cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Batranut Bogdan <>
Subject 2 Cassandra nodes slow
Date Tue, 13 Jan 2015 10:01:43 GMT
I have a cluster of 6 C* nodes. All machines have the same hardware. I have noticed in opscenter
that when I start reading a lot from the cluster 2 nodes have read latencies, but the rest
do not have such high values. The replication factor for the keyspace is 3. Also those 2 nodes
have latencies when measuring the CF Local Read Latency so I know that the reads on the main
col family are slow on these 2 nodes. Partitioning is good since in the column family there
are a few million possible values.Another thing is that I have stopped these 2 nodes and ran
a few selections for 6000 rows .... those were executed in about 15 seconds. I have changed
the keys so that I avoid caching as much as possible.Also I have done the same test when running
with all nodes and the execution of the selection was abou 22 seconds....
Any ideeas? 
I am thinking on rebuilding the data on the nodes... Stop the node , delete the data folder
and restart... but I don't know the consequences....
View raw message