Cassandra dead but pid file exists

Question

I have novice to cassandra and tried my hands to install cassandra-2.1.2 on centos 7.0. After complete installation execute cqlsh command and created few keyspace(s) and column

Answer 1

Check if you have enough memory to start cassandra service with this command:

cat /proc/meminfo

I was running Hortonworks VM with Virtualbox, and I had a lot of Hadoop components started which needed a lot of memory, so for me the solution was to stop unnecessary Hadoop components and add some extra memory to the virtual machine.