Hello, Yes for the first query the server can be slow but no matter what is should not take 10 seconds to get one key from a column family. I can see this happening if I have times like 20 ms for some queries and let's say 300 ms for uncached ones. But I have responses that take from 8 to 20 ms (420 out of 450 queries) and 30 response that take from 5 to 13 seconds. It is this HUGE difference that bothers me.
On Friday, March 14, 2014 9:18 PM, Manoj Khangaonkar <[email protected]> wrote: > > > >I have ~450 queries that are like this: SELECT * FROM table where key = 'some >string' and ts = some value; some value is close to present time. > > >The problem: > > >About 10 - 20 % of these queries take more than 5 seconds to execute, in fact, >the majority of those take around 10 seconds. >When investigating I saw that if I have a slow response and I redo the query >it will finish in 8 - 10 MILIseconds like the rest of the queries that I have. > > > Most likely for the first slow query, the server has to go looking in SSTables on disk. 2nd fast response is returned from memory. I am not sure how much data each node is managing. But try adding more nodes , so that each node is managing fewer keys. More nodes with recommended heap size of 8G is better than fewer nodes with bigger heap size. regards -- http://khangaonkar.blogspot.com/
