Impala thread error

[#1]

Hi,

I am trying to run some impala queries through impala shell and every time it throws an error :

ERROR: Failed to create thread scanner-thread (finst:1d4df837xxx:f84fad02xxx, plan-node-id:1, thread-idx:28) in category fragment-execution: boost::thread_resource_error: Resource temporarily unavailable.

In cloudera manager Impala service seems ok and stable. Why this happens?

Thanks in advance.

[#2]

This error indicates that impalad daemon was not able to secure a processing thread on the node. Could be because the node is struggling under heavy load. 

What services are running in parallel with Impala on this host? What is the hardware configuration? What is the CPU utilization on the host?