OpenStack Heat AutoScaling詳解及實(shí)例代碼

更新時(shí)間：2016年12月04日 14:52:44 投稿：lqh

這篇文章主要介紹了OpenStack Heat AutoScaling詳解及實(shí)例代碼的相關(guān)資料,需要的朋友可以參考下

OpenStack Heat AutoScaling

一、背景

Openstack的Heat是在H版之后加入的組件，旨在創(chuàng)建一套業(yè)務(wù)流程，更輕松的管理一個(gè)集群。集群內(nèi)的虛擬機(jī)可以作為一個(gè)整體，統(tǒng)一的為客戶提供服務(wù)。Heat中把功能定義成資源，在Heat中會(huì)用到Nova，Neutron，Ceilometer等組件，這些都可以看成是資源，通過(guò)模板文件來(lái)描述，模板文件可以是yaml格式，也可以是json格式，一般是yaml格式。
AutoScaling的概念最早出現(xiàn)在AWS，AutoScaling是一項(xiàng)Web服務(wù)，目的是根據(jù)用戶定義的策略，時(shí)間表的運(yùn)行狀態(tài)檢查啟動(dòng)或終止虛擬機(jī)，達(dá)到自動(dòng)伸縮。

Openstack里的Auto Scale是由Heat和Ceilometer模塊一起配合完成的。Ceilometer負(fù)責(zé)收集處理性能數(shù)據(jù)，一旦達(dá)到Heat模版里定義的閥值，就發(fā)告警信息給heat-engine，由heat-engine調(diào)動(dòng)Heat模版里定義的其它的OpenStack資源實(shí)現(xiàn)auto scale。

二、Heat AutoScaling Resources

實(shí)現(xiàn)AutoScaling功能涉及到的資源如下：

1.AWS::AutoScaling::AutoScalingGroup

伸縮組是具有相同應(yīng)用場(chǎng)景的實(shí)例的集合，定義了組內(nèi)實(shí)例數(shù)的最大值和最小值，冷卻時(shí)間等等。
注：冷卻時(shí)間是指一個(gè)伸縮活動(dòng)后的一段鎖定時(shí)間，在這個(gè)時(shí)間內(nèi)不能進(jìn)行其他的伸縮活動(dòng)。

語(yǔ)法如下：

{
 "Type" : "AWS::AutoScaling::AutoScalingGroup",
 "Properties" : {
  "AvailabilityZones" : [ String, ... ],
  "Cooldown" : String,
  "DesiredCapacity" : String,
  "HealthCheckGracePeriod" : Integer,
  "HealthCheckType" : String,
  "InstanceId" : String,
  "LaunchConfigurationName" : String,
  "LoadBalancerNames" : [ String, ... ],
  "MaxSize" : String,
  "MetricsCollection" : [ MetricsCollection, ... ]
  "MinSize" : String,
  "NotificationConfigurations" : [ NotificationConfigurations, ... ],
  "PlacementGroup" : String,
  "Tags" : [ Auto Scaling Tag, ..., ],
  "TargetGroupARNs" : [ String, ... ],
  "TerminationPolicies" : [ String, ..., ],
  "VPCZoneIdentifier" : [ String, ... ]
 }
}

2.AWS::AutoScaling::LaunchConfiguration

伸縮配置定義了用于彈性伸縮的實(shí)例的配置。由AutoScalingGroup用于配置組內(nèi)的實(shí)例。

語(yǔ)法如下：

{
  "Type" : "AWS::AutoScaling::LaunchConfiguration",
  "Properties" : {
   "AssociatePublicIpAddress" : Boolean,
   "BlockDeviceMappings" : [ BlockDeviceMapping, ... ],
   "ClassicLinkVPCId" : String,
   "ClassicLinkVPCSecurityGroups" : [ String, ... ],
   "EbsOptimized" : Boolean,
   "IamInstanceProfile" : String,
   "ImageId" : String,
   "InstanceId" : String,
   "InstanceMonitoring" : Boolean,
   "InstanceType" : String,
   "KernelId" : String,
   "KeyName" : String,
   "PlacementTenancy" : String,
   "RamDiskId" : String,
   "SecurityGroups" : [ SecurityGroup, ... ],
   "SpotPrice" : String,
   "UserData" : String
  }
}

