Hi, Michael I don't quite understand what do you mean by "round trip back to the client". In my understanding, as the RegionServer and TaskTracker can be the same node, MR don't have to pull data into client and then process. And you also mention the "unnecessary overhead", can you explain a little bit what operations or data processing can be seen as "unnecessary overhead".
Thanks yong On Mon, Feb 18, 2013 at 10:35 AM, Michael Segel <michael_se...@hotmail.com> wrote: > Why? > > This seems like an unnecessary overhead. > > You are writing code within the coprocessor on the server. Pessimistic code > really isn't recommended if you are worried about performance. > > I have to ask... by the time you have executed the code in your co-processor, > what would cause the initial write to fail? > > > On Feb 18, 2013, at 3:01 AM, Prakash Kadel <prakash.ka...@gmail.com> wrote: > >> its a local read. i just check the last param of PostCheckAndPut indicating >> if the Put succeeded. Incase if the put success, i insert a row in another >> table >> >> Sincerely, >> Prakash Kadel >> >> On Feb 18, 2013, at 2:52 PM, Wei Tan <w...@us.ibm.com> wrote: >> >>> Is your CheckAndPut involving a local or remote READ? Due to the nature of >>> LSM, read is much slower compared to a write... >>> >>> >>> Best Regards, >>> Wei >>> >>> >>> >>> >>> From: Prakash Kadel <prakash.ka...@gmail.com> >>> To: "user@hbase.apache.org" <user@hbase.apache.org>, >>> Date: 02/17/2013 07:49 PM >>> Subject: coprocessor enabled put very slow, help please~~~ >>> >>> >>> >>> hi, >>> i am trying to insert few million documents to hbase with mapreduce. To >>> enable quick search of docs i want to have some indexes, so i tried to use >>> the coprocessors, but they are slowing down my inserts. Arent the >>> coprocessors not supposed to increase the latency? >>> my settings: >>> 3 region servers >>> 60 maps >>> each map inserts to doc table.(checkAndPut) >>> regionobserver coprocessor does a postCheckAndPut and inserts some rows to >>> a index table. >>> >>> >>> Sincerely, >>> Prakash >>> >> > > Michael Segel | (m) 312.755.9623 > > Segel and Associates > >
