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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 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).
One new client operation is required:
Name | Code |
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OP_SERVICE_GET_TOPOLOGY | 9024 |
Request | |
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String | Service name |
Response | |
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int | Number of the following nodes UUIDs |
UUID * count | UUID of node with at least one service instance |
- 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 is not in use any more.
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