Whooops On one of the nodes when running my tests I found an exception
java FileNotFoundException : file .... xxxx-Data.db not found at org.apache.cassandra.io.compress.CompressedThrottledReader.open(CompressedThrottledReader.java:52 also got another one coming from java.io.RandomAccessFile.open(native method) java.io.RandomAccessFile..<init> (RandomAccesFile.java:241) org.apache.cassandra.io.util.RandomAccessReader.<init>(RandomAccessReader.java:58) On Saturday, March 15, 2014 10:52 PM, Benedict Elliott Smith <belliottsm...@datastax.com> wrote: Post the server logs and traces of one of the lengthy queries? On 15 Mar 2014 20:49, "Batranut Bogdan" <batra...@yahoo.com> wrote: 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 <khangaon...@gmail.com> >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/ > >
