我們對Linkerd——本地運行完整案例，進(jìn)行進(jìn)一步的擴展，支持負(fù)載均衡。

新建兩個微服務(wù)

兩個微服務(wù)在同一個目錄下，相當(dāng)于一個服務(wù)啟動了兩個實例。目錄結(jié)構(gòu)如下：
+microservice
-response.json
-response1.json

• response.json

{"name":"James","nation":"china","msg":"Hello World."}

啟動服務(wù)：

$ python -m http.server 9999

• response1.json

{"name":"Charlse","nation":"china","msg":"Hello beijing."}

啟動服務(wù)：

$ python -m http.server 9099

新建兩個客戶端服務(wù)

每個客戶端負(fù)責(zé)調(diào)用一個微服務(wù)。

• request.py

import requests
import threading,time

class SendRequest(threading.Thread):
  def __init__(self,interval,count):
    threading.Thread.__init__(self)
    self.interval = interval
    self.count = count
  def run(self):
    try:
      url = "http://localhost:4140/response.json"
      headers={"Host":"web"}
      result = requests.get(url,headers=headers)
      print(time.strftime('%Y-%m-%d %X',time.localtime())+" - "+str(self.count)+" - "+result.text)
      self.count = self.count+1 
    except Exception as e:
      print(e)
    finally:
      SendRequest(self.interval,self.count).start()

if __name__ == '__main__':
  count = 1
  SendRequest(0.1,count).start()

• request1.py

import requests
import threading,time

class SendRequest(threading.Thread):
  def __init__(self,interval,count):
    threading.Thread.__init__(self)
    self.interval = interval
    self.count = count
  def run(self):
    try:
      url = "http://localhost:4140/response1.json"
      headers={"Host":"web"}
      result = requests.get(url,headers=headers)
      print(time.strftime('%Y-%m-%d %X',time.localtime())+" - "+str(self.count)+" - "+result.text)
      self.count = self.count+1 
    except Exception as e:
      print(e)
    finally:
      SendRequest(self.interval,self.count).start()

if __name__ == '__main__':
  count = 1
  SendRequest(0.1,count).start()

啟動客戶端

$ python request.py
$ python request1.py

最后看linkerd負(fù)載均衡配置

• 首先配置disco/web

127.0.0.1 9999
127.0.0.1 9099

• 再配置config/linkerd.yaml

routers:
- protocol: http
  dtab: |
    /wadd => /#/io.l5d.fs;
    /svc => /wadd/web
  httpAccessLog: logs/access.log
  label: web
  servers:
  - port: 4140
    ip: 0.0.0.0
  client:
    failureAccrual:
      kind: io.l5d.successRate
      successRate: 0.99
      requests: 1000
    loadBalancer:
      kind: p2c
      maxEffort: 5

這里loadBalancer算法采用的是p2c（其實默認(rèn)是p2c，不用特別配置），你也可以配置成別的，參考官方文檔。

啟動linkerd

admin UI

火狐截圖_2017-12-26T11-26-06.439Z.png

微服務(wù)后臺日志

我啟動了三個request1.py客戶端，所以看起來后臺response1.json多一些

127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -
127.0.0.1 - - [26/Dec/2017 19:27:33] "GET /response1.json HTTP/1.1" 200 -