Using all the CPU cores by NDBD and MySQL We are running MariaDB which is a fork of MySQL with NDB cluster engine. 
The cluster includes one mysql node and two ndb data nodes. While benchmarking the cluster, we are trying to make a bottleneck of CPU and the mysql nodes has 8 cores in total. But mysqld process uses only one to two cores and does not utilizing more than 2 cores.
We tried increasing threads and warehouses but that did not help in utilizing all the CPU cores. Is there a way to make this possible. What system variables should I focus on to increase??? 

Any thoughts or suggestions are appreciated.
Solution is rather simple: Run mysqld multiple times on the same DB Server !!!.

Assign each mysqld to run on a different port.

The OS will spread the multple mysqld processes across the cores.

UPDATE

You may have to jerry rig some port forwarding using mysql-proxy

Assuming 10.240.35.180 is the SQL node


startup mysql on port 3307 in the SQL node
startup mysql on port 3308 in the SQL node
startup mysql on port 3309 in the SQL node
startup mysql on port 3310 in the SQL node


In the mgnt node, set up 4 instances of mysql-proxy


mysql-proxy 10.1.1.6 to 10.240.35.180 port 3307
mysql-proxy 10.1.1.7 to 10.240.35.180 port 3308
mysql-proxy 10.1.1.8 to 10.240.35.180 port 3309
mysql-proxy 10.1.1.9 to 10.240.35.180 port 3310


Now place IPs 10.1.1.6 - 10.1.1.9 in config.ini and startup mysql cluster. This sounds like a very major stretch, but it's your only shot at getting mysqld running across multiple cores.

BTW : back on August 10, 2011, someone asked a similar question in ServerFault and gave a detailed explanantion from the MySQL Cluster Team.

Give it a Try !!!