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@ -89,26 +89,28 @@ servers. |
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client config. |
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2. The gRPC client connects to a gRPC Server. |
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1. If the name resolution has hinted that the endpoint is a load balancer, |
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the client will attempt to open a stream to the load balancer service. The |
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server may respond in only one of the following ways. |
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the client's gRPC LB policy will attempt to open a stream to the load |
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balancer service. The server may respond in only one of the following |
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ways. |
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1. `status::UNIMPLEMENTED`. There is no loadbalancing in use. The client |
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call will fail. |
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1. "I am a Load Balancer and here is the server list." (Goto Step 4.) |
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1. "Please contact Load Balancer X" (See Step 3.) The client will close |
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2. "I am a Load Balancer and here is the server list." (Goto Step 4.) |
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3. "Please contact Load Balancer X" (See Step 3.) The client will close |
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this connection and cancel the stream. |
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1. If the server fails to respond, the client will wait for some timeout |
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4. If the server fails to respond, the client will wait for some timeout |
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and then re-resolve the name (process to Step 1 above). |
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1. If the name resolution has not hinted that the endpoint is a load |
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2. If the name resolution has not hinted that the endpoint is a load |
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balancer, the client connects directly to the service it wants to talk to. |
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3. The gRPC client opens a separate connection to the Load Balancer. If this |
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fails, it will go back to step 1 and try another address. |
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3. The gRPC client's gRPC LB policy opens a separate connection to the Load |
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Balancer. If this fails, it will go back to step 1 and try another address. |
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1. During channel initialization to the Load Balancer, the client will |
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attempt to open a stream to the Load Balancer service. |
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1. The load balancer will return a server list to the gRPC client. |
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Optional: The load balancer will also open channels to the gRPC servers if |
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load reporting is needed. |
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2. The Load Balancer will return a server list to the gRPC client. If the |
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server list is empty, the call will wait until a non-empty one is |
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received. Optional: The Load Balancer will also open channels to the gRPC |
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servers if load reporting is needed. |
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4. The gRPC client will send RPCs to the gRPC servers contained in the server |
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list from the load balancer. |
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list from the Load Balancer. |
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5. Optional: The gRPC servers may periodically report load to the Load Balancer. |
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## Client |
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