I tried to answer to a comment that was deleted, probably due to the form. Instead of deleting my answer, I want to share the reworded critics and my answers.
> Why not using Riak and adding an S3 API around it.
Riak was developed by a company named Basho that went bankrupt some years ago, the software is not developed anymore. In fact, we do no need to add an S3 API around Riak KV, Basho even released "Riak Cloud Storage"[0] that exactly does this: provide an S3 API on top of Riak KV architecture. We plan to release a comparison between Garage and Riak CS, Garage has some interesting features that Riak CS does not have! In practice, implementing an object store on top of a DynamoDB-like KV store is not that straightforward. For example, Exoscale, a cloud provider went this way for their first implementation of their KV store, Pithos[1], but rewrote it later as you need special logic to handle your chunks (they did not publish Pithos v2).
> Most apps don't have S3 support
We are maintaining in our documentation an "integration" section listing all the compatible applications. Garage already works with Matrix, Mastodon, Peertube, Nextcloud, Restic (an alternative to Borg), Hugo and Publii (a static site generator with a GUI). These applications are only a fraction of all existing applications, but our software is targeted at its users/hosters.
> A distributed system is not necessarily highly available
I will not fight on the wording: we come from an academic background where the term "distributed computing" has a specific meaning that may differ outside. In our field, we define models where we study systems made of processes that can crash. Depending on your algorithms and the properties you want, you can prove that your system will work despite some crashes. We want to build software on these academic foundations. This is also the reason we put "Standing on the shoulders of giants" on our front page and linking to research papers. To put it in a nutshell, one critic we address to other software is that sometimes they lack theoretical/academic foundations that lead to unexpected failures/more work to sysadmins. But on the theoretical point, Basho and Riak were exemplary and a model for us!
I also had some things to answer to that comment which I'll put back here for the record.
> I have been building distributed systems for 20 years, and they are not more reliable. They are probabilistically more likely to fail.
It depends on what kind of faults you want to protect against. In our case, we are hosting servers at home, meaning that any one of them could be disconnected at any time due to a power outage, a fiber being cut off, or any number of reasons. We are also running old hardware where individual machines are more likely to fail. We also do not run clusters composed of very large numbers of machines, meaning that the number of simultaneous failures that can be expected actually remains quite low. This means that the choices made by Garage's architecture make sense for us.
But maybe your point was about the distinction between distributed systems and high availability, in which case I agree. Several of us have studied distributed systems in the academic setting, and in our vocabulary, distributed systems almost by definition includes crash-tolerance and thus making systems HA. I understand that in the engineering community the vocabulary might be different and we might orient our communication more towards presenting Garage as HA thanks to your insight, as it is one of our core, defining features.
> However, this isn't it. This is distributed S3 with CRDTs. Still too application-specific, because every app that wants to use it has to be integrated with S3. They could have just downloaded something like Riak and added an S3 API around it.
Garage is almost that, except that we didn't download Riak but made our own CRDT-based distributed storage system. It's actually not the most complex part at all, and most of the developpement time was spent on S3 compatibility. Rewriting the storage layer means that we have better integration between components, as everything is built in Rust and heavily depends on the type system to ensure things work well together. In the future, we plan to reuse the storage layer we built for Garage for other projects, in particular to build an e-mail storage server.
We still intend to publish the successor to Pithos at some point, it has seen a large overhaul in terms of how metadata is handled and relies on a in-house system for blob storage.
> Why not using Riak and adding an S3 API around it.
Riak was developed by a company named Basho that went bankrupt some years ago, the software is not developed anymore. In fact, we do no need to add an S3 API around Riak KV, Basho even released "Riak Cloud Storage"[0] that exactly does this: provide an S3 API on top of Riak KV architecture. We plan to release a comparison between Garage and Riak CS, Garage has some interesting features that Riak CS does not have! In practice, implementing an object store on top of a DynamoDB-like KV store is not that straightforward. For example, Exoscale, a cloud provider went this way for their first implementation of their KV store, Pithos[1], but rewrote it later as you need special logic to handle your chunks (they did not publish Pithos v2).
> Most apps don't have S3 support
We are maintaining in our documentation an "integration" section listing all the compatible applications. Garage already works with Matrix, Mastodon, Peertube, Nextcloud, Restic (an alternative to Borg), Hugo and Publii (a static site generator with a GUI). These applications are only a fraction of all existing applications, but our software is targeted at its users/hosters.
> A distributed system is not necessarily highly available
I will not fight on the wording: we come from an academic background where the term "distributed computing" has a specific meaning that may differ outside. In our field, we define models where we study systems made of processes that can crash. Depending on your algorithms and the properties you want, you can prove that your system will work despite some crashes. We want to build software on these academic foundations. This is also the reason we put "Standing on the shoulders of giants" on our front page and linking to research papers. To put it in a nutshell, one critic we address to other software is that sometimes they lack theoretical/academic foundations that lead to unexpected failures/more work to sysadmins. But on the theoretical point, Basho and Riak were exemplary and a model for us!
[0]: https://docs.riak.com/riak/cs/2.1.1/index.html [1]: https://github.com/exoscale/pithos