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.
21 package keepalive
22 23 import (
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.
33 type 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 //
38 // Note that gRPC servers have a default EnforcementPolicy.MinTime of 5
39 // minutes (which means the client shouldn't ping more frequently than every
40 // 5 minutes).
41 //
42 // Though not ideal, it's not a strong requirement for Time to be less than
43 // EnforcementPolicy.MinTime. Time will automatically double if the server
44 // disconnects due to its enforcement policy.
45 //
46 // For more details, see
47 // https://github.com/grpc/proposal/blob/master/A8-client-side-keepalive.md
48 Time time.Duration
49 // After having pinged for keepalive check, the client waits for a duration
50 // of Timeout and if no activity is seen even after that the connection is
51 // closed.
52 //
53 // If keepalive is enabled, and this value is not explicitly set, the default
54 // is 20 seconds.
55 Timeout time.Duration
56 // If true, client sends keepalive pings even with no active RPCs. If false,
57 // when there are no active RPCs, Time and Timeout will be ignored and no
58 // keepalive pings will be sent.
59 PermitWithoutStream bool
60 }
61 62 // ServerParameters is used to set keepalive and max-age parameters on the
63 // server-side.
64 type ServerParameters struct {
65 // MaxConnectionIdle is a duration for the amount of time after which an
66 // idle connection would be closed by sending a GoAway. Idleness duration is
67 // defined since the most recent time the number of outstanding RPCs became
68 // zero or the connection establishment.
69 MaxConnectionIdle time.Duration // The current default value is infinity.
70 // MaxConnectionAge is a duration for the maximum amount of time a
71 // connection may exist before it will be closed by sending a GoAway. A
72 // random jitter of +/-10% will be added to MaxConnectionAge to spread out
73 // connection storms.
74 MaxConnectionAge time.Duration // The current default value is infinity.
75 // MaxConnectionAgeGrace is an additive period after MaxConnectionAge after
76 // which the connection will be forcibly closed.
77 MaxConnectionAgeGrace time.Duration // The current default value is infinity.
78 // After a duration of this time if the server doesn't see any activity it
79 // pings the client to see if the transport is still alive.
80 // If set below 1s, a minimum value of 1s will be used instead.
81 Time time.Duration // The current default value is 2 hours.
82 // After having pinged for keepalive check, the server waits for a duration
83 // of Timeout and if no activity is seen even after that the connection is
84 // closed.
85 Timeout time.Duration // The current default value is 20 seconds.
86 }
87 88 // EnforcementPolicy is used to set keepalive enforcement policy on the
89 // server-side. Server will close connection with a client that violates this
90 // policy.
91 type EnforcementPolicy struct {
92 // MinTime is the minimum amount of time a client should wait before sending
93 // a keepalive ping.
94 MinTime time.Duration // The current default value is 5 minutes.
95 // If true, server allows keepalive pings even when there are no active
96 // streams(RPCs). If false, and client sends ping when there are no active
97 // streams, server will send GOAWAY and close the connection.
98 PermitWithoutStream bool // false by default.
99 }
100