You don't mention disks and RAM, but I would assume that the additional data meant that you could now cache a lower percentage and that you have to seek on disk more often.
-Tupshin On Feb 10, 2014 4:14 PM, "Jiaan Zeng" <l.alle...@gmail.com> wrote: > Hi All, > > I am using Cassandra 1.2.4. I wonder if update operation has > *permanent* impacts on read operation. Below is the scenario. > > Previously, a read only workload runs against one column family and > has 4000 qps. Later, a read-update mixed workload runs against the > same column family. After that, the read only workload runs again but > it could not get 4000 qps, only get 3500 qps. After a manual major > compaction is issued through command line, the read only workload gets > 3600 qps which seems to tell major compaction does not help much. > > Did anyone have similar experiences? Any idea why this is happening? > Thanks. > > -- > Regards, > Jiaan >
