Almost every Cassandra feature has some surprising behavior
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Almost every Cassandra feature has some surprising behavior
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Re: Almost every Cassandra feature has some surprising behavior
#2Thank you for changing the name of the title. The default title is clickbait which I find very surprising given this is a tech post and IMO the audience for such posts hates these titles.
Re: Almost every Cassandra feature has some surprising behavior
#3Thank you for changing the name of the title. The default title is clickbait which I find very surprising given this is a tech post and IMO the audience for such posts hates these titles.
It's a parody of clickbait.
Re: Almost every Cassandra feature has some surprising behavior
#4This Team Used Apache Cassandra Without Reading The Fine Manual… You Won’t Believe What Happened Next
“You honestly expected that adopting a data store at your scale would not require you to learn all of its internals?”
Re: Almost every Cassandra feature has some surprising behavior
#5The thing is that contrary to many other tools, you can't run Cassandra with almost any of its default settings (maybe besides ports). In most tools you'll need to tweak a few defaults, with Cassandra you need to thoroughly read the docs on every little configuration in the server and schema definitions (especially if you're working in multiple DCs), you'll always find a little surprise if you skim through it.
It's also almost mandatory to read the internal design docs of cassandra even if you're not the admin but just working with it. And modelling data is a lost less trivial than it looks - and almost always not what you assume.
Anyway, this is the best talk I've seen on Cassandra data modeling even if you know Cassandra but not on an expert level. I made sure everyone on my team saw it at least once. https://www.youtube.com/watch?v=qphhxujn5Es
Re: Almost every Cassandra feature has some surprising behavior
#6I love that the article pokes fun at click-bait articles ... I'm not a Cassandra user but having used several other NoSQL solutions, I'm not at all surprised that this team, who dove into a new technology without caution, was surprised.
Re: Almost every Cassandra feature has some surprising behavior
#7The thing is that contrary to many other tools, you can't run Cassandra with almost any of its default settings (maybe besides ports). In most tools you'll need to tweak a few defaults, with Cassandra you need to thoroughly read the docs on every little configuration in the server and schema definitions (especially if you're working in multiple DCs), you'll always find a little surprise if you skim through it. It's a…
The one that is really irksome is the COMPACT STORAGE one, as it is explicitly disrecommended and deprecated by the Cassandra documentation. I have not yet gotten around to using Cassandra in any production environment, nor have I done any large-scale tests, and it has been a while since I delved deeply into the data model, but I remember looking at this part of the storage system and thinking it was "wrong", but wondered if I was just misunderstanding things, given how clearly and strongly it was discouraged. Flipping through the presentation you just linked, they are using all the new features and there are no slides that mention compact storage. "30x", as reported in this article, is clearly non-trivial: what is your take?
Re: Almost every Cassandra feature has some surprising behavior
#8The thing is that contrary to many other tools, you can't run Cassandra with almost any of its default settings (maybe besides ports). In most tools you'll need to tweak a few defaults, with Cassandra you need to thoroughly read the docs on every little configuration in the server and schema definitions (especially if you're working in multiple DCs), you'll always find a little surprise if you skim through it. It's a…
The one that is really irksome is the COMPACT STORAGE one, as it is explicitly disrecommended and deprecated by the Cassandra documentation. I have not yet gotten around to using Cassandra in any production environment, nor have I done any large-scale tests, and it has been a while since I delved deeply into the data model, but I remember looking at this part of the storage system and thinking it was "wrong", but won…
I haven't dealt with the ops side of running our clusters, and the details are not fresh in my mind, so I don't remember much about the storage engines. But we encountered surprises on almost any front when taking C* to production.
Re: Almost every Cassandra feature has some surprising behavior
#9This Team Used Apache Cassandra Without Reading The Fine Manual… You Won’t Believe What Happened Next “You honestly expected that adopting a data store at your scale would not require you to learn all of its internals?” These aren't even internals, these are basic facts about Cassandra.
I do believe Cassandra requires a much more intimate knowledge of its internals if you want to do anything serious with it - more so than any other database I've worked with.
Re: Almost every Cassandra feature has some surprising behavior
#10"We were actually hoping that Cassandra could store things more compactly than our raw data"
Why in hell would you think that?
CQL is not SQL? No shit. Actually, the docs pretty clearly spell that out. Anyone with even a cursory knowledge of Cassandra or any big data store would know you need to understand how the system works, and what it's limitations are before you model your data for the system.
COMPACT STORAGE is for backwards compatibility. Turn it on and you are turning off CQL3: http://docs.datastax.com/en/cql/3.0/cql/cql_reference/create... http://www.datastax.com/dev/blog/whats-new-in-cql-3-0
Counters are only usable for things where you don't care if the counter gets increased exactly one time. It is for stuff that doesn't really matter, like "likes" on a page or something.
I'm not even reading "Check Your Row Size: Too Wide, Too Narrow, or Just Right?" because measuring the number of columns max and the ~10MB performance limit is trivial to do and this is a datastore designed by data scientists for people who are willing to do the very little bit of knowledge gain required.
This whole article reads like someone who decided to incorporate Cassandra without actually spending any time learning how to do it correctly before trying to do it.
"He said, “You honestly expected that adopting a data store at your scale would not require you to learn all of its internals?” He has a point."
No shit.