目录

Orchestrator总体结构... 

　　测试环境信息... 

Orchestrator详细配置... 

　　SSH免密配置... 

　　/etc/hosts配置... 

　　visudo配置... 

　　/etc/orchestrator.conf.json

　　orch_hook.sh. 

　　orch_vip.sh. 

MySQL Server配置... 

测试导换... 

　　启动orchestrator. 

　　登录Web并发现实例... 

　　切换前... 

　　切换后... 

　　Orchestrator是如何监测Master异常的...

总结... 

参考资料

Orchestrator是最近非常流行的MySQL复制管理工具。相关的资料也相当的多，但是总是缺点什么。

那就是步骤不够详细，按照博客的操作，很多都无法成功。说实话，看了N多博客后，我倒腾了一周时间才成功。

特别是Orchestrator后台也使用MySQL存储，这样容易把人绕进去了(分不清参数哪个是Orchestrator用，哪个是连接mysql实例用了）。

所以在这个博客，我将使用Sqlite存储。并把每一步操作都详细列举出来。

Orchestrator总体结构

一图胜千言。上图就是Orchestrator的架构图。

图中：Sqlite/MySQL，是Orchestrator的后端存储数据库（存储监控的mysql复制实例的相关状态信息），可以选择MySQL，也可以选择SQLite。

/etc/orchestrator.conf.json是配置文件，Orchestrator启动时读取。

下面部分是监控的MySQL的实例，本例中，我是搭建的一主，两从。当然，实际上Orchestrator可以监控成百上千个MySQL复制集群。

测试环境信息

orch 192.168.56.130  

host01 192.168.56.103

host02 192.168.56.104

host03: 192.168.56.105

Orchestrator详细配置

SSH免密配置

参考如下链接，在这里，我创建的是orch帐号。创建免费登录的作用是shell脚本通过ssh登录Mysql服务器进行VIP切换。

 https://www.cnblogs.com/chasetimeyang/p/15064507.html

/etc/hosts配置

同样，用于Shell脚本。

[orch@orch orchestrator]$ cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.56.103 host01
192.168.56.104 host02
192.168.56.105 host03
192.168.56.130 orch

visudo配置

因为我的VIP shell导换脚本内，用到了sudo执行高权限命令。你可以通过如下方法把用户加入sudo权限。

$visudo

orch ALL=(ALL) NOPASSWD: ALL

/etc/orchestrator.conf.json

如下两个参数是连接要监控的MySQL实例的连接用户名和密码
"MySQLTopologyUser": "orchestrator",
"MySQLTopologyPassword": "orc_topology_password",

如下说明是Sqlite作为后端存储数据库
"BackendDB": "sqlite",
"SQLite3DataFile": "/usr/local/orchestrator/orchestrator.sqlite3",

如下参数是实例导换后，多长时间内不允许再次导换。默认是60分钟。
"FailureDetectionPeriodBlockMinutes": 5,

如下参数是指，恢复匹配任何实例。（你也可以配置匹配规则，如此满足规则是会自动导换。不满足的，出现问题时，只能手动导换）
"RecoverMasterClusterFilters": [
"*"
],
"RecoverIntermediateMasterClusterFilters": [
"*"
],　

是否自动导换。
"ApplyMySQLPromotionAfterMasterFailover": true,

这个是导换后执行的脚本
"PostFailoverProcesses": [
"echo '(for all types) Recovered from {failureType} on {failureCluster}. Failed: {failedHost}:{failedPort}; Successor: {successorHost}:{successorPort}' >> /tmp/recovery.log",
"/home/orch/orch_hook.sh {failureType} {failureClusterAlias} {failedHost} {successorHost} >> /tmp/orch.log"
],

