Why we apply delay between retry requests

Question

When we have a piece of code that often fails and must be retried. Then we use retry pattern.

try {
        //do request here
} catch (Exception e) {
        //wait for some millisecond and retry
        retry();
}

We normally delay for some millisecond before retry that request. I want to know that why we need some delay? What will happen if retry request did not wait and send request again.

What can happen is that you hammer the server with requests and potentially make the problem worse — JonK, Dec 01 '16 at 10:10
It is unlikely that a problem with the server is fixed in a few microseconds so an immediate retry is very unlikely to work and as JonK said would only contribute to problem. — Henry, Dec 01 '16 at 10:15
Ooo I see. Many thanks for adding this concept in my knowledge. — Muhammad Imran Tariq, Dec 01 '16 at 10:29
Before you hand-build lots of stuff like this, also check out libraries that have many ready-made primitives for retries and other resilience, eg https://github.com/jhalterman/failsafe [no personal involvement with this] — mountain traveller, Dec 01 '16 at 12:41
Possible duplicate of [What is the benefit of using exponential backoff?](http://stackoverflow.com/questions/28732327/what-is-the-benefit-of-using-exponential-backoff) — Paul Sweatte, Feb 21 '17 at 13:19

score 2 · Accepted Answer · answered Apr 13 '17 at 09:03

2

It is unlikely that a problem with the server is fixed in a few microseconds so an immediate retry is very unlikely to work and would only contribute to problem. So a delay between retry is best practice to follow.

answered Apr 13 '17 at 09:03

Muhammad Imran Tariq

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Why we apply delay between retry requests

1 Answers1