Some important info to look in Gangalia UI in CPU, memory and server load charts to spot the problem:

CPU chart :

• User %
• Idle %

High percentage of user % indicates heavy CPU usage in the cluster.

Memory chart :

• Use %
• Free %
• Swap %

If you see purple line over red line in memory chart then it indicates memory swapping and also highlighting high memory usage.

Server Load Distribution Chart:

Absence of red squares indicates balanced load on the cluster. Presence of red squares means there is hot spot where load is more.