服務發現 consul cluster 的搭建
阿新 • • 發佈：2018-09-02
form 127.0.0.1 holding 檢測 raft select controls nts spec
consul cluster setup
- 介紹和指南:
consul用於服務發現.當底層服務發生變化時,能及時更新正確的mysql服務IP. 並提供給業務查詢.但需要自行編寫腳本,監測數據庫狀態和切斷故障服務器的對外提供服務.
https://www.consul.io/intro/getting-started/install.html
環境:
consul cluster node
node1:192.168.99.183
node1:192.168.99.184
node1:192.168.99.185
agent(client)/安裝在mysql服務器上
agent1:192.168.99.210(mysql master)
agent2:192.168.99.211(mysql slave1)
agent3:192.168.99.212(mysql slave2)
安裝:
cd /opt wget https://releases.hashicorp.com/consul/1.2.2/consul_1.2.2_linux_amd64.zip unzip consul_1.2.2_linux_amd64.zip cd /usr/bin/ ln -s /opt/consul consul mkdir /data/consul/ /etc/consul.d/ \\安裝完成： #consul Usage: consul [--version] [--help] <command> [<args>] Available commands are: agent Runs a Consul agent catalog Interact with the catalog connect Interact with Consul Connect event Fire a new event exec Executes a command on Consul nodes force-leave Forces a member of the cluster to enter the "left" state info Provides debugging information for operators. intention Interact with Connect service intentions join Tell Consul agent to join cluster keygen Generates a new encryption key keyring Manages gossip layer encryption keys kv Interact with the key-value store leave Gracefully leaves the Consul cluster and shuts down lock Execute a command holding a lock maint Controls node or service maintenance mode members Lists the members of a Consul cluster monitor Stream logs from a Consul agent operator Provides cluster-level tools for Consul operators reload Triggers the agent to reload configuration files rtt Estimates network round trip time between nodes snapshot Saves, restores and inspects snapshots of Consul server state validate Validate config files/directories version Prints the Consul version watch Watch for changes in Consul [root@db210_09:38:25 /data/consul/script] #consul --version Consul v1.2.2 Protocol 2 spoken by default, understands 2 to 3 (agent will automatically use protocol >2 when speaking to compatible agents)
集群配置
三個節點配置基本一樣,只需要修改bind_addr、client_addr為當前服務器IP.
重要參數:
-bootstrap-expect：在一個datacenter中期望提供的server節點數目，當大於或等這個數量的server成功上線群集才對外提供服務,該標記不能和bootstrap同時存在,推薦使用bootstrap-expect方式.
#cd /etc/consul.d/ #ll -rwxr-xr-x. 1 root root 403 Aug 29 10:21 server.json \\如果沒有x屬性,使用:chmod +x server.json [root@db5_09:44:18 /etc/consul.d] #cat server.json { "data_dir": "/data/consul", "datacenter": "dc1", "log_level": "INFO", "server": true, "bootstrap_expect": 2, \\第一個節點需要此配置 "bind_addr": "192.168.99.185", "client_addr": "192.168.99.185", "ports":{ "dns":53 }, "ui":true, "retry_join": ["192.168.99.183","192.168.99.184","192.168.99.185"], "retry_interval":"3s", "raft_protocol":3, "rejoin_after_leave":true }
集群啟動
先啟動帶 "bootstrap_expect": 2,標簽的server。啟動命令：
[root@db210_11:10:21 /etc/consul.d]
#consul agent --config-dir=/etc/consul.d >/data/consul/consul.log 2>&1 &查看集群成員
[root@db3_09:52:27 /etc/consul.d] 用執著守候成功
#consul members --http-addr=192.168.99.183:8500
Node Address Status Type Build Protocol DC Segment
db3 192.168.99.183:8301 alive server 1.2.2 2 dc1 <all>
db4 192.168.99.184:8301 alive server 1.2.2 2 dc1 <all>
db5 192.168.99.185:8301 alive server 1.2.2 2 dc1 <all>
此種狀態就可以添加服務器的註冊了.
