1. A messaging system, comprising: a broker cluster including a plurality of brokers configured to relay messages from at least one publisher to at least one subscriber over one or more networked cluster connections in accordance with a predefined publish/subscribe model related policy; a test driver configured to receive instructions regarding errors to be simulated in association with one or more components in the messaging system; a simulator configured to simulate a network link and properties associated with the link; and processing resources including at least one processor and a memory configured to: coordinate with the test driver and the simulator to selectively generate errors in one or more components of the messaging system, post-deployment and while it is live, in accordance with the instructions, and determine whether the messaging system appropriately handled the errors selectively generated in response to the instructions.