Hacker News Reader

Comment by plq | Hacker News Reader

I will be honest and just say this: As a Linux guy who has negligible familiarity with the Windows Server technology, this post doesn't make much sense to me.

What is the Linux equivalent of this operation? apt-get dist-upgrade? Now that Windows 10 onward is rolling release (is it?) is this the last time SE staff is going to have to go through this?

This caught my attention:

> Putting the 2019 server into the existing 2012 cluster – as expected, this fails due to the operating systems being different.

How can a website be this tightly coupled with the operating system it's running on? Shouldn't Microsoft be blamed that their operating systems are not backwards-compatible? To my knowledge, Microsoft goes to extreme lengths to assure backwards-compatibility of the userland apps. What went wrong here?

View on HN

> How can a website be this tightly coupled with the operating system it's running on?

The post is about their database servers, not the site. Microsoft SQL Server’s high availability and disaster recovery solutions are built atop Windows Server Failover Clustering, which comes with a lot of gotchas. For example, for over a decade, all of the members of a cluster had to be the same major version of Windows. That made upgrades not just difficult, but impossible: you had to build a brand new cluster from scratch every time and then migrate over to it, and destroy the old cluster when you were done.

Microsoft does indeed go to lengths to assure backwards compatibility. This isn’t a compatibility issue - it’s an upgrade process issue.

(Source: I did SQL Server HA/DR work for years, including helping Stack out along the way, but abandoned HA/DR work when it became kinda untenable. Now I focus on the performance tuning side instead.)

Windows 10 was designed for desktops, not as a server software. Windows Server 2003/2008/2012/2014/2019 etc is for servers and they don't subscribe to Windows 10 rolling release. They have their release and support cycles. People rarely upgrade.

I have upgraded a website from Windows 2003, to Windows 2008, to Windows 2012 and now it is running on Windows 2019. I jumped 2014 and 2016 because upgrades weren't necessary for my needs. Each time, I only spent 1 hour maximum to migrate the system. I am not even a server guy.

You mean 2016 right, not 2014? Or are you talking about SQL versions?

Yes. I meant Windows Server 2016. Thanks for the correction.

The Linux equivalent would be upgrading a database cluster from CentOS 5 to 7, or Ubuntu 12.04 to 18.04.

On a production cluster, you aren't just going to "apt dist-upgrade" and be done, you're going to need to deal with versions of all sorts of things under the hood changing versions as well. In the SO case, they were at least able to keep the database versions the same, but it sounds like some other things were incompatible between the two OSes that prevented them from directly clustering together.

to be fair if you have a production cluster of elasticsearch or postgres you can't just upgrade the DATABASE technology without interrupting the cluster. BUT you can upgrade the OS from CentOS 5 to 7 without a problem. And the Elasticsearch/Postgres Cluster would still be fine

Depends on a lot of things... Often you'll be using the OS provided postgres package, so upgrading from 5 to 7 will probably also involve a big database version update. Do you have any associated tooling or services? They might need updates to work with newer libraries or software updates, such as Python 2.5 to 2.8. Etc...

Over the last couple decades, I've done something around 100 of these sorts of upgrades for clients of a managed hosting service I used to run, and they were rarely simple OS upgrades. Lots of planning and testing went into them.

That's the sort of upgrade this article seems to be about, I'm not sure if it's because SQL Server is tightly integrated with some OS-provided services that were incompatible, but it was certainly more involved than a base OS running only the database and just installing the same database on the new OS.

I have an NVMe drive that was rendered non-bootable by a Linux kernel upgrade, and a new Dell bios was needed to get it to boot. Some of these issues happen on linux in general as well.

Non-rolling linux releases (such as ubuntu) run into all sorts of strange issues during a dist upgrade, and you may end up with database servers sufficiently different to prevent them from clustering together.

Windows server has always been versioned differently from desktop windows with 8 LTS versions since 2003.

Upgrading in a production environment is not as easy as apt-get upgrade. There are tests that need to be run, version incompatibilities that need to be investigated, and plenty of other things that need to be done. The complexity varies but it's almost never as simple as running a little command and going home. To claim otherwise just because it's Windows we're taking about is being specious.

Reply on news.ycombinator.com