Inline On Mon, Sep 23, 2013 at 6:15 PM, Shahab Yunus <shahab.yu...@gmail.com>wrote:
> Yeah, I saw that. In fact that is why I recommended that to you as I > couldn't infer from your email that whether you have already gone through > that source or not. Yes, i was aware of that article. But my read pattern is slighty different from that article.We are using HBase as DataSource for a RestFul service. Even though if my range scan finds 400 rows with a specified timerange. I only return top 20 for one rest request. So, if in case i do bucketing(lets say bucket=10) then i will need to fetch 20 results from each bucket and then i will have to do a merge sort on the client size and return final 20. You can assume that i need to return the 20rows sorted by timestamp. > A source, who did the exact same thing and discuss it > in much more detail and concerns aligning with yours (in fact I think some > of the authors/creators of that link/group are members here of this > community as well.) Do you know what the outcome of their experiment? Do you have any link for that? Thanks for your time and help. > > Regards, > Shahab > > > On Mon, Sep 23, 2013 at 8:41 PM, anil gupta <anilgupt...@gmail.com> wrote: > > > Hi Shahab, > > > > If you read my solution carefully. I am already doing that. > > > > Thanks, > > Anil Gupta > > > > > > On Mon, Sep 23, 2013 at 3:51 PM, Shahab Yunus <shahab.yu...@gmail.com > > >wrote: > > > > > > > > > > > http://blog.sematext.com/2012/04/09/hbasewd-avoid-regionserver-hotspotting-despite-writing-records-with-sequential-keys/ > > > > > > Here you can find the discussion, trade-offs and working code/API (even > > for > > > M/R) about this and the approach you are trying out. > > > > > > Regards, > > > Shahab > > > > > > > > > On Mon, Sep 23, 2013 at 5:41 PM, anil gupta <anilgupt...@gmail.com> > > wrote: > > > > > > > Hi All, > > > > > > > > I have a secondary index(inverted index) table with a rowkey on the > > basis > > > > of Timestamp of an event. Assume the rowkey as <TimeStamp in Epoch>. > > > > I also store some extra(apart from main_table rowkey) columns in that > > > table > > > > for doing filtering. > > > > > > > > The requirement is to do range-based scan on the basis of time of > > > > event. Hence, the index with this rowkey. > > > > I cannot use Hashing or MD5 digest solution because then i cannot do > > > range > > > > based scans. And, i already have a index like OpenTSDB in another > > table > > > > for the same dataset.(I have many secondary Index for same data set.) > > > > > > > > Problem: When we increase the write workload during stress test. Time > > > > secondary index becomes a bottleneck due to the famous Region > > HotSpotting > > > > problem. > > > > Solution: I am thinking of adding a prefix of { (<TimeStamp in > > > Epoch>%10) = > > > > bucket} in the rowkey. Then my row key will become: > > > > <Bucket><TimeStamp in Epoch> > > > > By using above rowkey i can at least alleviate *WRITE* problem.(i > don't > > > > think problem can be fixed permanently because of the use case > > > requirement. > > > > I would love to be proven wrong.) > > > > However, with the above row key, now when i want to *READ* data, for > > > every > > > > single range scans i have to read data from 10 different regions. > This > > > > extra load for read is scaring me a bit. > > > > > > > > I am wondering if anyone has better suggestion/approach to solve this > > > > problem given the constraints i have. Looking for feedback from > > > community. > > > > > > > > -- > > > > Thanks & Regards, > > > > Anil Gupta > > > > > > > > > > > > > > > -- > > Thanks & Regards, > > Anil Gupta > > > -- Thanks & Regards, Anil Gupta
