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Zookeeper >> mail # dev >> Re: [jira] [Commented] (ZOOKEEPER-1568) multi should have a non-transaction version


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Re: [jira] [Commented] (ZOOKEEPER-1568) multi should have a non-transaction version
I actually think there is a valid use case for this. Mostly for performance
reasons. Because a multi is one transaction, it causes less permuation on
the distributed and replicated state of zookeeper than multiple individual
operations not in a multi.

With a Multi:
- You only pay the cost of the RPC overhead once rather than on each
individual operation
- You get one flush of the leader channel rather than multiple ones for
each write operation
- A multi will case one new snapshot/log to be generated rather than
multiple ones for each operation

There are other reasons that make this a good reason too that are not
performance based. e.g., if it makes the programmer's job easier to use a
multi with these semantics, then that's a win.

In other distributed databases I've worked on, we used different
terminology to disinguish between a multi op that all succeed/fail vs one
that does not. We used the term "Batch" to imply we were batching up
operations but there was no guarantee they'd all succeed/fail.

On Wed, Oct 24, 2012 at 10:44 AM, Jimmy Xiang (JIRA) <[EMAIL PROTECTED]>wrote:

>
>     [
> https://issues.apache.org/jira/browse/ZOOKEEPER-1568?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13483372#comment-13483372]
>
> Jimmy Xiang commented on ZOOKEEPER-1568:
> ----------------------------------------
>
> Yes, that's what we are using now. It is working fine. I was thinking if
> there is still room for improvement.
>
> > multi should have a non-transaction version
> > -------------------------------------------
> >
> >                 Key: ZOOKEEPER-1568
> >                 URL:
> https://issues.apache.org/jira/browse/ZOOKEEPER-1568
> >             Project: ZooKeeper
> >          Issue Type: Improvement
> >            Reporter: Jimmy Xiang
> >
> > Currently multi is transactional, i.e. all or none.  However, sometimes,
> we don't want that.  We want all operations to be executed.  Even some
> operation(s) fails, it is ok. We just need to know the result of each
> operation.
>
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