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https://issues.apache.org/jira/browse/CASSANDRA-4775?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13681748#comment-13681748
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Aleksey Yeschenko commented on CASSANDRA-4775:
----------------------------------------------
Was looking into possible variations of the original idea - the first comment
in this issue, and how we could implement it to allow true idempotent
client-retriable counter updates, and came with this so far:
https://gist.github.com/iamaleksey/fa36552409dc2aa70bee
Cons:
- has significant overhead per-cell - needs to store the timeuuid in the column
name
- has the obvious overhead of having multiple cells per single counter
- requires either forcing QUORUM writes (so that merge could get away with
QUORUM reads) or ALL reads for the merge. Now, this is probably true for any
merge process for any variation of 'each update = new cell, with periodic
merges'
- requires special-casing on the read path
- maintaining backward compatibility isn't going to be fun
Pros:
- updates are truly idempotent (within the configurable write window)
- allows counters to coexist with regular columns in regular tables
- allows including counters in (non-logged) batches
- requires a lot less overall special-casing
- easily supports min/max/avg/sum_sq functions
Not sure if this is viable considering that '"retryable" is at the very bottom
of my priorities here' but maybe there is something useful in there anyway.
> Counters 2.0
> ------------
>
> Key: CASSANDRA-4775
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4775
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Arya Goudarzi
> Assignee: Aleksey Yeschenko
> Labels: counters
> Fix For: 2.1
>
>
> The existing partitioned counters remain a source of frustration for most
> users almost two years after being introduced. The remaining problems are
> inherent in the design, not something that can be fixed given enough
> time/eyeballs.
> Ideally a solution would give us
> - similar performance
> - less special cases in the code
> - potential for a retry mechanism
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