Spring / Spring Retry Interview Questions
How does the CompositeRetryPolicy work in Spring Retry?
CompositeRetryPolicy combines multiple RetryPolicy instances into one. It supports two composition modes: optimistic and pessimistic. This is useful when you need retry behavior that satisfies multiple independent conditions simultaneously.
Optimistic mode (default): A retry is allowed if any of the composed policies permit it. This is a logical OR across policies.
Pessimistic mode: A retry is allowed only if all of the composed policies permit it. This is a logical AND across policies.
SimpleRetryPolicy byCount = new SimpleRetryPolicy(5); TimeoutRetryPolicy byTime = new TimeoutRetryPolicy(); byTime.setTimeout(10000); // max 10 seconds total CompositeRetryPolicy composite = new CompositeRetryPolicy(); composite.setPolicies(new RetryPolicy[]{ byCount, byTime }); composite.setOptimistic(false); // pessimistic: both must agree RetryTemplate template = new RetryTemplate(); template.setRetryPolicy(composite);
In this example (pessimistic), both the count limit (5 attempts) and the time limit (10 seconds) must permit the retry. The retry stops when either limit is reached first — whichever comes first wins. This is a clean way to add a time-bound safety net on top of a count-based policy for long-running retries.
More Related questions...