3.AWS::AutoScaling::ScalingPolicy

為auto scale group添加伸縮的策略，定義了具體的擴(kuò)展或者收縮的操作，以及伸縮的數(shù)量。

語(yǔ)法如下：

{
  "Type" : "AWS::AutoScaling::ScalingPolicy",
  "Properties" : {
   "AdjustmentType" : String,
   "AutoScalingGroupName" : String,
   "Cooldown" : String,
   "EstimatedInstanceWarmup" : Integer,
   "MetricAggregationType" : String,
   "MinAdjustmentMagnitude" : Integer,
   "PolicyType" : String,
   "ScalingAdjustment" : Integer,
   "StepAdjustments" : [ StepAdjustments, ... ]
  }
}

此外，Heat中AutoScaling還需配合OS::Ceilometer::Alarm使用，由Alarm監(jiān)控實(shí)例的運(yùn)行狀況，一旦超過(guò)閾值，則會(huì)產(chǎn)生告警。

三、 Heat AutoScaling Template

下面是一個(gè)簡(jiǎn)單的例子:

heat_template_version: 2013-05-23
description: Heat template for autoscaling
parameters:#定義一些變量
 flavor:
  type: string
  default: m1.small
 image:
  type: string
  default: 1a2b3c4f-1a2b-3c4f-5d6e-4130ff5203de
 availability_zone:
  type: string
  default: nova
 alarm_scaleout_threshold:#閾值
  type: number
  default: 80
 alarm_scalein_threshold:#閾值
  type: number
  default: 20
resources:
 neutron_network:
  type: OS::Neutron::Net
  properties:
   name: {get_param: "OS::stack_name"}