[orch@orch ~]$ cat /etc/orchestrator.conf.json
{
"Debug": true,
"EnableSyslog": false,
"ListenAddress": ":3000",
"MySQLTopologyUser": "orchestrator",
"MySQLTopologyPassword": "orc_topology_password",
"MySQLTopologyCredentialsConfigFile": "",
"MySQLTopologySSLPrivateKeyFile": "",
"MySQLTopologySSLCertFile": "",
"MySQLTopologySSLCAFile": "",
"MySQLTopologySSLSkipVerify": true,
"MySQLTopologyUseMutualTLS": false,
"BackendDB": "sqlite",
"SQLite3DataFile": "/usr/local/orchestrator/orchestrator.sqlite3",
"MySQLConnectTimeoutSeconds": 1,
"DefaultInstancePort": 3306,
"DiscoverByShowSlaveHosts": true,
"InstancePollSeconds": 5,
"DiscoveryIgnoreReplicaHostnameFilters": [
"a_host_i_want_to_ignore[.]example[.]com",
".*[.]ignore_all_hosts_from_this_domain[.]example[.]com",
"a_host_with_extra_port_i_want_to_ignore[.]example[.]com:3307"
],
"UnseenInstanceForgetHours": 240,
"SnapshotTopologiesIntervalHours": 0,
"InstanceBulkOperationsWaitTimeoutSeconds": 10,
"HostnameResolveMethod": "default",
"MySQLHostnameResolveMethod": "@@hostname",
"SkipBinlogServerUnresolveCheck": true,
"ExpiryHostnameResolvesMinutes": 60,
"RejectHostnameResolvePattern": "",
"ReasonableReplicationLagSeconds": 10,
"ProblemIgnoreHostnameFilters": [],
"VerifyReplicationFilters": false,
"ReasonableMaintenanceReplicationLagSeconds": 20,
"CandidateInstanceExpireMinutes": 1,
"AuditLogFile": "",
"AuditToSyslog": false,
"RemoveTextFromHostnameDisplay": ".mydomain.com:3306",
"ReadOnly": false,
"AuthenticationMethod": "",
"HTTPAuthUser": "",
"HTTPAuthPassword": "",
"AuthUserHeader": "",
"PowerAuthUsers": [
"*"
],
"ClusterNameToAlias": {
"127.0.0.1": "test suite"
},
"ReplicationLagQuery": "",
"DetectClusterAliasQuery": "SELECT SUBSTRING_INDEX(@@hostname, '.', 1)",
"DetectClusterDomainQuery": "",
"DetectInstanceAliasQuery": "",
"DetectPromotionRuleQuery": "",
"DataCenterPattern": "[.]([^.]+)[.][^.]+[.]mydomain[.]com",
"PhysicalEnvironmentPattern": "[.]([^.]+[.][^.]+)[.]mydomain[.]com",
"PromotionIgnoreHostnameFilters": [],
"DetectSemiSyncEnforcedQuery": "",
"ServeAgentsHttp": false,
"AgentsServerPort": ":3001",
"AgentsUseSSL": false,
"AgentsUseMutualTLS": false,
"AgentSSLSkipVerify": false,
"AgentSSLPrivateKeyFile": "",
"AgentSSLCertFile": "",
"AgentSSLCAFile": "",
"AgentSSLValidOUs": [],
"UseSSL": false,
"UseMutualTLS": false,
"SSLSkipVerify": false,
"SSLPrivateKeyFile": "",
"SSLCertFile": "",
"SSLCAFile": "",
"SSLValidOUs": [],
"URLPrefix": "",
"StatusEndpoint": "/api/status",
