Re:Amazon Launches Managed Cassandra Service
by senderista on Tuesday December 03, 2019 @05:13PM
(#21697380)
I struggle to think of any similarities, actually. I think DynamoDB's design makes it clear that the era of decentralized architecture/eventual consistency at Amazon has come and gone. DHTs just don't make sense in the data center.
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Re:Amazon Launches Managed Cassandra Service
by wikibob on Tuesday December 03, 2019 @07:32PM
(#21698464)
Can you elaborate on this?
Do you mean that amazon is tending towards strong or externalizable consistency now?
I’ve always noticed AWS products tend towards eventual consistency, and Google Cloud offerings are almost all strongly consistent.
For example S3 is eventually consistent for read after write (if it’s not the first write). Google cloud storage is strongly consistent for read after all writes.
Re:Amazon Launches Managed Cassandra Service
by senderista on Wednesday December 04, 2019 @01:12AM
(#21700008)
I think the goal is for S3 to "eventually" be strongly consistent. I heard one of S3's designers say that they shouldn't have opted for eventual consistency in retrospect.
Re:Amazon Launches Managed Cassandra Service
by grogenaut on Wednesday December 04, 2019 @12:42AM
(#21699900)
Not sure what you mean, DDB provides both strong and eventual consistency, now in 2 fashions with transactions. 3 if you include cross region replication.
There's definitely still a DHT sitting under there.
Re:Amazon Launches Managed Cassandra Service
by senderista on Wednesday December 04, 2019 @01:09AM
(#21699997)
No, it's something like a hash-partitioned primary-backup-replicated distributed database. S3 is much closer to a DHT.
Re:Amazon Launches Managed Cassandra Service
by manigandham on Wednesday December 04, 2019 @01:21AM
(#21700044)
There's no real difference between a DHT (distributed hash table) and a hash-partitioned distributed database. It's the same concept. Apache Cassandra is considered an implementation of a DHT.