• Contents
• Flow Chart
• 1. Construct a HystrixCommand or HystrixObservableCommand Object
• 2. Execute the Command
• 3. Is the Response Cached?
• 4. Is the Circuit Open?
• 5. Is the Thread Pool/Queue/Semaphore Full?
• 6. HystrixObservableCommand.construct() or HystrixCommand.run()
• 7. Calculate Circuit Health
• 8. Get the Fallback
• 9. Return the Successful Response
• Sequence Diagram
• Circuit Breaker
• Isolation
• Threads & Thread Pools
• Benefits of Thread Pools
• Drawbacks of Thread Pools
• Cost of Threads
• Semaphores
• Request Collapsing
• Sequence Diagram
• Why Use Request Collapsing?
• Global Context (Across All Tomcat Threads)
• User Request Context (Single Tomcat Thread)
• Object Modeling and Code Complexity
• What Is the Cost of Request Collapsing?
• Collapser Flow
• Request Caching