"StatusSimpleHealth": true,
"StatusOUVerify": false,
"AgentPollMinutes": 60,
"UnseenAgentForgetHours": 6,
"StaleSeedFailMinutes": 60,
"SeedAcceptableBytesDiff": 8192,
"PseudoGTIDPattern": "",
"PseudoGTIDPatternIsFixedSubstring": false,
"PseudoGTIDMonotonicHint": "asc:",
"DetectPseudoGTIDQuery": "",
"BinlogEventsChunkSize": 10000,
"SkipBinlogEventsContaining": [],
"ReduceReplicationAnalysisCount": true,
"FailureDetectionPeriodBlockMinutes": 5,
"FailMasterPromotionOnLagMinutes": 0,
"RecoveryPeriodBlockSeconds": 3600,
"RecoveryIgnoreHostnameFilters": [],
"RecoverMasterClusterFilters": [
"*"
],
"RecoverIntermediateMasterClusterFilters": [
"*"
],
"OnFailureDetectionProcesses": [
"echo 'Detected {failureType} on {failureCluster}. Affected replicas: {countSlaves}' >> /tmp/recovery.log"
],
"PreGracefulTakeoverProcesses": [
"echo 'Planned takeover about to take place on {failureCluster}. Master will switch to read_only' >> /tmp/recovery.log"
],
"PreFailoverProcesses": [
"echo 'Will recover from {failureType} on {failureCluster}' >> /tmp/recovery.log"
],
"PostFailoverProcesses": [
"echo '(for all types) Recovered from {failureType} on {failureCluster}. Failed: {failedHost}:{failedPort}; Successor: {successorHost}:{successorPort}' >> /tmp/recovery.log",
"/home/orch/orch_hook.sh {failureType} {failureClusterAlias} {failedHost} {successorHost} >> /tmp/orch.log"
],
"PostUnsuccessfulFailoverProcesses": [],
"PostMasterFailoverProcesses": [
"echo 'Recovered from {failureType} on {failureCluster}. Failed: {failedHost}:{failedPort}; Promoted: {successorHost}:{successorPort}' >> /tmp/recovery.log"
],
"PostIntermediateMasterFailoverProcesses": [
"echo 'Recovered from {failureType} on {failureCluster}. Failed: {failedHost}:{failedPort}; Successor: {successorHost}:{successorPort}' >> /tmp/recovery.log"
],
"PostGracefulTakeoverProcesses": [
"echo 'Planned takeover complete' >> /tmp/recovery.log"
],
"CoMasterRecoveryMustPromoteOtherCoMaster": true,
"DetachLostSlavesAfterMasterFailover": true,
"ApplyMySQLPromotionAfterMasterFailover": true,
"PreventCrossDataCenterMasterFailover": false,
"PreventCrossRegionMasterFailover": false,
"MasterFailoverDetachReplicaMasterHost": false,
"MasterFailoverLostInstancesDowntimeMinutes": 0,
"PostponeReplicaRecoveryOnLagMinutes": 0,
"OSCIgnoreHostnameFilters": [],
"GraphiteAddr": "",
"GraphitePath": "",
"GraphiteConvertHostnameDotsToUnderscores": true,
"ConsulAddress": "",
"ConsulAclToken": "",
"ConsulKVStoreProvider": "consul"
}

