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