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ScyllaDB Open Source 3.0

scylladb.com

31–40 of 73 posts

Re: ScyllaDB Open Source 3.0

#31

Earlier quoted context omitted.

https://docs.scylladb.com/using-scylla/cassandra-compatibili... The big remaining item is lightweight transactions.

What's a light weight transaction?

A compare-and-set request. E.g., I can read version 3 of a row, and write version 4 if the current version is still 3, so that if someone else writes version 4 I don't clobber whatever they just did.

Re: ScyllaDB Open Source 3.0

#34

Anyone using this in production? Any thoughts or tips on how to adapt traditional MongoDB workflows to this?

The best person to talk to about this is @Ultrabug (Twitter and Github), CTO of Numberly, who moved from MongoDB to Scylla:

Fixed link: https://www.scylladb.com/tech-talk/numberly-on-joining-billi...

Re: ScyllaDB Open Source 3.0

#35

Earlier quoted context omitted.

https://docs.scylladb.com/using-scylla/cassandra-compatibili... The big remaining item is lightweight transactions.

What's a light weight transaction?

Pythian blog on the topic; note that Cassandra relies on Paxos as a consensus algorithm. Scylla will be using Raft: https://blog.pythian.com/lightweight-transactions-cassandra/

Re: ScyllaDB Open Source 3.0

#36

According to their https://www.scylladb.com/open-source/ page: Server License: - Free Software Foundation’s GNU AGPL v3.0 - Commercial licenses are also available. Contact us for more information. Driver Licenses: - Apache Cassandra drivers: Apache License v2.0 Third-party drivers: - Licenses will vary. See the individual driver documentation for details. Documentation License: - Creative Commons Attribution-ShareAli…

AGPL is an open source license as per OSI definition which you yourself point to!

You don't have to take my word for it, just check out their own site:

https://opensource.org/licenses/AGPL-3.0

The licenses you are talking about, such as MIT or Apache, are called _permissive licenses_ whereas AGPL is a _copyleft license_. However, both types of licenses can be open source licenses, if they fill the OSI requirements.

Re: ScyllaDB Open Source 3.0

#37

Earlier quoted context omitted.

What the heck? You are right, AGPL is listed, yet clearly violates https://opensource.org/osd-annotated definition. Could somebody explain this to me?

It conforms with OSD for the same reason GPL v2/v3 does. As I understand it, AGPL simply treats "networked access" as a subset of "linking". There's a ton of legal grey area that hasn't been tested or has been hand waved away (do I have to open source my web application if it connects to a database that is AGPL licensed?)

AGPL treats "networked access" as "distribution", not "linking".

With the GPL, you are required to make your modifications available as GPL if you distribute the modified program. This creates a loophole for ASPs, which can modify GPL’d code, but because they offer it as a service (and don’t distribute the program), they don’t have to share the modifications. AGPL closes this loophole by explicitly saying that network access is considered as “distribution”.

So no, you don't need to make your web application AGPL. Just like you don't make all your applications running on Linux GPL just because they happen to communicate with the kernel over system calls. Copyleft licenses are relevant only if your code is a derivative work of the original.

Re: ScyllaDB Open Source 3.0

#40
post #39

Anyone using this in production? Any thoughts or tips on how to adapt traditional MongoDB workflows to this?

We are (Zenly) and have been since 1 1/2 years.

Indeed! And for those interested in seeing how Zenly made the switch:

https://www.scylladb.com/2017/11/29/zenly-database-replaceme...

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