orch_hook.sh

#!/bin/bash
isitdead=$1
#cluster=$2
oldmaster=$3
newmaster=$4

ssh=$(which ssh)

logfile="/home/orch/orch_hook.log"
interface='enp0s3'
user=orch
#VIP=$($ssh -tt ${user}@${oldmaster} "sudo ip address show dev enp0s3|grep -w 'inet'|tail -n 1|awk '{print \$2}'|awk -F/ '{print \$1}'")
VIP='192.168.56.200'
VIP_TEMP=$($ssh -tt ${user}@${oldmaster} "sudo ip address|sed -nr 's#^.*inet (.*)/32.*#\1#gp'")
#remove '\r' at the end $'192.168.56.200\r'
VIP_TEMP=$(echo $VIP_TEMP|awk -F"\\r" '{print $1}')

if [ ${#VIP_TEMP} -gt 0 ]; then
    VIP=$VIP_TEMP
fi
echo ${VIP}
echo ${interface}

if [[ $isitdead == "DeadMaster" ]]; then
        if [ !-z ${!VIP} ] ; then

                echo $(date)
                echo "Revocering from: $isitdead"
                echo "New master is: $newmaster"
                echo "/home/orch/orch_vip.sh -d 1 -n $newmaster -i ${interface} -I $VIP -u ${user} -o ${oldmaster}"
                /home/orch/orch_vip.sh -d 1 -n $newmaster -i ${interface} -I $VIP -u ${user} -o ${oldmaster}
        else

                echo "Cluster does not exist!" | tee $logfile

        fi
fi

orch_vip.sh

#!/bin/bash

function usage {
  cat << EOF
 usage: $0 [-h] [-d master is dead] [-o old master ] [-s ssh options] [-n new master] [-i interface] [-I] [-u SSH user]

 OPTIONS:
    -h        Show this message
    -o string Old master hostname or IP address
    -d int    If master is dead should be 1 otherweise it is 0
    -s string SSH options
    -n string New master hostname or IP address
    -i string Interface exmple eth0:1
    -I string Virtual IP
    -u string SSH user
EOF

}

while getopts ho:d:s:n:i:I:u: flag; do
  case $flag in
    o)
      orig_master="$OPTARG";
      ;;
    d)
      isitdead="${OPTARG}";
      ;;
    s)
      ssh_options="${OPTARG}";
      ;;
    n)
      new_master="$OPTARG";
      ;;
    i)
      interface="$OPTARG";
      ;;
    I)
      vip="$OPTARG";
      ;;
    u)
      ssh_user="$OPTARG";
      ;;
    h)
      usage;
      exit 0;
      ;;
    *)
      usage;
      exit 1;
      ;;
  esac
done


if [ $OPTIND -eq 1 ]; then
    echo "No options were passed";
    usage;
fi

shift $(( OPTIND - 1 ));

# discover commands from our path
ssh=$(which ssh)
arping=$(which arping)
ip2util=$(which ip)
#ip2util='ip'

# command for adding our vip
cmd_vip_add="sudo -n $ip2util address add $vip dev $interface"
# command for deleting our vip
cmd_vip_del="sudo -n $ip2util address del $vip/32 dev $interface"
# command for discovering if our vip is enabled
cmd_vip_chk="sudo -n $ip2util address show dev $interface to ${vip%/*}/32"
# command for sending gratuitous arp to announce ip move
cmd_arp_fix="sudo -n $arping -c 1 -I ${interface} ${vip%/*}"
# command for sending gratuitous arp to announce ip move on current server
#cmd_local_arp_fix="sudo -n $arping -c 1 -I ${interface} ${vip%/*}"
cmd_local_arp_fix="$arping -c 1 -I ${interface} ${vip%/*}"

vip_stop() {
    rc=0
    echo $?

    echo "$ssh ${ssh_options} -tt ${ssh_user}@${orig_master} \
       \"[ -n \"\$(${cmd_vip_chk})\" ] && ${cmd_vip_del} && \
       sudo -n ${ip2util} route flush cache || [ -z \"\$(${cmd_vip_chk})\" ]\""

    # ensure the vip is removed
    $ssh ${ssh_options} -tt ${ssh_user}@${orig_master} \
       "[ -n \"\$(${cmd_vip_chk})\" ] && ${cmd_vip_del} && \
       sudo -n ${ip2util} route flush cache || [ -z \"\$(${cmd_vip_chk})\" ]"
    rc=$?
    return $rc
}

vip_start() {
    rc=0

    # ensure the vip is added
    # this command should exit with failure if we are unable to add the vip
    # if the vip already exists always exit 0 (whether or not we added it)
    echo "$ssh ${ssh_options} -tt ${ssh_user}@${new_master} \
     \"[ -z \"\$(${cmd_vip_chk})\" ] && ${cmd_vip_add} && ${cmd_arp_fix} || [ -n \"\$(${cmd_vip_chk})\" ]\""