Client節點配置
配置分為三部分:
1.註冊client配置,用於與consul集群serrver通信,配置文件:/etc/consul.d/agent.json
2.註冊應用服務(mysql)的配置,配置文件:/etc/consul.d/r_db3308.json(slave的只讀服務),w_db3308.json(master 服務)
3.檢測master或slave是否健康的python腳本,配置文件:/data/consul/script/check_mysql.py
- agent.json部分:
#cd /etc/consul.d/
[root@db210_10:16:22 /etc/consul.d]
#ll
total 12
-rwxr-xr-x 1 root root 316 Aug 29 10:41 agent.json
-rwxr-xr-x 1 root root 349 Sep 1 22:10 r_db3308.json
-rwxr-xr-x 1 root root 350 Sep 1 22:13 w_db3308.json
[root@db210_10:16:23 /etc/consul.d]
#cat agent.json
{
"data_dir": "/data/consul",
"enable_script_checks": true,
"bind_addr": "192.168.99.210",
"retry_join": ["192.168.99.183","192.168.99.184","192.168.99.185"],
"retry_interval": "30s",
"rejoin_after_leave": true,
"start_join": ["192.168.99.183","192.168.99.184","192.168.99.185"]
}
[root@db210_10:19:50 /etc/consul.d]
此部分內容和群集server註冊內容差不多.- r_db3308.json和cat w_db3308.json部分 :
[root@db210_10:16:22 /etc/consul.d]
#ll
total 12
-rwxr-xr-x 1 root root 316 Aug 29 10:41 agent.json
-rwxr-xr-x 1 root root 349 Sep 1 22:10 r_db3308.json
-rwxr-xr-x 1 root root 350 Sep 1 22:13 w_db3308.json
[root@db210_10:19:50 /etc/consul.d]
#cat r_db3308.json
{
"service":
{
"name":"r_db3508",
"tags":[
"zstdb3508"
],
"address":"192.168.99.210",
"port":3508,
"check":
{
"args":[
"/data/consul/script/check_mysql.py",
"slave"
],
"interval":"5s"
}
}
}
[root@db210_10:22:18 /etc/consul.d]
#cat w_db3308.json
{
"service":
{
"name":"w_db3508",
"tags":[
"zstdb3508"
],
"address":"192.168.99.210",
"port":3508,
"check":
{
"args":[
"/data/consul/script/check_mysql.py",
"master"
],
"interval":"5s"
}
}
}
- check_mysql.py(檢查主從節點狀態腳本)
[root@db212_11:40:41 /data/consul/script]
#cat check_mysql.py
#!/usr/bin/env python2
#-*- coding: utf-8 -*-
# Script Name: mysql_check.py
# Description: check mysql servers status
# Author: Wenyz
# Create Date: 2018/08/29
import os,sys
import time
import datetime
import MySQLdb
import getpass
check_item=sys.argv[1]
print (datetime.datetime.now().strftime(‘%Y-%m-%d %H:%M:%S‘))
print "check_item:%s"%check_item
#check_item="master"
host=‘127.0.0.1‘
user=‘wyz‘
password=‘*****‘
port = 3508
database=‘wenyz‘
def mysql_connect():
try:
conn = MySQLdb.connect(host = host, user = user ,passwd = password,port = port, db = database)
return conn.cursor()
except MySQLdb.Error,e:
try:
print "Error %d:%s"%(e.args[0],e.args[1])
except IndexError:
print "MySQL Error:%s" % str(e)
sys.exit(1)
def validate_select():
try:
cursor = mysql_connect()
cursor.execute(‘use wenyz;‘)
cursor.execute(‘select * from t2 limit 2;‘)
result_set=cursor.fetchall()
if result_set[0][0] == 4079861: #id
print "the frist rowid is %s"%result_set[0][0]
print ‘Successfully query data!‘
else:
print "the vaule is %s"%result_set[0][0]
return ‘successfully‘
except MySQLdb.Error,e:
print "Error %d:%s"%(e.args[0],e.args[1])
print "MySQL Error:%s" % str(e)
print "Query data failed"
return ‘failed‘
cursor.close()
conn.close()
#validate_select()
def check_mysql_variable(var_key):
try:
cursor = mysql_connect()
sql="show global variables like \‘%s\‘"%var_key
cursor.execute(sql)
variable_set=cursor.fetchall()
show_var={}
for r in variable_set:
show_var[r[0]]=r[1]
return show_var[var_key]
except MySQLdb.Error,e:
try:
print "Error %d:%s"%(e.args[0],e.args[1])
except IndexError:
print "MySQL Error:%s" % str(e)
sys.exit(1)
cursor.close()
conn.close()
def set_var(key_name,key_value):
try:
cursor = mysql_connect()
sql="set global %s=%s"%(key_name,key_value)
cursor.execute(sql)
except MySQLdb.Error,e:
try:
print "Error %d:%s"%(e.args[0],e.args[1])
except IndexError:
print "MySQL Error:%s" % str(e)
sys.exit(2)
cursor.close()
