Retry Pattern Vs fall back pattern in rest client

Question

We have multiple resources exposed as REST service and running in to design argument whether client needs to implement re-try logic if service in unavailable due to network and/or application level failures. Is it worth it? One group argues, if service is unavailable then there is no point of re-trying but other group argues there may be network busy issues and re-try could help. There are no statistics to defend either arguments at this time. How about implementing a fall back URL (a replica of original http resource) and use fall back service during failures.

Any suggestions based on your prior experience?

Answer 1

Keep in mind that when a service request is failing, it can be due to network overload or service degradation. In several cases the best option is to just fail immediately. Regarding using a fall back URL, it probably will not solve your problem, since it could keep network under high load.

Suggestion is to take a look in patterns such as:

• Backpressure: http://mechanical-sympathy.blogspot.com.br/2012/05/apply-back-pressure-when-overloaded.html , http://engineering.voxer.com/2013/09/16/backpressure-in-nodejs/
• Circuit breaker, Load Shedding: http://martinfowler.com/bliki/CircuitBreaker.html , http://techblog.netflix.com/2012/02/fault-tolerance-in-high-volume.html
• Bulkhead pattern: http://skife.org/architecture/fault-tolerance/2009/12/31/bulkheads.html