Michael Ellery 2013-02-07, 23:47
Ted Yu 2013-02-08, 00:34
Michael Ellery 2013-02-08, 01:02
-Re: column count guidelines
Ted Yu 2013-02-08, 01:09
Thanks Michael for this information.
FYI CDH4 (as of now) is based on HBase 0.92.x which doesn't have the two
features I cited below.
On Thu, Feb 7, 2013 at 5:02 PM, Michael Ellery <[EMAIL PROTECTED]> wrote:
> There is only one CF in this schema.
> Yes, we are looking at upgrading to CDH4, but it is not trivial since we
> cannot have cluster downtime. Our current upgrade plans involves additional
> hardware with side-by side clusters until everything is exported/imported.
> On Feb 7, 2013, at 4:34 PM, Ted Yu wrote:
> > How many column families are involved ?
> > Have you considered upgrading to 0.94.4 where you would be able to
> > from lazy seek, Data Block Encoding, etc ?
> > Thanks
> > On Thu, Feb 7, 2013 at 3:47 PM, Michael Ellery <[EMAIL PROTECTED]>
> >> I'm looking for some advice about per row CQ (column qualifier) count
> >> guidelines. Our current schema design means we have a HIGHLY variable CQ
> >> count per row -- some rows have one or two CQs and some rows have
> >> of 1 million. Each CQ is on the order of 100 bytes (for round numbers)
> >> the cell values are null. We see highly variable and too often
> >> unacceptable read performance using this schema. I don't know for a
> >> that the CQ count variability is the source of our problems, but I am
> >> suspicious.
> >> I'm curious about others' experience with CQ counts per row -- are there
> >> some best practices/guidelines about how to optimally size the number of
> >> CQs per row. The other obvious solution will involve breaking this data
> >> into finer grained rows, which means shifting from GETs to SCANs - are
> >> there performance trade-offs in such a change?
> >> We are currently using CDH3u4, if that is relevant. All of our loading
> >> done via HFILE loading (bulk), so we have not had to tune write
> >> beyond using bulk loads. Any advice appreciated, including what metrics
> >> should be looking at to further diagnose our read performance
> >> Thanks,
> >> Mike Ellery
Michael Ellery 2013-02-08, 04:34
Marcos Ortiz 2013-02-08, 05:38
Dave Wang 2013-02-08, 16:58
Marcos Ortiz Valmaseda 2013-02-08, 01:08
Asaf Mesika 2013-02-08, 16:25
Ted Yu 2013-02-08, 17:50