vendor/google.golang.org/grpc/grpclb/grpc_lb_v1/grpclb.proto

   1 // Copyright 2016 gRPC authors.
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 syntax = "proto3";
  16
  17 package grpc.lb.v1;
  18
  19 message Duration {
  20   // Signed seconds of the span of time. Must be from -315,576,000,000
  21   // to +315,576,000,000 inclusive.
  22   int64 seconds = 1;
  23
  24   // Signed fractions of a second at nanosecond resolution of the span
  25   // of time. Durations less than one second are represented with a 0
  26   // `seconds` field and a positive or negative `nanos` field. For durations
  27   // of one second or more, a non-zero value for the `nanos` field must be
  28   // of the same sign as the `seconds` field. Must be from -999,999,999
  29   // to +999,999,999 inclusive.
  30   int32 nanos = 2;
  31 }
  32
  33 message Timestamp {
  34
  35   // Represents seconds of UTC time since Unix epoch
  36   // 1970-01-01T00:00:00Z. Must be from 0001-01-01T00:00:00Z to
  37   // 9999-12-31T23:59:59Z inclusive.
  38   int64 seconds = 1;
  39
  40   // Non-negative fractions of a second at nanosecond resolution. Negative
  41   // second values with fractions must still have non-negative nanos values
  42   // that count forward in time. Must be from 0 to 999,999,999
  43   // inclusive.
  44   int32 nanos = 2;
  45 }
  46
  47 service LoadBalancer {
  48   // Bidirectional rpc to get a list of servers.
  49   rpc BalanceLoad(stream LoadBalanceRequest)
  50       returns (stream LoadBalanceResponse);
  51 }
  52
  53 message LoadBalanceRequest {
  54   oneof load_balance_request_type {
  55     // This message should be sent on the first request to the load balancer.
  56     InitialLoadBalanceRequest initial_request = 1;
  57
  58     // The client stats should be periodically reported to the load balancer
  59     // based on the duration defined in the InitialLoadBalanceResponse.
  60     ClientStats client_stats = 2;
  61   }
  62 }
  63
  64 message InitialLoadBalanceRequest {
  65   // Name of load balanced service (IE, balancer.service.com)
  66   // length should be less than 256 bytes.
  67   string name = 1;
  68 }
  69
  70 // Contains client level statistics that are useful to load balancing. Each
  71 // count except the timestamp should be reset to zero after reporting the stats.
  72 message ClientStats {
  73   // The timestamp of generating the report.
  74   Timestamp timestamp = 1;
  75
  76   // The total number of RPCs that started.
  77   int64 num_calls_started = 2;
  78
  79   // The total number of RPCs that finished.
  80   int64 num_calls_finished = 3;
  81
  82   // The total number of RPCs that were dropped by the client because of rate
  83   // limiting.
  84   int64 num_calls_finished_with_drop_for_rate_limiting = 4;
  85
  86   // The total number of RPCs that were dropped by the client because of load
  87   // balancing.
  88   int64 num_calls_finished_with_drop_for_load_balancing = 5;
  89
  90   // The total number of RPCs that failed to reach a server except dropped RPCs.
  91   int64 num_calls_finished_with_client_failed_to_send = 6;
  92
  93   // The total number of RPCs that finished and are known to have been received
  94   // by a server.
  95   int64 num_calls_finished_known_received = 7;
  96 }
  97
  98 message LoadBalanceResponse {
  99   oneof load_balance_response_type {
 100     // This message should be sent on the first response to the client.
 101     InitialLoadBalanceResponse initial_response = 1;
 102
 103     // Contains the list of servers selected by the load balancer. The client
 104     // should send requests to these servers in the specified order.
 105     ServerList server_list = 2;
 106   }
 107 }
 108
 109 message InitialLoadBalanceResponse {
 110   // This is an application layer redirect that indicates the client should use
 111   // the specified server for load balancing. When this field is non-empty in
 112   // the response, the client should open a separate connection to the
 113   // load_balancer_delegate and call the BalanceLoad method. Its length should
 114   // be less than 64 bytes.
 115   string load_balancer_delegate = 1;
 116
 117   // This interval defines how often the client should send the client stats
 118   // to the load balancer. Stats should only be reported when the duration is
 119   // positive.
 120   Duration client_stats_report_interval = 2;
 121 }
 122
 123 message ServerList {
 124   // Contains a list of servers selected by the load balancer. The list will
 125   // be updated when server resolutions change or as needed to balance load
 126   // across more servers. The client should consume the server list in order
 127   // unless instructed otherwise via the client_config.
 128   repeated Server servers = 1;
 129
 130   // Indicates the amount of time that the client should consider this server
 131   // list as valid. It may be considered stale after waiting this interval of
 132   // time after receiving the list. If the interval is not positive, the
 133   // client can assume the list is valid until the next list is received.
 134   Duration expiration_interval = 3;
 135 }
 136
 137 // Contains server information. When none of the [drop_for_*] fields are true,
 138 // use the other fields. When drop_for_rate_limiting is true, ignore all other
 139 // fields. Use drop_for_load_balancing only when it is true and
 140 // drop_for_rate_limiting is false.
 141 message Server {
 142   // A resolved address for the server, serialized in network-byte-order. It may
 143   // either be an IPv4 or IPv6 address.
 144   bytes ip_address = 1;
 145
 146   // A resolved port number for the server.
 147   int32 port = 2;
 148
 149   // An opaque but printable token given to the frontend for each pick. All
 150   // frontend requests for that pick must include the token in its initial
 151   // metadata. The token is used by the backend to verify the request and to
 152   // allow the backend to report load to the gRPC LB system.
 153   //
 154   // Its length is variable but less than 50 bytes.
 155   string load_balance_token = 3;
 156
 157   // Indicates whether this particular request should be dropped by the client
 158   // for rate limiting.
 159   bool drop_for_rate_limiting = 4;
 160
 161   // Indicates whether this particular request should be dropped by the client
 162   // for load balancing.
 163   bool drop_for_load_balancing = 5;
 164 }