each customer only has a single box, and the failure rate is .1%, then 999 customers will never have a failure to remember, compared to the 1 who will.

What does it look like if each customer has 1000 boxes?

Re: A Brief History of High Availability

#30

Post by twic » Fri, Oct 05, 2018, 7:09 PM UTC

mjlee wrote: post #11

As mentioned on HN previously, B&H (a large New York based photography store) do not take online orders in accordance with Jewish holidays. https://news.ycombinator.com/item?id=12183263

I once worked with a bank where a server we depended on was only available from 0800 to 1500, then 1530 to 1700. I think that's the only time i've ever had to build around a computer which took a tea break.