    $ssh ${ssh_options} -tt ${ssh_user}@${new_master} \
     "[ -z \"\$(${cmd_vip_chk})\" ] && ${cmd_vip_add} && ${cmd_arp_fix} || [ -n \"\$(${cmd_vip_chk})\" ]"
    rc=$?
    echo "vip started"
    #$cmd_local_arp_fix
    return $rc
}

vip_status() {
    $arping -c 1 -I ${interface} ${vip%/*}
    echo "$arping -c 1 -I ${interface} ${vip%/*}"
    if ping -c 1 -W 1 "$vip"; then
        return 0
    else
        return 1
    fi
}

if [[ $isitdead == 0 ]]; then
    echo "Online failover"
    if vip_stop; then
        if vip_start; then
            echo "$vip is moved to $new_master."
        else
            echo "Can't add $vip on $new_master!"
            exit 1
        fi
    else
        echo $rc
        echo "Can't remove the $vip from orig_master!"
        exit 1
    fi
elif [[ $isitdead == 1 ]]; then
    echo "Master is dead, failover"
    # make sure the vip is not available
    if vip_status; then
        if vip_stop; then
            echo "$vip is removed from orig_master."
        else
            echo $rc
            echo "Couldn't remove $vip from orig_master."
            exit 1
        fi
    fi

    if vip_start; then
          echo "$vip is moved to $new_master."

    else
          echo "Can't add $vip on $new_master!"
          exit 1
    fi
else
    echo "Wrong argument, the master is dead or live?"

fi

MySQL Server配置

配置一下Master和不同的Slave的配置文件 (/etc/my.cnf)。所有配置参数可以一样，除了server_id。

需要注意的是每个MySQL的server_id必须不同。

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

log-error=/var/lib/mysql/mysqld.log
pid-file=/var/lib/mysql/mysqld.pid

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
port = 3306
#GTID:
server_id=135 #服务器id
gtid_mode=on #开启gtid模式
enforce_gtid_consistency=on #强制gtid一致性，开启后对于特定create table不被支持
#binlog
log_bin=binlog
log-slave-updates=1
binlog_format=row #强烈建议，其他格式可能造成数据不一致
#relay log
skip_slave_start=1
max_connect_errors=1000
default_authentication_plugin = 'mysql_native_password'

slave_net_timeout = 4

从机连接主机，并开启复制

mysql>change master to master_host='master', master_port=3306, master_user='repl', master_password='Xiaopang*803',

master_auto_position=1,MASTER_HEARTBEAT_PERIOD=2,MASTER_CONNECT_RETRY=1, MASTER_RETRY_COUNT=86400;

mysql>start slave;

复制启动无误后。在Master上执行如下命令创建orchestrator用户并赋予权限(这就是上面Orachestrator用来连接MySQL复制实例的用户）

CREATE USER 'orchestrator'@'%' IDENTIFIED BY 'orc_topology_password';
GRANT SUPER, PROCESS, REPLICATION SLAVE, REPLICATION CLIENT, RELOAD ON *.* TO 'orchestrator'@'%';

测试导换

启动orchestrator

[orch@orch orchestrator]$ pwd
/usr/local/orchestrator

[root@orch orchestrator]# ./orchestrator --debug --config=/etc/orchestrator.conf.json http

登录Web并发现实例

我的orchestrator的IP地址是130。

http://192.168.56.130:3000/

发现新的实例是，填上当前的Master的实例IP与端口。

切换前

手动给host03增加一个VIP地址 192.168.56.200

[root@host03 ~]# ip addr add dev enp0s3 192.168.56.200/32

查看一下

[root@host03 ~]# ip addr show dev enp0s3

enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 08:00:27:9a:25:16 brd ff:ff:ff:ff:ff:ff

