Announcement: Enabling OkHttp's retryOnConnectionFailure by default

What's changing

An upcoming release of the AWS SDK for Kotlin will enable OkHttp’s retryOnConnectionFailure option by default.

When retryOnConnectionFailure is enabled, clients will silently recover from the following problems:

• Unreachable IP addresses. If the URL's host has multiple IP addresses, failure to reach any individual IP address doesn't fail the overall request. This can increase availability of multi-homed services.
• Stale pooled connections. The connection pool reuses sockets to decrease request latency, but these connections will occasionally time out.
• Unreachable proxy servers. A ProxySelector can be used to attempt multiple proxy servers in sequence, eventually falling back to a direct connection.

The SDK is already set up to recover from various transient issues, and enabling this option expands this coverage even further. While this change is not necessarily breaking, increased attempts at error recovery may affect your application’s call patterns or increase resource usage.

How to migrate

The retryOnConnectionFailure configuration is now enabled by default, so all you have to do is upgrade your aws-sdk-kotlin and smithy-kotlin dependencies to v1.6.0 or later.

If you encounter any issues with this new configuration, you can disable it by overriding the default HTTP configuration. For example:

DynamoDbClient {
    httpClient(OkHttpEngine) {
        retryOnConnectionFailure = false
    }
}.use { ddb ->
    // Perform some actions with Amazon DynamoDB.
}

For more details on HTTP configuration, see our developer guide.

Release date

This feature will ship with the v1.6.0 release planned for no earlier than 1/15/2026.

Feedback

If you have any questions concerning this change, please feel free to engage with us in this discussion. If you encounter a bug with these changes, please file an issue.