Flush code didn't change between 0.7.0 and 0.7.2. There must be some other variable here. Memory pressure maybe?
On Sat, Feb 19, 2011 at 8:16 AM, Ivan Georgiev <yngw...@bk.ru> wrote: > Hi, > > I am testing 0.7.2 on a Windows 2003 x64 system(one node) and I am having > the following problem. > My insertion speed is relatively slow, so the memtables do not get full and > the actual flushing is triggered by memtable_flush_after_mins, this happens > on the hour mark. My problem with 0.7.2 is that when that happens, the cpu > spikes to 25% overall usage (x4 Xeon) and the operation takes anywhere from > 2 to 4 minutes, leaving the node not responding during that time. This has > forced to me to increase the rpc timeout option to beyond what i feel > comfortable with. > I have run multiple tests with 0.7.0 and 0.7.2 with the same dataset and the > results are consistent. During the same operation 0.7.0 takes about 10 > seconds to complete vs. 2 to 4 minutes for 0.7.2. I am attaching a log with > the timestamps from one such flushing of 0.7.2. Please let me know if there > is anything i can do to speed up and get results similar to 0.7.0. > > Regards: > Ivan > > This is the log of the operations which took most time during the flush > operation. Using 0.7.0, with the same number of operations the flushing > takes less than 10 seconds. > > INFO 01:36:44,906 Enqueuing flush of > Memtable-ArchiveFiles.6f776e65724944@1225856921(1619949 bytes, 34467 > operations) > INFO 01:37:47,375 Completed flushing > C:\Storage\data\Storage\ArchiveFiles.68617368-f-3-Data.db (5549187 bytes) > INFO 01:37:47,375 Writing Memtable-ArchiveFiles.6e616d65@978152661(1619949 > bytes, 34467 operations) > INFO 01:37:47,375 Enqueuing flush of > Memtable-ArchiveFiles.706172656e74466f6c6465724944@2097700961(1619949 bytes, > 34467 operations) > INFO 01:38:51,343 Completed flushing > C:\Storage\data\Storage\ArchiveFiles.6e616d65-f-3-Data.db (3820265 bytes) > INFO 01:38:51,343 Writing > Memtable-ArchiveFiles.6f776e65724944@1225856921(1619949 bytes, 34467 > operations) > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
