Linking back to this question: Why not enable virtual node in an Hadoop node?
I'm running a mixed 3 node cluster with 2 cassandra and 1 analytics nodes and disabled the virtual nodes by generating 3 tokens with the utility given by DataStax enterprise. But when I run 'nodetool status' command, I still see 256 tokens with each node and when a mapreduce job is created, it creates 257 mappers and takes a very long time to execute a query with small data. So my specific questions are:
Is virtual node setting still not disabled? How can I verify if its disabled?
If its disabled then why 257 mappers are still created for each job? Is there a different configuration for that?
Thanks much for any help!!
1) It's not disabled. You can tell because it still says 256 tokens in nodetool status.
To disable vnodes you need to make sure that you change the num_tokens variable in the cassandra.yamnl
# If you already have a cluster with 1 token per node, and wish to migrate to
# multiple tokens per node, see http://wiki.apache.org/cassandra/Operations
# num_tokens: 256 << Make sure this line is commented out
# initial_token allows you to specify tokens manually. While you can use it with
# vnodes (num_tokens > 1, above) -- in which case you should provide a
# comma-separated list -- it's primarily used when adding nodes to legacy clusters
# that do not have vnodes enabled.
initial_token: << Your generated token goes here