-
Notifications
You must be signed in to change notification settings - Fork 0
/
loadbalancing.go
187 lines (164 loc) · 4.71 KB
/
loadbalancing.go
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
186
187
package sensu
import (
"context"
"fmt"
"math/rand"
"net/http"
"time"
"github.com/sensu/uchiwa/uchiwa/logger"
)
// These are the methods directly used by the public methods of the sensu
// package in order to handle the failover and load balancing between the APIs of a datacenter
func (s *Sensu) delete(endpoint string) error {
var err error
apis, err := s.healthyAPIs()
if err != nil {
return err
}
shuffledRange := shuffle(makeRange(len(apis)))
for _, i := range shuffledRange {
logger.Debugf("DELETE %s/%s (%s)", s.APIs[i].URL, endpoint, s.Name)
res, err := apis[i].delete(endpoint)
if err == nil || res.StatusCode < 500 {
return nil
}
s.APIs[i].Healthy = false
logger.Debugf("DELETE %s/%s (%s) returned: %v", s.APIs[i].URL, endpoint, s.Name, err)
}
return err
}
func (s *Sensu) getBytes(endpoint string) ([]byte, *http.Response, error) {
var bytes []byte
var err error
var res *http.Response
apis, err := s.healthyAPIs()
if err != nil {
return nil, nil, err
}
shuffledRange := shuffle(makeRange(len(apis)))
for _, i := range shuffledRange {
bytes, res, err = s.getBytesFromAPI(apis[i], endpoint)
if err == nil {
return bytes, res, nil
}
}
return nil, nil, err
}
func (s *Sensu) getBytesFromAPI(api *API, endpoint string) ([]byte, *http.Response, error) {
logger.Debugf("GET %s/%s (%s)", api.URL, endpoint, s.Name)
bytes, res, err := api.getBytes(endpoint)
if res == nil || res.StatusCode >= 500 {
api.Healthy = false
} else {
api.Healthy = true
}
if err == nil && res.StatusCode < 400 {
return bytes, res, err
}
logger.Debugf("GET %s/%s (%s) returned: %v", api.URL, endpoint, s.Name, err)
return bytes, res, err
}
func (s *Sensu) getSlice(ctx context.Context, endpoint string, limit int) ([]interface{}, error) {
var err error
var slice []interface{}
var res *http.Response
apis, err := s.healthyAPIs()
if err != nil {
return nil, err
}
shuffledRange := shuffle(makeRange(len(apis)))
for _, i := range shuffledRange {
logger.Debugf("GET %s/%s (%s)", s.APIs[i].URL, endpoint, s.Name)
slice, res, err = apis[i].getSlice(ctx, endpoint, limit)
if err == nil || res != nil && res.StatusCode >= 400 && res.StatusCode < 500 {
return slice, err
}
s.APIs[i].Healthy = false
logger.Debugf("GET %s/%s (%s) returned: %v", s.APIs[i].URL, endpoint, s.Name, err)
}
return nil, err
}
func (s *Sensu) getMap(endpoint string) (map[string]interface{}, error) {
var err error
var m map[string]interface{}
var res *http.Response
apis, err := s.healthyAPIs()
if err != nil {
return nil, err
}
shuffledRange := shuffle(makeRange(len(apis)))
for _, i := range shuffledRange {
logger.Debugf("GET %s/%s (%s)", apis[i].URL, endpoint, s.Name)
m, res, err = apis[i].getMap(endpoint)
if res == nil || res.StatusCode >= 500 {
apis[i].Healthy = false
} else {
apis[i].Healthy = true
}
if err == nil && res.StatusCode < 400 {
return m, err
}
logger.Debugf("GET %s/%s (%s) returned: %v", apis[i].URL, endpoint, s.Name, err)
}
return nil, err
}
func (s *Sensu) getMapFromAPI(api *API, endpoint string) (map[string]interface{}, error) {
m, res, err := api.getMap(endpoint)
if err != nil || res != nil && res.StatusCode >= 500 {
api.Healthy = false
}
return m, err
}
func (s *Sensu) postPayload(endpoint string, payload string) (map[string]interface{}, error) {
var err error
var m map[string]interface{}
apis, err := s.healthyAPIs()
if err != nil {
return nil, err
}
shuffledRange := shuffle(makeRange(len(apis)))
for _, i := range shuffledRange {
logger.Debugf("POST %s/%s (%s)", s.APIs[i].URL, endpoint, s.Name)
m, err = apis[i].postPayload(endpoint, payload)
if err == nil {
return m, err
}
s.APIs[i].Healthy = false
logger.Debugf("POST %s/%s (%s) returned: %v", s.APIs[i].URL, endpoint, s.Name, err)
}
return nil, err
}
// healthyAPIs returns a list of APIs with Healthy set to true or returns an error when there are
// no healthy APIs
func (s *Sensu) healthyAPIs() ([]*API, error) {
var healthyAPIs []*API
for i := range s.APIs {
api := &s.APIs[i]
if api.Healthy {
healthyAPIs = append(healthyAPIs, api)
}
}
if len(healthyAPIs) < 1 {
return healthyAPIs, fmt.Errorf("No healthy APIs available for datacenter: %s", s.Name)
}
return healthyAPIs, nil
}
// makeRange returns an []int range from 0 to length - 1
func makeRange(length int) []int {
a := make([]int, length)
for i := range a {
a[i] = i
}
return a
}
// shuffle the provided []int
func shuffle(intRange []int) []int {
shuffledRange := make([]int, len(intRange))
copy(shuffledRange, intRange)
rand.Seed(time.Now().UnixNano())
for i := range shuffledRange {
j := rand.Intn(i + 1)
shuffledRange[i], shuffledRange[j] = shuffledRange[j], shuffledRange[i]
}
return shuffledRange
}