MongoDB vs. PostgreSQL vs. ScyllaDB: Tractian’s Experience
1–5 of 5 posts
Re: MongoDB vs. PostgreSQL vs. ScyllaDB: Tractian’s Experience
#2But Scylla doesn't offer the same consistency guarantees as Mongo, right? You can shard pretty wide with Mongo and still read your own writes, while my understanding is Scylla is eventually consistent?
Re: MongoDB vs. PostgreSQL vs. ScyllaDB: Tractian’s Experience
#3But Scylla doesn't offer the same consistency guarantees as Mongo, right? You can shard pretty wide with Mongo and still read your own writes, while my understanding is Scylla is eventually consistent?
Scylla has "tunable" consistency[1][2][3], so it's possible to get consistency without too much of a performance hit, and still be resilient to some failures.
[1]: https://www.scylladb.com/glossary/eventual-consistency/
[2]: https://docs.scylladb.com/stable/cql/consistency.html
[3]: https://docs.scylladb.com/stable/cql/consistency-calculator....
Re: MongoDB vs. PostgreSQL vs. ScyllaDB: Tractian’s Experience
#4But Scylla doesn't offer the same consistency guarantees as Mongo, right? You can shard pretty wide with Mongo and still read your own writes, while my understanding is Scylla is eventually consistent?
Scylla has "tunable" consistency[1][2][3], so it's possible to get consistency without too much of a performance hit, and still be resilient to some failures. [1]: https://www.scylladb.com/glossary/eventual-consistency/ [2]: https://docs.scylladb.com/stable/cql/consistency.html [3]: https://docs.scylladb.com/stable/cql/consistency-calculator....
Nice, thanks! I haven't used it yet.
Re: MongoDB vs. PostgreSQL vs. ScyllaDB: Tractian’s Experience
#5But Scylla doesn't offer the same consistency guarantees as Mongo, right? You can shard pretty wide with Mongo and still read your own writes, while my understanding is Scylla is eventually consistent?
Scylla has "tunable" consistency[1][2][3], so it's possible to get consistency without too much of a performance hit, and still be resilient to some failures. [1]: https://www.scylladb.com/glossary/eventual-consistency/ [2]: https://docs.scylladb.com/stable/cql/consistency.html [3]: https://docs.scylladb.com/stable/cql/consistency-calculator....
On top of this, ScyllaDB also has "Lightweight Transactions" (LWT) that use Paxos to do a compare-and-set (CAS) read-before-write. This is important for strict linearizability. You can think of it really roughly as "single partition ACID."
They are also implementing a Raft infrastructure upon which they will be able to do strong consistency transactions in the future.
https://www.scylladb.com/tech-talk/the-future-of-consensus-i...
[Disclosure: I used to work at ScyllaDB]