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sh00s

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Joined
Wed, Sep 12, 2018, 4:06 PM UTC
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Recent public activity

  1. comment
    Comment #18006186

    Ah, I think you may be talking about the repeatable reads property? All readers in LogDevice are guaranteed to see the same records in the same order (aside from trimmed data).

  2. comment
    Comment #18006153

    LogDevice clients do notify sequencers if they have seen newer epochs, which would cause a sequencer reactivation, which indeed resolves the issue within the context of a single cl…

  3. comment
    Comment #18005501

    > Which are the cases where consistency is compromised then? If a client of the log needs consistency, it needs to ensure that it has seen all previous updates to a log before maki…

  4. comment
    Comment #18004661

    Yes, reads are not released (i.e. are blocked) until sealing is complete. We call the minimal set of nodes sufficient to serve reads for a log (the same set is needed for sealing t…

  5. comment
    Comment #17991750

    A log in LogDevice is roughly equivalent to a Kafka partition.

  6. comment
    Comment #17986193

    yes, in LogDevice it's called "sealing". However, as it stands, a newly activated sequencer won't wait for sealing on the old epoch to complete before taking new writes - in the tr…

  7. comment
    Comment #17981289

    splitting data into partitions would mean there's no total order on that data anymore, right?

  8. comment
    Comment #17981279

    LogDevice has many-to-many rebuilding as well, and typically data for a log (similar to partition in Kafka) is spread relatively uniformly over the (potentially large, much bigger …

  9. comment
    Comment #17981242

    No, compression is disabled by default. You can enable compression either on the storage layer, or by enabling batching and compression on the sequencer, or by using the buffered w…

  10. comment
    Comment #17981216

    Some strengths of LogDevice include: - It's designed to work with a large number of logs (roughly equivalent to partitions in Kafka), hundreds of thousands per cluster is common. -…

  11. comment
    Comment #17981191

    LogDevice is payload-agnostic and doesn't inspect the value of the binary blobs it stores. If your writer is allowed to write according to ACLs, LogDevice will happily take writes …