    inet 192.168.56.105/24 brd 192.168.56.255 scope global enp0s3

       valid_lft forever preferred_lft forever

    inet 192.168.56.200/32 scope global enp0s3

       valid_lft forever preferred_lft forever

    inet6 fe80::bfdd:5d6a:d4f9:6f95/64 scope link

       valid_lft forever preferred_lft forever

    inet6 fe80::5a97:c3c9:a9df:466f/64 scope link tentative dadfailed

       valid_lft forever preferred_lft forever

切换后

停止host03 MySQL

[root@host03 ~]#service mysqld stop

停止后，过了1分多钟，服务发了导换。新的拓扑结构变为如下

 查看VIP是否也发生了切换。如下可以看到新的VIP已经切换到了新的主机host01上。

 [root@host01 ~]# ip addr show dev enp0s3

2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 08:00:27:28:0d:72 brd ff:ff:ff:ff:ff:ff

    inet 192.168.56.103/24 brd 192.168.56.255 scope global enp0s3

       valid_lft forever preferred_lft forever

    inet 192.168.56.200/32 scope global enp0s3

       valid_lft forever preferred_lft forever

    inet6 fe80::8428:fc7:68fc:1079/64 scope link

       valid_lft forever preferred_lft forever

    inet6 fe80::bfdd:5d6a:d4f9:6f95/64 scope link tentative dadfailed

       valid_lft forever preferred_lft forever

    inet6 fe80::5a97:c3c9:a9df:466f/64 scope link tentative dadfailed

       valid_lft forever preferred_lft forever

 

[root@host03 ~]# ip addr show dev enp0s3

2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 08:00:27:9a:25:16 brd ff:ff:ff:ff:ff:ff

    inet 192.168.56.105/24 brd 192.168.56.255 scope global enp0s3

       valid_lft forever preferred_lft forever

    inet6 fe80::bfdd:5d6a:d4f9:6f95/64 scope link

       valid_lft forever preferred_lft forever

    inet6 fe80::5a97:c3c9:a9df:466f/64 scope link tentative dadfailed

       valid_lft forever preferred_lft forever

Orchestrator是如何监测Master异常的

Orchestrator不仅仅只依靠Master独立来判断的。实际上它还会联系各个Slave。

当Slave达成共识Master挂掉了时，这时Orchestrator才会发生导换。

如此能够保证更高的可靠性。

Failure detection

orchestrator uses a holistic approach to detect master and intermediate master failures.

In a naive approach, a monitoring tool would probe the master, for example, and alert when it cannot contact or query the master server. Such approach is susceptible to false positives caused by network glitches. The naive approach further mitigates false positives by running n tests spaced by t-long intervals. This reduces, in some cases, the chances of false positives, and then increases the response time in the event of real failure.

orchestrator harnesses the replication topology. It observes not only the server itself, but also its replicas. For example, to diagnose a dead master scenario, orchestrator must both:

• Fail to contact said master
• Be able to contact master's replicas, and confirm they, too, cannot see the master.

Instead of triaging the error by time, orchestrator triages by multiple observers, the replication topology servers themselves. In fact, when all of a master's replicas agree that they cannot contact their master, the replication topology is broken de-facto, and a failover is justified.

orchestrator's holistic failure detection approach is known to be very reliable in production.

总结

1）orch_hook脚本是从网上找的。相对于自己的环境改了一些地方。

     这个肯定不完善，会存在一些bug。这个实验的另一目的也是验证Orchestrator的hook脚本的工作是否有效。

2）通过自己写脚本的方案，感觉还是容易出问题。其实，在有现成的更好的方案下，尽量不要自己写。

     比如说，我觉得采用半同步+keepbyalive实现VIP的方案可能更好。一个Master两个Slave，一个配置为半同步(SlaveSync)，其它的从结点配置为异步。

     Master和SlaveSync，通过keepbyalive实现VIP切换(Orchestrator  Hook启停keepbyalive服务实现VIP切换）

3）网上说有更佳的办法通过ProxySQL+Orchestartor，下次试一下。

参考资料

列出部分参考资料

https://www.cnblogs.com/zhoujinyi/p/10394389.html

https://www.jianshu.com/p/91833222581a

https://github.com/openark/orchestrator/