It’s recommended in the docs over the Buffer table, and is pretty much invisible to the end user.
At ClickHouse Inc itself, this scaled far beyond millions of rows per second: https://clickhouse.com/blog/building-a-logging-platform-with...
We went from the get go to that infrastructure for multiple reasons in the first place:
* Having a durable buffer before ensures if you have big spikes that gets eaten by the buffer, not OLAP which when it is powering your online dashboard you want to keep responsive. Clickhouse cloud now has compute/compute that addresses that but open source users' don't.
* When we shipped this for the first time, clickhouse did not have the async buffering in place, so not doing some kind of buffered inserts was forwned upon. * As oatsandsugar mentioned, since them we also shipped direct insert where you don't need a kafka buffer if you don't want it
* From an architecture standpoint, with that architecture you can have multiple consumers
* Finally, having kafka enables having streaming function written in your favorite language vs using SQL. Definitely will be less performance to task ratio, but depending on the task might be faster to setup or even you can do things you couldn't directly in the database.
Disclaimer I am the CTO at Fiveonefour
Altinity is addressing this with Project Antalya builds. We have extended open source ClickHouse with stateless swarm clusters to scale queries on shared Iceberg tables.
Disclaimer: CEO of Altinity
It’s mainly focused on the insert batching which is why I was drawing attention to async_insert.
I think it’s worth highlighting the incremental transformation that CH can do via the materialised views too. That can often replace the need for a full blown streaming transformation pipelines too.
IMO, I think you can get a surprising distance with “just” a ClickHouse instance these days. I’d definitely be interested in articles that talk about where that threshold is no longer met!
If you need to ensure that you have super durable writes, you can consider, but I really think it’s not something you need to reach for at first glance
https://news.ycombinator.com/item?id=45651098
One of the reasons we streaming ingests is because we often modify the schema of the data in stream. Usually to conform w ClickHouse best practices that aren't adhered to in the source data (restrictive types, denormalization, default not nullable, etc).