That's not true. Scylla does multi-threading. Scylla is a single process, single address space. It does pin the threads to individual hyper threads but there are additional other workers in the background as well.
Many need SVB, we (ScyllaDB) received a great service from them in the past. Later on we just used them as one of our banks, obviously, going forward, we're diversifying our services.
The problem for startups is that debt provider who are also a bank require to move most of the business to that provider. It's not the case other types of debt providers.
w.r.t debt - everybody use this mechanism, doesn't matter if you're small or big.
There is no magic behind Scylla, mainly lots of hard work, hundreds of years of engineering, based on the former C* design which is based on Dynamo/Bigtable.
The JVM is part of the problem, not all of it. The main issue is that it hides the hardware and makes tracing harder - instruction level and block level. At Scylla we strive for efficiency, every operation is tagged with a priority class for the CPU and I/O schedulers. Folks are welcome to read the blogs about those topic. Lots of details and hard work
ScyllaDB excels in throughput and latency, we have also a better compaction algorithm that saves 37% of storage compared to C*.
Usually one can replace lots of small nodes with gigantic nodes that have more
resources and it allows much better management.
To run 100PB Scylla will need more than 300 nodes, even thousands but definitely
not what Apple throw at the problem.
Listening to SQLite creator podcast (https://corecursive.com/066-sqlite-with-richard-hipp/# ), it does feel that Glauber is right about weird collaboration standards. The guy is against gmail, git, etc. Fossil may be better for SQlite today, w/o many contributors, that's the problem Glauber is trying to solve
This is indeed what we (ScyllaDB) do, pretty much everywhere.
It works great for 95% of our users. Discord wanted to add a level
of guarantee since they observed a too high level of local disk failures.
Am ScyllaDB but Marc did completely independent work.
The client vcpus don't matter that much, the experiment compares
the server side, the client shouldn't suck.
When we test ScyllaDB or other DBs, we run benchmarks for hours and days. This is just a stateless, static http daemon, so short timing is reasonable.
The whole intent is to make it a learning experience, if you wish to reproduce, try it yourself. It's aligned with past measurements of ours and also with former Linux optimizations by Marc.
Good point. This is more of a tcp stack comparison between the kernel and userspace. Seastar has a sharded (per core) stack, which is very beneficial when the number of threads is high
What's amazing is that the seastar tcp stack hasn't been changed over the past 7 years, while the kernel received plenty of improvements (in order to close the gap vs kernel bypass mechanisms).
Still, for >> 99% of users, there is no need to bypass the kernel.
ScyllaDB uses Seastar as an engine and the DynamoDB compatible API use HTTP parsing, so this use case is real. Of course the DB has much more to do than this benchmark with a static http reply but Scylla also uses many more core in the server, thus it is close to real life. We do use the kernel's tcp stack, due to all of its features and also since we don't have capacity for a deeper analysis.
Some K/V workloads are affected by the networking stack and we recently seen issues if we chose not the ideal interrupt mode (multiqueue vs single queue in small machines)
LWT on Scylla is much faster than its C* implementation.
As one of the co-founders, I agree that SQL and the relational model are superior than CQL. However, either they do not scale or even when they do (newsql), they are 10x slower and handle less volume, etc.
The right way to use NoSQL is when you know your scaling model. LWT helps you to serialize important tables.
Scylla consistently makes improvements in operations, consistency and functionality, so more to come, see what we'll announce at the summit next month
Correct but Jepsen focuses on consistency and correctness and not on destructive. Scylla is exposed to range tombstone issue like many other LSMs. We recently have been improving them - check the most recent issues: https://github.com/scylladb/scylla/issues?q=is%3Aissue+is%3A...