How Discord Stores Billions of Messages Using Cassandra
I&#x27;m one of the people who nagged you on the redis post, and particularly expressed skepticism that such a transition would&#x27;ve been necessary. I haven&#x27;t read this yet, but I just want to say thanks for actually following up to that thread and posting it. Looking forward to it!<p>---------<p>EDIT: Just read the post, and while it provides a good perspective on Discord&#x27;s rationale to introduce Cassandra in the first place and does a great job pointing out some unexpected pitfalls, it doesn&#x27;t specifically respond to replacing Redis with Cassandra due to clustering difficulty, per the prior thread. [0] Redis is only specifically called out as something they &quot;didn&#x27;t want to use&quot;, which I guess is probably the most honest answer.<p>The bucket logic applied to Cassandra seems like it could&#x27;ve been applied to redis + a traditional permanent storage backend nearly as easily. The biggest downside here would be crossing the boundary for cold data, but that&#x27;s a pretty common thing that we know lots of ways to address, right? And Cassandra effectively has to do the same thing anyway, it just abstracts it away.<p>Again, I&#x27;m left wondering what specific value Cassandra brings to the table that couldn&#x27;t have been brought by applying equal-or-lesser effort to the system they already had.<p>I also found it amusing that they&#x27;re already contemplating the need to transition to a datastore that runs on a non-garbage-collected platform.<p>[0] <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=13368754" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=13368754</a>