1/* 2 * 3 * Copyright 2017 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19// Package keepalive defines configurable parameters for point-to-point 20// healthcheck. 21package keepalive 22 23import ( 24 "time" 25) 26 27// ClientParameters is used to set keepalive parameters on the client-side. 28// These configure how the client will actively probe to notice when a 29// connection is broken and send pings so intermediaries will be aware of the 30// liveness of the connection. Make sure these parameters are set in 31// coordination with the keepalive policy on the server, as incompatible 32// settings can result in closing of connection. 33type ClientParameters struct { 34 // After a duration of this time if the client doesn't see any activity it 35 // pings the server to see if the transport is still alive. 36 // If set below 10s, a minimum value of 10s will be used instead. 37 Time time.Duration // The current default value is infinity. 38 // After having pinged for keepalive check, the client waits for a duration 39 // of Timeout and if no activity is seen even after that the connection is 40 // closed. 41 Timeout time.Duration // The current default value is 20 seconds. 42 // If true, client sends keepalive pings even with no active RPCs. If false, 43 // when there are no active RPCs, Time and Timeout will be ignored and no 44 // keepalive pings will be sent. 45 PermitWithoutStream bool // false by default. 46} 47 48// ServerParameters is used to set keepalive and max-age parameters on the 49// server-side. 50type ServerParameters struct { 51 // MaxConnectionIdle is a duration for the amount of time after which an 52 // idle connection would be closed by sending a GoAway. Idleness duration is 53 // defined since the most recent time the number of outstanding RPCs became 54 // zero or the connection establishment. 55 MaxConnectionIdle time.Duration // The current default value is infinity. 56 // MaxConnectionAge is a duration for the maximum amount of time a 57 // connection may exist before it will be closed by sending a GoAway. A 58 // random jitter of +/-10% will be added to MaxConnectionAge to spread out 59 // connection storms. 60 MaxConnectionAge time.Duration // The current default value is infinity. 61 // MaxConnectionAgeGrace is an additive period after MaxConnectionAge after 62 // which the connection will be forcibly closed. 63 MaxConnectionAgeGrace time.Duration // The current default value is infinity. 64 // After a duration of this time if the server doesn't see any activity it 65 // pings the client to see if the transport is still alive. 66 // If set below 1s, a minimum value of 1s will be used instead. 67 Time time.Duration // The current default value is 2 hours. 68 // After having pinged for keepalive check, the server waits for a duration 69 // of Timeout and if no activity is seen even after that the connection is 70 // closed. 71 Timeout time.Duration // The current default value is 20 seconds. 72} 73 74// EnforcementPolicy is used to set keepalive enforcement policy on the 75// server-side. Server will close connection with a client that violates this 76// policy. 77type EnforcementPolicy struct { 78 // MinTime is the minimum amount of time a client should wait before sending 79 // a keepalive ping. 80 MinTime time.Duration // The current default value is 5 minutes. 81 // If true, server allows keepalive pings even when there are no active 82 // streams(RPCs). If false, and client sends ping when there are no active 83 // streams, server will send GOAWAY and close the connection. 84 PermitWithoutStream bool // false by default. 85} 86