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Brandon Williams edited comment on CASSANDRA-2893 at 12/22/11 1:50 AM: ----------------------------------------------------------------------- Maybe a chart isn't the best way to look at this. First, let me note that I mislabeled the X axis, this is _micro_seconds since I measured from cfhistograms to avoid any network interference, so the differences are smaller than I originally implied (and may explain the throughput similarity since network latency would dominate.) Let's look at this statistically (as derived from the histogram data) instead. h4. Non-contended ||type||trunk||2893|| |Mean|9.0105|9.5486| |SD|7.5795|7.6594| |10th %|5|5| |25th %|6|7| |50th %|8|8| |75th %|10|10| |95th %|42|42| |99th %|103|103| h4. Contended ||type||trunk||2893|| |Mean|10.2212|14.9205| |SD|8.1631|11.7420| |10th %|6|8| |25th %|7|10| |50th %|8|12| |75th %|12|17| |95th %|42|72| |99th %|103|124| Non-contended is almost exactly the same in every way. Things begin to differ with a contended row, but nothing I would call twice as bad. was (Author: brandon.williams): Maybe a chart isn't the best way to look at this. First, let me note that I mislabeled the X axis, this is _micro_seconds since I measured from cfhistograms to avoid any network interference, so the differences are smaller than I originally implied (and may explain the throughput similarity since network latency would dominate.) Let's look at this statistically (as derived from the histogram data) instead. h4. Non-contended ||type||trunk||2893|| |Mean|9.0105|9.0113| |SD|7.5795|7.6782| |10th %|5|5| |25th %|6|7| |50th %|8|8| |75th %|10|10| |95th %|42|42| |99th %|103|103| h4. Contended ||type||trunk||2893|| |Mean|10.2212|10.2820| |SD|8.1631|12.6250| |10th %|6|8| |25th %|7|10| |50th %|8|12| |75th %|12|17| |95th %|42|72| |99th %|103|124| Non-contended is almost exactly the same in every way. Things begin to differ with a contended row, but nothing I would call twice as bad. > Add row-level isolation > ----------------------- > > Key: CASSANDRA-2893 > URL: https://issues.apache.org/jira/browse/CASSANDRA-2893 > Project: Cassandra > Issue Type: Improvement > Reporter: Jonathan Ellis > Assignee: Sylvain Lebresne > Priority: Minor > Fix For: 1.1 > > Attachments: 0001-Move-deletion-infos-into-ISortedColumns-v2.patch, > 0001-Move-deletion-infos-into-ISortedColumns.patch, > 0002-Make-memtable-use-CF.addAll-v2.patch, > 0002-Make-memtable-use-CF.addAll.patch, > 0003-Add-AtomicSortedColumn-and-snapTree-v2.patch, > 0003-Add-AtomicSortedColumn-and-snapTree.patch, latency-plain.svg, > latency.svg, snaptree-0.1-SNAPSHOT.jar > > > This could be done using an the atomic ConcurrentMap operations from the > Memtable and something like http://code.google.com/p/pcollections/ to replace > the ConcurrentSkipListMap in ThreadSafeSortedColumns. The trick is that > pcollections does not provide a SortedMap, so we probably need to write our > own. > Googling [persistent sortedmap] I found > http://code.google.com/p/actord/source/browse/trunk/actord/src/main/scala/ff/collection > (in scala) and http://clojure.org/data_structures#Data Structures-Maps. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira