Storm has a variety of configurations for tweaking the behavior of nimbus, supervisors, and running topologies. Some configurations are system configurations and cannot be modified on a topology by topology basis, whereas other configurations can be modified per topology.
Every configuration has a default value defined in defaults.yaml in the Storm codebase. You can override these configurations by defining a storm.yaml in the classpath of Nimbus and the supervisors. Finally, you can define a topology-specific configuration that you submit along with your topology when using StormSubmitter. However, the topology-specific configuration can only override configs prefixed with "TOPOLOGY".
Storm 0.7.0 and onwards lets you override configuration on a per-bolt/per-spout basis. The only configurations that can be overriden this way are:
The Java API lets you specify component specific configurations in two ways:
getComponentConfigurationin any spout or bolt and return the component-specific configuration map.
TopologyBuilderreturn an object with methods
addConfigurationsthat can be used to override the configurations for the component.
The preference order for configuration values is defaults.yaml < storm.yaml < topology specific configuration < internal component specific configuration < external component specific configuration.