1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
package grpc_prometheus
import (
prom "github.com/prometheus/client_golang/prometheus"
"golang.org/x/net/context"
"google.golang.org/grpc"
"google.golang.org/grpc/status"
)
// ServerMetrics represents a collection of metrics to be registered on a
// Prometheus metrics registry for a gRPC server.
type ServerMetrics struct {
serverStartedCounter *prom.CounterVec
serverHandledCounter *prom.CounterVec
serverStreamMsgReceived *prom.CounterVec
serverStreamMsgSent *prom.CounterVec
serverHandledHistogramEnabled bool
serverHandledHistogramOpts prom.HistogramOpts
serverHandledHistogram *prom.HistogramVec
}
// NewServerMetrics returns a ServerMetrics object. Use a new instance of
// ServerMetrics when not using the default Prometheus metrics registry, for
// example when wanting to control which metrics are added to a registry as
// opposed to automatically adding metrics via init functions.
func NewServerMetrics(counterOpts ...CounterOption) *ServerMetrics {
opts := counterOptions(counterOpts)
return &ServerMetrics{
serverStartedCounter: prom.NewCounterVec(
opts.apply(prom.CounterOpts{
Name: "grpc_server_started_total",
Help: "Total number of RPCs started on the server.",
}), []string{"grpc_type", "grpc_service", "grpc_method"}),
serverHandledCounter: prom.NewCounterVec(
opts.apply(prom.CounterOpts{
Name: "grpc_server_handled_total",
Help: "Total number of RPCs completed on the server, regardless of success or failure.",
}), []string{"grpc_type", "grpc_service", "grpc_method", "grpc_code"}),
serverStreamMsgReceived: prom.NewCounterVec(
opts.apply(prom.CounterOpts{
Name: "grpc_server_msg_received_total",
Help: "Total number of RPC stream messages received on the server.",
}), []string{"grpc_type", "grpc_service", "grpc_method"}),
serverStreamMsgSent: prom.NewCounterVec(
opts.apply(prom.CounterOpts{
Name: "grpc_server_msg_sent_total",
Help: "Total number of gRPC stream messages sent by the server.",
}), []string{"grpc_type", "grpc_service", "grpc_method"}),
serverHandledHistogramEnabled: false,
serverHandledHistogramOpts: prom.HistogramOpts{
Name: "grpc_server_handling_seconds",
Help: "Histogram of response latency (seconds) of gRPC that had been application-level handled by the server.",
Buckets: prom.DefBuckets,
},
serverHandledHistogram: nil,
}
}
// EnableHandlingTimeHistogram enables histograms being registered when
// registering the ServerMetrics on a Prometheus registry. Histograms can be
// expensive on Prometheus servers. It takes options to configure histogram
// options such as the defined buckets.
func (m *ServerMetrics) EnableHandlingTimeHistogram(opts ...HistogramOption) {
for _, o := range opts {
o(&m.serverHandledHistogramOpts)
}
if !m.serverHandledHistogramEnabled {
m.serverHandledHistogram = prom.NewHistogramVec(
m.serverHandledHistogramOpts,
[]string{"grpc_type", "grpc_service", "grpc_method"},
)
}
m.serverHandledHistogramEnabled = true
}
// Describe sends the super-set of all possible descriptors of metrics
// collected by this Collector to the provided channel and returns once
// the last descriptor has been sent.
func (m *ServerMetrics) Describe(ch chan<- *prom.Desc) {
m.serverStartedCounter.Describe(ch)
m.serverHandledCounter.Describe(ch)
m.serverStreamMsgReceived.Describe(ch)
m.serverStreamMsgSent.Describe(ch)
if m.serverHandledHistogramEnabled {
m.serverHandledHistogram.Describe(ch)
}
}
// Collect is called by the Prometheus registry when collecting
// metrics. The implementation sends each collected metric via the
// provided channel and returns once the last metric has been sent.
func (m *ServerMetrics) Collect(ch chan<- prom.Metric) {
m.serverStartedCounter.Collect(ch)
m.serverHandledCounter.Collect(ch)
m.serverStreamMsgReceived.Collect(ch)
m.serverStreamMsgSent.Collect(ch)
if m.serverHandledHistogramEnabled {
m.serverHandledHistogram.Collect(ch)
}
}
// UnaryServerInterceptor is a gRPC server-side interceptor that provides Prometheus monitoring for Unary RPCs.
func (m *ServerMetrics) UnaryServerInterceptor() func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
monitor := newServerReporter(m, Unary, info.FullMethod)
monitor.ReceivedMessage()
resp, err := handler(ctx, req)
st, _ := status.FromError(err)
monitor.Handled(st.Code())
if err == nil {
monitor.SentMessage()
}
return resp, err
}
}
// StreamServerInterceptor is a gRPC server-side interceptor that provides Prometheus monitoring for Streaming RPCs.
func (m *ServerMetrics) StreamServerInterceptor() func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
monitor := newServerReporter(m, streamRPCType(info), info.FullMethod)
err := handler(srv, &monitoredServerStream{ss, monitor})
st, _ := status.FromError(err)
monitor.Handled(st.Code())
return err
}
}
// InitializeMetrics initializes all metrics, with their appropriate null
// value, for all gRPC methods registered on a gRPC server. This is useful, to
// ensure that all metrics exist when collecting and querying.
func (m *ServerMetrics) InitializeMetrics(server *grpc.Server) {
serviceInfo := server.GetServiceInfo()
for serviceName, info := range serviceInfo {
for _, mInfo := range info.Methods {
preRegisterMethod(m, serviceName, &mInfo)
}
}
}
func streamRPCType(info *grpc.StreamServerInfo) grpcType {
if info.IsClientStream && !info.IsServerStream {
return ClientStream
} else if !info.IsClientStream && info.IsServerStream {
return ServerStream
}
return BidiStream
}
// monitoredStream wraps grpc.ServerStream allowing each Sent/Recv of message to increment counters.
type monitoredServerStream struct {
grpc.ServerStream
monitor *serverReporter
}
func (s *monitoredServerStream) SendMsg(m interface{}) error {
err := s.ServerStream.SendMsg(m)
if err == nil {
s.monitor.SentMessage()
}
return err
}
func (s *monitoredServerStream) RecvMsg(m interface{}) error {
err := s.ServerStream.RecvMsg(m)
if err == nil {
s.monitor.ReceivedMessage()
}
return err
}
// preRegisterMethod is invoked on Register of a Server, allowing all gRPC services labels to be pre-populated.
func preRegisterMethod(metrics *ServerMetrics, serviceName string, mInfo *grpc.MethodInfo) {
methodName := mInfo.Name
methodType := string(typeFromMethodInfo(mInfo))
// These are just references (no increments), as just referencing will create the labels but not set values.
metrics.serverStartedCounter.GetMetricWithLabelValues(methodType, serviceName, methodName)
metrics.serverStreamMsgReceived.GetMetricWithLabelValues(methodType, serviceName, methodName)
metrics.serverStreamMsgSent.GetMetricWithLabelValues(methodType, serviceName, methodName)
if metrics.serverHandledHistogramEnabled {
metrics.serverHandledHistogram.GetMetricWithLabelValues(methodType, serviceName, methodName)
}
for _, code := range allCodes {
metrics.serverHandledCounter.GetMetricWithLabelValues(methodType, serviceName, methodName, code.String())
}
}
|