API Retry Strategy
OUTSCALE SDKs for our APIs include built-in support for automatic retries with exponential backoff when encountering transient HTTP errors.
Supported SDKs
Retry logic is currently implemented in the following SDKs:
| SDK | Versions |
|---|---|
Python |
0.35.0 and up |
JavaScript/TypeScript |
All |
Rust |
1.18.0 and up |
Go |
3.0.0-alpha.1 and up |
General Information
The SDK automatically retries requests that fail with the following HTTP status codes:
-
HTTP 429 Too Many Requests-
Code 24 - ErrorOperationThrottledPerAccount: Request rate exceeded. -
Code 25 - ErrorOperationThrottledPerCall: Request rate exceeded.
-
-
HTTP 500 Internal Server Error – Temporary server issue. -
HTTP 503 Service Unavailable – ErrorOperationThrottledWholePlatform: Request rate exceeded.
|
For more information, see the Error Codes Reference page. |
The retry mechanism is based on the behavior of urllib3.util.Retry. By default, it is configured as follows:
-
Maximum retries: 3
-
Backoff factor: 1
-
Backoff jitter: 3 s
Exponential Backoff
Exponential backoff is a strategy used to manage retries after the API returns a limit code.
The delay between each retry attempt increases exponentially. The rate limit is configured per API call per OUTSCALE account. To help mitigate concurrency issues when using a multithreaded program making API calls, jitter is added to the strategy.
It is calculated as follows:
{backoff factor} * (2 ** ({number of previous retries}))Example of backoff and jitter settings:
| Retry Attempt | Wait Time (in seconds) |
|---|---|
1st retry |
Between 0 s and 3 s |
2nd retry |
Between 2 s and 5 s |
3rd retry |
Between 4 s and 7 s |
Retry Customization
The retry behavior can be customized. You need to add or modify the following parameters:
-
max_retries: The maximum number of retry attempts before the request fails. -
retry_backoff_factor: The multiplier for the exponential backoff delay. -
retry_backoff_jitter: A value added to the delay to avoid all retries happening at the same time in multithreaded scenarios.
Customize the Python SDK
Example of customization for osc-sdk-python file:
"eu2": {
"access_key": "XXXX",
"region_name": "eu-west-2",
"secret_key": "XXXX",
"max_retries": 3,
"retry_backoff_factor": 1,
"retry_backoff_jitter": 3
}