RonDB receives ARM64 support and large transaction support

 RonDB is the base platform for all applications in Hopsworks. Hopsworks is a machine learning platform featuring a Feature Store that can be used in online applications as well as offline applications.

This means that RonDB development is driven towards ensuring that operating RonDB in this environment is the best possible.

RonDB is designed for millions of small transactions reading and writing data. However occasionally applications perform rather large transactions. Previous versions of RonDB had some weaknesses in this area. The new versions of RonDB now supports also large transactions although the focus is still on many smaller transactions.

Designing this new support of large transactions required a fairly large development effort. To do this in a stable release is a challenge, therefore it was decided to combine this effort with a heavy testing period focused on fixing bugs.

This effort has been focused on achieving three objectives. First to stabilise the new RonDB 21.04 releases which is the stable release of RonDB. Second, to stabilise the next RonDB release at the same level as RonDB 21.04. Third, we also wanted the same level of support for ARM64 machines.

We are now proud to release RonDB 21.04.3, a new stable release of RonDB that supports much larger transactions. Since the release of RonDB 21.04.1 in July 2021 we have fixed more than 50 bugs in RonDB and we are very satisfied with the stability also on ARM64 machines.

The original plan was to release the next version of RonDB in October 2021, however we didn't want to release a new version with any less stability than the RonDB 21.04 release. Thus instead we release this new version of RonDB now, RonDB 22.01.0.

ARM64 support covers both RonDB 21.04.3 and RonDB 22.01.0. RonDB is now also supported on both Linux and Mac OS X and on Windows it is supported using WSL 2 (Linux on Windows) on Windows 11. We have extensively tested RonDB on the following platforms:

1. Mac OS X 11.6 x86_64
2. Mac OS X 12.2 ARM64
3. Windows WSL 2 Ubuntu x86_64
4. Ubuntu 21.04 x86_64
5. Oracle Linux 8 Cloud Developer version ARM64

It is used in production on AWS and Azure and has been extensively tested also on GCP and Oracle Cloud.

As part of the new RonDB release we have also updated the documentation of RonDB at docs.rondb.com. Among other things it contains a new section on Contributing to RonDB that shows how you can build, test and develop extensions to RonDB. In the documentation you will also find an extensive list of the improvements made in the two new RonDB releases.

ARM64 support is still in beta phase, our plan is to make it available for production use in Q2 2022. There are no known bugs, but we want to give it a bit more time before we assign it to production workloads. This includes adding more test machines and also performing benchmarks on ARM64 VMs.

Our experience with ARM64 machines so far says that it is fairly stable, but it isn't yet at the same level as x86, it is possible to find bugs in the compilers, the support around it is however maturing very quickly and not surprising the support on Mac OS X is here leading the way since Mac OS X has fully committed its future on ARM. We have also great help of participating in the OCI ARM Accelerator program providing access to ARM VMs in the Oracle Cloud making it possible to test on Oracle Linux using ARM with both small and large VMs.

RonDB 22.01.0 comes with a set of new features:

1. Now possible to scale reads using locks onto more threads
2. Improved placement of primary replicas to enable
3. All major memory areas now managed by global memory manager
4. Even more flexibility in thread configurations
5. Removing a scalability hog in index statistics handling
6. Merged with MySQL Cluster 8.0.28

You can either download RonDB tarballs from https://github.com/logicalclocks/rondb or from https://repo.hops.works/master, for exact links to the various versions of the binary tarballs see Release Notes on each version.

Running Linux in Windows 11

 Most people that know me, also knows how I really don't like working with Windows. I actually worked with Microsoft products already in the 1980s, so I haven't been able to stay away from them completely.

Developing MySQL on a Windows platform haven't been so easy since building MySQL on Windows is difficult and also there are a number of issues in running even the simple test suites of MySQL.

At the same time the world is full of developers with only Windows as their development platform. So when I read about the possibility to run Linux inside Windows 11 I thought it was time to test if development of RonDB could now be done on Windows.

My 9-year old laptop needed replacement, so I went ahead and found a nice Windows laptop at a fair price. I wanted to test the very latest developments that I could find in Windows 11. Since the laptop was delivered with Windows 10 I did an unusual thing, I wanted to upgrade the OS :)

This wasn't exactly easy, took a few hours, but eventually after upgrading Windows 10 a few times and searching for a Windows 11 download I eventually found such a one using Google on the Microsoft website. After a couple of upgrades I was at the latest Windows 11 release.

Installing Linux was quite easy, it was one simple command. I installed an Ubuntu variant.

Most of the installation went ok. The graphics installation didn't work, but the installation of terminal software was good enough to test at least the testing part. For development I use graphical Vim, so this needs to wait for a working version of the graphical parts of Linux (or using a Windows editor, but likely not since they tend to add extra line feeds on the line).

Downloading the RonDB git tree went fine. Compiling RonDB required installing a number of extra packages, but that is normal and will happen also in standard Linux (build essentials, cmake, openssl dev, ncurses, bison, ..).

Running the MTR test suite also went almost fine. I had to install zip and unzip as well for this to work.

Running the MTR test suite takes about an hour and here I found a few challenges. First I had to find the parallelism it could survive. I was hoping on parallelism of 12 (which in reality for RonDB means 6 parallel tests running). But in reality it was only stable with a parallelism of 6.

However since I wasn't sitting by the Windows laptop while the test was running the screen saver decided to interfere (although I had configured it to go into screen save mode after 4 hours). Unfortunately the screen saver decided that the Linux VM should be put to sleep and this meant that all test cases running when the screen saver hit in failed. Seems like this is a new issue in WSL 2 not existing in WSL 1.

However I think that I am still happy with what I saw. Running an operating system inside another and making it feel like Linux is a part of Windows isn't an easy task. So here I must give some kudos to the development team. So if they continue working on this integration I think that I am going to get good use of my new laptop.

I must admit that I don't fully understand how they have solved the issue of running Linux inside Windows. But it definitely looks like the Linux kernel makes use of Windows services to implement the Linux services. Running top in an idle system is interesting, there is only a few init processes and a bash process. So obviously all the Linux kernel processes are missing and presumably implemented inside Windows in some fashion.

The best part is that the Linux VM configuration isn't static. The Linux VM could make use of all 16 CPUs in the laptop, but it could also allow Windows to grab most of them. So obviously the scheduler can handle both Linux and Windows programs.

Memory-wise the Linux VM defaults to being able to grow to a maximum of 80% of the memory in the laptop. However in my case top in Linux constantly stated that it saw 13.5 GB of memory in a machine with 32 GB of memory. I saw some post on internet stating that Linux can return memory to Windows if it is no longer needed. Not sure I saw this, but it is a new feature, so feel confident it will be there eventually.

So at least working with RonDB on Windows 11 is going to be possible. How exactly this will pan out I will write about in future worklogs. At least it is now possible that I can do some development in Windows, it was more than 30 years ago I last had a development machine with a Microsoft OS, so to me, Linux on Windows is definitely making Windows as a platform a lot more interesting.

My development environments have shifted a bit over the years. It started with a mix of Microsoft OSs and Unix and some proprietary OSs in the 80s. In the 90s I was mostly working in Solaris on Sun workstations. Early 2000's I was working with Linux as development machine. But since 2003 I have been working mostly on Mac OS X (and of course lots of test machines on all sorts of platforms).