| // Copyright 2016, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| syntax = "proto3"; |
| |
| package grpc.lb.v1; |
| |
| message Duration { |
| |
| // Signed seconds of the span of time. Must be from -315,576,000,000 |
| // to +315,576,000,000 inclusive. |
| int64 seconds = 1; |
| |
| // Signed fractions of a second at nanosecond resolution of the span |
| // of time. Durations less than one second are represented with a 0 |
| // `seconds` field and a positive or negative `nanos` field. For durations |
| // of one second or more, a non-zero value for the `nanos` field must be |
| // of the same sign as the `seconds` field. Must be from -999,999,999 |
| // to +999,999,999 inclusive. |
| int32 nanos = 2; |
| } |
| |
| service LoadBalancer { |
| // Bidirectional rpc to get a list of servers. |
| rpc BalanceLoad(stream LoadBalanceRequest) |
| returns (stream LoadBalanceResponse); |
| } |
| |
| message LoadBalanceRequest { |
| oneof load_balance_request_type { |
| // This message should be sent on the first request to the load balancer. |
| InitialLoadBalanceRequest initial_request = 1; |
| |
| // The client stats should be periodically reported to the load balancer |
| // based on the duration defined in the InitialLoadBalanceResponse. |
| ClientStats client_stats = 2; |
| } |
| } |
| |
| message InitialLoadBalanceRequest { |
| // Name of load balanced service (IE, service.grpc.gslb.google.com) |
| string name = 1; |
| } |
| |
| // Contains client level statistics that are useful to load balancing. Each |
| // count should be reset to zero after reporting the stats. |
| message ClientStats { |
| // The total number of requests sent by the client since the last report. |
| int64 total_requests = 1; |
| |
| // The number of client rpc errors since the last report. |
| int64 client_rpc_errors = 2; |
| |
| // The number of dropped requests since the last report. |
| int64 dropped_requests = 3; |
| } |
| |
| message LoadBalanceResponse { |
| oneof load_balance_response_type { |
| // This message should be sent on the first response to the client. |
| InitialLoadBalanceResponse initial_response = 1; |
| |
| // Contains the list of servers selected by the load balancer. The client |
| // should send requests to these servers in the specified order. |
| ServerList server_list = 2; |
| } |
| } |
| |
| message InitialLoadBalanceResponse { |
| oneof initial_response_type { |
| // TODO(zhangkun83): ClientConfig not yet defined |
| //ClientConfig client_config = 1; |
| |
| // This is an application layer redirect that indicates the client should |
| // use the specified server for load balancing. When this field is set in |
| // the response, the client should open a separate connection to the |
| // load_balancer_delegate and call the BalanceLoad method. |
| string load_balancer_delegate = 2; |
| } |
| |
| // This interval defines how often the client should send the client stats |
| // to the load balancer. Stats should only be reported when the duration is |
| // positive. |
| Duration client_stats_report_interval = 3; |
| } |
| |
| message ServerList { |
| // Contains a list of servers selected by the load balancer. The list will |
| // be updated when server resolutions change or as needed to balance load |
| // across more servers. The client should consume the server list in order |
| // unless instructed otherwise via the client_config. |
| repeated Server servers = 1; |
| |
| // Indicates the amount of time that the client should consider this server |
| // list as valid. It may be considered stale after waiting this interval of |
| // time after receiving the list. If the interval is not positive, the |
| // client can assume the list is valid until the next list is received. |
| Duration expiration_interval = 3; |
| } |
| |
| message Server { |
| // A resolved address and port for the server. The IP address string may |
| // either be an IPv4 or IPv6 address. |
| string ip_address = 1; |
| int32 port = 2; |
| |
| // An opaque token that is passed from the client to the server in metadata. |
| // The server may expect this token to indicate that the request from the |
| // client was load balanced. |
| string load_balance_token = 3; |
| |
| // Indicates whether this particular request should be dropped by the client |
| // when this server is chosen from the list. |
| bool drop_request = 4; |
| } |