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  1. Couchbase Server
  2. MB-7761 Add stats for all operations to memcached
  3. MB-7419

Disk reads for append/prepend/incr/decr/gal/gat operations are not correctly accounted in estimating the cache miss ratio

    Details

    • Type: Technical task
    • Status: Open
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: 2.0, 3.0
    • Fix Version/s: bug-backlog
    • Component/s: couchbase-bucket
    • Security Level: Public
    • Labels:
      None

      Description

      append/prepend/incr/decr/gal/gat operations require disk reads for non-resident items, but those disk reads are not added to the cache miss ratio stat. This causes the cache miss ratio to go beyond 100%, which is wrong.

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        Activity

        Hide
        chiyoung Chiyoung Seo added a comment -

        Yeah, that's a good point. It's not good to use the stats from two different layers to calculate the cache miss ratio. Let's discuss this more when I'm back from the vacation. I don't think we should fix it for 2.0.1

        Show
        chiyoung Chiyoung Seo added a comment - Yeah, that's a good point. It's not good to use the stats from two different layers to calculate the cache miss ratio. Let's discuss this more when I'm back from the vacation. I don't think we should fix it for 2.0.1
        Hide
        perry Perry Krug added a comment -

        Updated for get-and-touch and get-and-lock.

        Do we also need to consider different things for "full ejection" mode? i.e, we probably want to indicate that an 'add' operation would always result in a cache miss. There are others too...

        Show
        perry Perry Krug added a comment - Updated for get-and-touch and get-and-lock. Do we also need to consider different things for "full ejection" mode? i.e, we probably want to indicate that an 'add' operation would always result in a cache miss. There are others too...

          People

          • Assignee:
            Unassigned
            Reporter:
            chiyoung Chiyoung Seo
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            Dates

            • Created:
              Updated:

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