Failed to answer the original question - 15 tablet servers, 32 tablets/splits.
On Fri, Nov 9, 2012 at 11:52 AM, Anthony Fox <[email protected]> wrote: > I've tried a number of different settings of table.split.threshold. I > started at 1G and bumped it down to 128M and the cf scan is still ~30 > seconds for both. I've also used less rows - 00000 to 99999 and still see > similar performance numbers. I thought the column family bloom filter > would help deal with large row space but sparsely populated column space. > Is that correct? > > > On Fri, Nov 9, 2012 at 11:49 AM, William Slacum < > [email protected]> wrote: > >> I'm more inclined to believe it's because you have to search across 10M >> different rows to find any given column family, since they're randomly, and >> possibly uniformly, distributed. How many tablets are you searching across? >> >> >> On Fri, Nov 9, 2012 at 11:45 AM, Anthony Fox <[email protected]>wrote: >> >>> Yes, there are 10M possible partitions. I do not have a hash from value >>> to partition, the data is essentially randomly balanced across all the >>> tablets. Unlike the bloom filter and intersecting iterator examples, I do >>> not have locality groups turned on and I have data in the cq and the value >>> for both index entries and record entries. Could this be the issue? Each >>> record entry has approximately 30 column qualifiers with data in the value >>> for each. >>> >>> >>> On Fri, Nov 9, 2012 at 11:41 AM, William Slacum < >>> [email protected]> wrote: >>> >>>> I guess assuming you have 10M possible partitions, if you're using a >>>> relatively uniform hash to generate your IDs, you'll average about 2 per >>>> partition. Do you have any index for term/value to partition? This will >>>> help you narrow down your search space to a subset of your partitions. >>>> >>>> >>>> On Fri, Nov 9, 2012 at 11:39 AM, William Slacum < >>>> [email protected]> wrote: >>>> >>>>> That shouldn't be a huge issue. How many rows/partitions do you have? >>>>> How many do you have to scan to find the specific column family/doc id you >>>>> want? >>>>> >>>>> >>>>> On Fri, Nov 9, 2012 at 11:26 AM, Anthony Fox <[email protected]>wrote: >>>>> >>>>>> I have a table set up to use the intersecting iterator pattern. The >>>>>> table has about 20M records which leads to 20M column families for the >>>>>> data section - 1 unique column family per record. The index section of >>>>>> the table is not quite as large as the data section. The rowkey is a >>>>>> random padded integer partition between 0000000 and 9999999. I turned >>>>>> bloom filters on and used the ColumnFamilyFunctor to get performant >>>>>> column family scans without specifying a range like in the bloom filter >>>>>> examples in the README. However, my column family scans (without any >>>>>> custom iterator) are still fairly slow - ~30 seconds for a column family >>>>>> batch scan of one record. I've also tried RowFunctor but I see similar >>>>>> performance. Can anyone shed any light on the performance metrics I'm >>>>>> seeing? >>>>>> >>>>>> Thanks, >>>>>> Anthony >>>>>> >>>>>> >>>>> >>>> >>> >> >
