Hacker News Reader

Hacker News

Comment by onlypositive | Hacker News Reader

Parent Full thread

onlypositive

Cassandra was initially released in 2008.

Back in 2004 I was running larger MySQL databases than yelp has now:

https://www.enterpriseappstoday.com/stats/yelp-statistics.ht...

> That is not something you'd be able to put on one single database in 2004.

Sorry, but it was, plenty of companies had much larger databases back then running plain old master slave replication.

But even if it wasn't: just don't run it all on one db? Nothing says you need to be able to join on the restaurant table and the comments table. Put them on different servers. That's all you're doing with Casandra anyway.

View on HN

If you're not just running it all on one db, why do you have to have all of your different DBs be on the same DB software?

I used to work at Yelp, and at least at that time, a big use case of Cassandra was basically for what were essentially materialized views created from log data. At that point in time, MySQL or logs were the "sources of truth", but there were enough transactions going on that it made sense to have things like Cassandra around too for some of the other use cases.

Postgres didn't ship built-in replication until 2010, and prior replication solutions like Slony were not options I would have enjoyed building a business around.

MySQL shipped replication in 2000. This whole conversation is some webscale copium bullshit. I'm out.

Cassandra is highly-available, your suggestion is not.

MySQL master slave replication has failover, so it is technically highly available, especially if you have multiple slaves. It was also best practice back then so this argument is kind of weird.

Also, whether you need a highly available database for a company like yelp is an implementation detail.

Oh no, the database is down, how will Jonny decide where to go for lunch now?!

Cassandra is more close to AP whereas MySQL with clustering is more like CP. So they serve different purpose. See this nice discussion on Stackoverflow: https://stackoverflow.com/questions/36404765/why-isnt-rdbms-...

> Also, whether you need a highly available database for a company like yelp is an implementation detail.

You surely know better than them what they need, that's impressive.

Reply on news.ycombinator.com