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Comment · 6 months ago
Comment · 1 year ago
Ursa is available across all major cloud providers (GCP, Azure, AWS). It also supports pluggable write ahead log storage. For latency relaxed workloads, we use object storage to get the cost down. So it works with AWS S3, GCP GCS, Azure Blob Store. For latency sensitive workloads, we use Apache BookKeeper which is a low-latency replicated log storage. This allows us to support workloads ranging from milliseconds to sub-seconds. You can tune it based on latency and cost requirements.
Comment · 1 year ago
There seems to be a confusion here.

Pulsar has been widely adopted in many mission-critical business-facing systems like billing, payment, transaction processing, or used a unified platform that consolidate enterprises diverse streaming & messaging use cases. It has quite a lot of adoptions from F500 companies, hyperscalers, to startups.

Kafka is used for in data ingestion and streaming pipeline. Kafka protocol itself is great. However, the implementation has its own challenges.

Both Pulsar and Kafka are great open source projects and their protocols are designed for different use cases. We have seen many different companies use both technologies.

Ursa is the underlying streaming engine that we re-implemented to be leaderless and lakehouse-native so that we can better leverage the current cloud infrastructure and natively integrate with broader lakehouse ecosystem. It is the engine we used to support both in our product offerings.

Comment · 1 year ago
Comment · 1 year ago
We also love Kafka as a protocol. However, the implementation can be evolved to adopt the current cloud infrastructure and and rethought based on the modern lakehouse paradigm. That was one of the reasons we created Ursa.
Comment · 1 year ago
I am one of the co-founders of StreamNative.

Currently Ursa is only available in our cloud service. But we do plan to open-source the core soon. Stay tuned.

Comment · 11 years ago
Ah, just happened to see those two blog posts together in same place. Those are really good posts on explaining replication scheme of Apache BookKeeper.

One thing to add on Flavio's blog post. Readers of a log (ledger) agree on LastAddConfirmed (lac), which LAC could be thought of 'commit' message in most of consensus protocol. In replicated log, commit means making data visible for readers.

BookKeeper doesn't enforce 'commit' like what other consensus protocol does. Instead it exposes the core elements of a consensus protocol as primitives and let applications decide things such as when to commit, how often to commit. Readers could use API (readerLastConfirmed) to catch up to latest 'commit' data. Controlling when to commit is the way how DistributedLog uses BookKeeper to tune end-to-end latency for different types of workloads: for latency-sensitive workloads like database, it does aggressive commits, for analytics workload, it does periodical commits to get benefits (such as reducing bandwidth by compression) by grouping.

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