Cassandra 6 adds ACID transactions via Accord — we test all four options
The road to ACID transactions in Cassandra 6
Cassandra 6.0 is set to introduce Accord, a transactional protocol bringing ACID guarantees to the open-source database. We set up a three-node cluster on the pre-release branch and tested four transactional options: plain updates, BATCH, lightweight transactions (LWT), and Accord. Plain updates violated the balance invariant 939 times in one run; BATCH mostly held, but occasionally produced inconsistent sums due to timestamp collisions. Accord, the new protocol, aims to fix these issues with full ACID semantics.
Ok, so plain Cassandra doesn’t make for a great bank.
- cyberpunk
I'm sure for some workloads, cassandra is 'ideal' or at least was 10 years ago.
What I can say though (as someone running thousands of cpus worth of cassandra at the moment); is that I deeply dislike this database. It's an operational nightmare, and I will not miss it even the slightest bit if it goes away forever.
On the other hand, I'm sure glad to see a bit of life in cassandra dev, it seems to have been dormant for a while; but would I pick it for new applications in 2026? No. I'd strongly recommend against using it unless you have the money to pay for a dedicated team to maintain it, and even then just.. No.
- javier2
Thanks for this, really looking forward to the release of Accord