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There already is a similar feature - Partition Awareness. When enabled, the client calls exactly the primary node to update cache by key.
To achieve Service Awareness we should:
1) Bring a new feature to the thin client protocol.
2) Require and activate with the Partition Awareness flag enabled. It raises proper cluster connections.
3) Obtain service topology with a dedicated request by the client and provide it to the service proxies.
4) Initiate the topology update with: first service invocation, cluster topology change, some timeout (only if service is invoked).
Minimal client protocol version | 1.7.0 |
The new protocol feature | SERVICE_TOPOLOGY = 16 |
One new client operation is required:
Name | Code |
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OP_SERVICE_GET_TOPOLOGY | 90247003 |
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- Some delay of the topology obtaining. The invocation redirects are still possible when service migrates.
- No sign of service cancel/deploy on the client side. We have to update by a timeout too.
- The topology is probably kept by client while it exists even if the service proxy is not in use any more or if service was canceled.
https://lists.apache.org/thread/vd0wnwxrg89245kv1nzolfb82j1l7z0t
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