def isslave():
try:
conn = MySQLdb.connect(host = host, user = user ,passwd = password,port = port, db = database)
cursor=conn.cursor(cursorclass=MySQLdb.cursors.DictCursor)
cursor.execute("show slave status")
slave_status = cursor.fetchone()
va_slave_status={}
if slave_status !=None:
if slave_status[‘Slave_IO_Running‘]==‘Yes‘ and slave_status[‘Slave_SQL_Running‘]==‘Yes‘:
print "This is a slave & Slave_SQL_Running and Slave_IO_Running are both YES"
return ‘Yes‘
else:
print "This is a slave,but Slave_SQL_Running or Slave_IO_Running is not YES"
return ‘yes‘
else:
# print type(slave_status)
print "show slave status:%s"%slave_status
print "Slave replication setup error or this is master"
return ‘no‘
except IndexError:
print "show slave failed,%s"%str(e)
sys.exit(2)
if check_item==‘master‘:
try:
vs=validate_select()
isslave=isslave()
c_read_only=check_mysql_variable("read_only")
c_super_read_only=check_mysql_variable("super_read_only")
if vs==‘successfully‘ and isslave==‘no‘ and c_read_only==‘OFF‘ and c_super_read_only==‘OFF‘:
print "It‘s a healthy master,select t2:%s,isslave:%s ,read_only:%s,super_read_only:%s"%(vs,isslave,c_read_only,c_super_read_only)
sys.exit(0)
else:
print "It‘s not a healthy master,select t2:%s,isslave:%s ,read_only:%s,super_read_only:%s"%(vs,isslave,c_read_only,c_super_read_only)
sys.exit(2)
except IndexError:
print "show slave failed,%s"%str(e)
sys.exit(2)
elif check_item==‘slave‘:
try:
vs=validate_select()
isslave=isslave()
c_read_only=check_mysql_variable("read_only")
c_super_read_only=check_mysql_variable("super_read_only")
# print slave_status,type(slave_status)
#print "Isslave is yes but read_only is off,will set to on %s,%s,%s"%(isslave,c_read_only,c_super_read_only)
if isslave=="Yes" and (c_read_only=="OFF" or c_super_read_only=="OFF"):
print "Isslave () is true, but read_only or super_read_only is OFF, seting this parameter to on.read_only:%s,super_read_only:%s"%(c_read_only,c_super_read_only)
set_var("read_only","ON")
set_var("super_read_only","ON")
if vs==‘successfully‘ and isslave==‘Yes‘ and c_read_only==‘ON‘ and c_super_read_only==‘ON‘:
print "It‘s a healthy slave,select t2:%s,isslave:%s ,read_only:%s,super_read_only:%s"%(vs,isslave,c_read_only,c_super_read_only)
sys.exit(0)
else:
print "It‘s not a healthy slave,select t2:%s,isslave:%s ,read_only:%s,super_read_only:%s"%(vs,isslave,c_read_only,c_super_read_only)
sys.exit(2)
except IndexError:
print "show slave failed,%s"% str(e)
sys.exit(2)
else:
print ‘The parameter is not "master" or "slave"‘
sys.exit(2)
#isslave()
Client節點啟動並查看狀態
consul agent --config-dir=/etc/consul.d/ > /data/consul/consul.log 2>&1 &
[root@db212_11:52:35 /data/consul/script]
#consul members --http-addr=192.168.99.183:8500
Node Address Status Type Build Protocol DC Segment
db3 192.168.99.183:8301 alive server 1.2.2 2 dc1 <all>
db4 192.168.99.184:8301 alive server 1.2.2 2 dc1 <all>
db5 192.168.99.185:8301 alive server 1.2.2 2 dc1 <all>
db210 192.168.99.210:8301 alive client 1.2.2 2 dc1 <default>
db211 192.168.99.211:8301 alive client 1.2.2 2 dc1 <default>
db212 192.168.99.212:8301 alive client 1.2.2 2 dc1 <default>
啟動後可以通過看web方式查看服務,並通過DNS查詢核實服務是否註冊成功:
[root@db212_11:52:56 /data/consul/script]
#nslookup
> server 192.168.99.183
Default server: 192.168.99.183
Address: 192.168.99.183#53
> w_db3508.service.consul.
Server: 192.168.99.183
Address: 192.168.99.183#53
Name: w_db3508.service.consul
Address: 192.168.99.210
> r_db3508.service.consul.
Server: 192.168.99.183
Address: 192.168.99.183#53
Name: r_db3508.service.consul
Address: 192.168.99.211
Name: r_db3508.service.consul
Address: 192.168.99.212
>
服務發現 consul cluster 的搭建