# Implementing Exponential Back-Off

Exponential back-off is the process of a client periodically retrying a failed request over an increasing amount of time. ***It is a standard error handling strategy for network applications.*** Besides being “required”, using exponential back-off increases the efficiency of bandwidth usage, reduces the number of requests required to get a successful response and maximizes the throughput of requests in concurrent environments. 

The flow of implementing a simple exponential back-off is as follows:

1. Make a request to the API
2. Receive the response, check for error that ***has a retry-able error code (such as 503)***
3. Wait `1s + random_number_milliseconds` seconds
4. Retry request
5. Receive the response, check for error that ***has a retry-able error code (such as 503)***
6. Wait `2s + random_number_milliseconds` seconds
7. Retry request
8. Receive the response, check for error that ***has a retry-able error code (such as 503)***
9. Wait `4s + random_number_milliseconds` seconds
10. Retry request
11. Receive the response, check for error that ***has a retry-able error code (such as 503)***
12. Wait `8s + random_number_milliseconds` seconds
13. Retry request
14. Receive the response, check for error that ***has a retry-able error code (such as 503)***
15. Wait `16s + random_number_milliseconds` seconds
16. Retry request
17. If you still get an error, stop and log the error

{% hint style="info" %}
Note: random\_number\_milliseconds MUST be redefined after each “Wait” 
{% endhint %}

In the above flow, `random_number_milliseconds` is a random number of milliseconds less than or equal to 1000. This is necessary to avoid certain lock errors in some concurrent implementations. 

{% hint style="info" %}
Note: the wait is always (2^n) + random\_number\_milliseconds, where n is a monotonically increasing integer initially defined as 0. N is incremented by 1 for each iteration (each request)
{% endhint %}

The algorithm is set to terminate when n == 5. This ceiling is in place to prevent clients from retrying infinitely, and results in a total delay of 32 seconds before a deemed “unrecoverable error.”


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.zaui.com/io/getting-started/getting-started/implementing-exponential-back-off.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.