if you have rows like 10k and get 100 column per row, this gonna choke the cluster...been there. if you really still have to use multiget_slice, try slice your data before calling multiget_slice and check if your cluster read request pending increase... try to slow down the client sending request to the cluster if the pending going up. :)
On Tue, Dec 11, 2012 at 6:15 AM, Wei Zhu <wz1...@yahoo.com> wrote: > Well, not sure how parallel is multiget. Someone is saying it's in > parallel sending requests to the different nodes and on each node it's > executed sequentially. I didn't bother looking into the source code yet. > Anyone knows it for sure? > > I am using Hector, just copied the thrift definition from Cassandra site > for reference. > > You are right, the count is for each individual row. > > Thanks. > -Wei > > ------------------------------ > *From:* "Hiller, Dean" <dean.hil...@nrel.gov> > *To:* "user@cassandra.apache.org" <user@cassandra.apache.org>; Wei Zhu < > wz1...@yahoo.com> > *Sent:* Monday, December 10, 2012 1:13 PM > *Subject:* Re: multiget_slice SlicePredicate > > What's wrong with multiget…parallel performance is great from multiple > disks and so usually that is a good thing. > > Also, something looks wrong, since you have list<binary> keys, I would > expect the Map to be Map<binary, list<ColumnOrSuperColumn>> > > Are you sure you have that correct? IF you set range to 100, it should be > 100 columns each row but it never hurts to run the code and verify. > > Later, > Dean > PlayOrm Developer > > > From: Wei Zhu <wz1...@yahoo.com<mailto:wz1...@yahoo.com>> > Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" < > user@cassandra.apache.org<mailto:user@cassandra.apache.org>>, Wei Zhu < > wz1...@yahoo.com<mailto:wz1...@yahoo.com>> > Date: Monday, December 10, 2012 2:07 PM > To: Cassandr usergroup <user@cassandra.apache.org<mailto: > user@cassandra.apache.org>> > Subject: multiget_slice SlicePredicate > > I know it's probably not a good idea to use multiget, but for my use case, > it's the only choice, > > I have question regarding the SlicePredicate argument of the multiget_slice > > > The SlicePredicate takes slice_range which takes start, end and range. I > suppose start and end will apply to each individual row. How about range, > is it a accumulative column count of all the rows or to the individual row? > If I set range to 100, is it 100 columns per row, or total? > > Thanks for you reply, > -Wei > > multiget_slice > > * > map<string,list<ColumnOrSuperColumn>> multiget_slice(list<binary> keys, > ColumnParent column_parent, SlicePredicate predicate, ConsistencyLevel > consistency_level) > > > > >
