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Compatibility, Deprecation, and Migration Plan

Server-Client Version Bump

This change requires Only client side upgrade is required as long as the Kafka broker version >= 0.9, where broker will react with a rebalance when a normal consumer changes the encoded metadata.

Client application needs to update to the latest version in order to utilize this change.

Switching Protocol Type

As we have mentioned above, a new protocol type shall be created. To ensure smooth transition, we need to make sure the existing job doesn't fail. So we need to explicitly set The workflow for upgrading is like below:

• Set the `stream.rebalancing.mode` to `upgrading`, where we

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• will set the protocol type remaining to "consumer".
• Rolling restart the stream application, the change should be safe because we are not changing protocol type anyway.

In long term we are proposing a more smooth upgrade approach than the current one. However it requires broker upgrade which may not be trivial effort for the end user as protocolType for existing stream jobs. Otherwise the job upgrade would fail due to incompatible protocol type.

FAQ

Why do we call stream workers?

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