 neutron_subnet:
  type: OS::Neutron::Subnet
  properties:
   name: {get_param: "OS::stack_name"}
   network_id: { get_resource: neutron_network }
   cidr: '192.168.111.0/24'
   gateway_ip: '192.168.111.1'
   allocation_pools:
    - start: '192.168.111.2'
     end: '192.168.111.254'
 neutron_router:
  type: OS::Neutron::Router
  properties:
   name: {get_param: "OS::stack_name"}
 add_router_interface:
  type: OS::Neutron::RouterInterface
  properties:
   router_id: { get_resource: neutron_router }
   subnet_id: { get_resource: neutron_subnet }
 nova_server_security_group:
  type: OS::Neutron::SecurityGroup
  properties:
   description: 'security group for VM'
   name: {get_param: "OS::stack_name"}
   rules: [
    {direction: 'ingress',
     remote_ip_prefix: '0.0.0.0/0',
     port_range_min: 0,
     port_range_max: 30000,
     ethertype: IPv4,
     protocol: 'tcp'},
    {direction: 'egress',
     remote_ip_prefix: '0.0.0.0/0',
     port_range_min: 0,
     port_range_max: 65535,
     ethertype: 'IPv4',
     protocol: 'tcp'},
    {direction: 'egress',
     remote_ip_prefix: '0.0.0.0/0',
     port_range_min: 0,
     port_range_max: 65535,
     ethertype: 'IPv4',
     protocol: 'udp'},
    {direction: 'ingress',
     remote_ip_prefix: '0.0.0.0/0',
     port_range_min: null,
     port_range_max: null,
     ethertype: 'IPv4',
     protocol: 'icmp'},
    {direction: egress,
     remote_ip_prefix: '0.0.0.0/0',
     port_range_min: null,
     port_range_max: null,
     ethertype: 'IPv4',
     protocol: 'icmp'}
   ]
 launch_config:#Scale group中的實(shí)例的配置
  type: AWS::AutoScaling::LaunchConfiguration
  properties:
   ImageId: { get_param: image }#實(shí)例使用的image
   InstanceType: { get_param: flavor }#實(shí)例使用的flavor
   SecurityGroups: [ get_resource: nova_server_security_group ]
   UserData: |#實(shí)例啟動(dòng)時(shí)運(yùn)行的腳本
     #!/bin/bash
     passwd root << EOD
     123456
     123456
     EOD
 server_group:#伸縮組
  type: AWS::AutoScaling::AutoScalingGroup
  properties:
   AvailabilityZones: []
   Cooldown: '60'#冷卻時(shí)間
   LaunchConfigurationName: { get_resource: launch_config }#組中實(shí)例的配置
   MinSize: '1'#最小實(shí)例數(shù)
   MaxSize: '4'#最大實(shí)例數(shù)
   VPCZoneIdentifier: [ get_resource: neutron_subnet ]
 scaleout_policy:#向上擴(kuò)展的策略
  type: AWS::AutoScaling::ScalingPolicy
  properties:
   AdjustmentType: ChangeInCapacity
#heat 支持三種調(diào)整方式：change_in_capacity (new = current + adjustment), #exact_capacity (new = adjustment), percent_change_in_capacity (在current 的基#礎(chǔ)上上按照 adjustment 的 百分比調(diào)整)
   AutoScalingGroupName: { get_resource: server_group }
   ScalingAdjustment: '1'#每次的調(diào)整量，即增加一個(gè)實(shí)例
 scalein_policy:#向下收縮的策略
  type: AWS::AutoScaling::ScalingPolicy
  properties:
   AdjustmentType: ChangeInCapacity
   AutoScalingGroupName: { get_resource: server_group }
   ScalingAdjustment: '-1'#每次的調(diào)整量，即減少一個(gè)實(shí)例
 neutron_port:
  type: OS::Neutron::Port
  properties:
   network_id: { get_resource: neutron_network }
   fixed_ips:
    - subnet_id: { get_resource: neutron_subnet }
   security_groups: [ { get_resource: nova_server_security_group } ]
 alarm_scaleout: #定義一個(gè) ceilometer alarm
  type: OS::Ceilometer::Alarm
  properties:
   description: Scale-up if the average CPU > 80% for 10 minute
   meter_name: cpu_util #監(jiān)控虛擬機(jī)的 cpu_util
   statistic: avg #statistic 的計(jì)算方法為 avg 即平均值法
   period: 600 #統(tǒng)計(jì)周期
   evaluation_periods: 1 #連續(xù)幾個(gè)周期才算有效
   repeat_actions: true
   threshold: { get_param: alarm_scaleout_threshold }# cpu_util 的閾值
   alarm_actions: #該告警在alarm 狀態(tài)時(shí)的 action。
    - {get_attr: [scaleout_policy, AlarmUrl]}
   matching_metadata: {'metadata.user_metadata.groupname': {get_resource: 'server_group'}}
   comparison_operator: gt #檢測(cè)值和閾值的比較方式為 gt 即大于
 alarm_scalein:
  type: OS::Ceilometer::Alarm
  properties:
   description: Scale-down if the average CPU < 20% for 10 minutes
   meter_name: cpu_util
   statistic: avg
   period: 600
   evaluation_periods: 1
   repeat_actions: true
   threshold: { get_param: alarm_scalein_threshold }
   alarm_actions:
    - {get_attr: [scalein_policy, AlarmUrl]}
   matching_metadata: {'metadata.user_metadata.groupname': {get_resource: 'server_group'}}
   comparison_operator: lt#檢測(cè)值和閾值的比較方式為 lt 即小于
outputs:
 scale_in_url:
  value: { get_attr: [ scalein_policy, AlarmUrl ] }
 scale_out_url:
  value: { get_attr: [ scaleout_policy, AlarmUrl ] }

這個(gè)stack的功能是監(jiān)控實(shí)例的CPU使用率,當(dāng)CPU使用率大于80%時(shí),將會(huì)啟動(dòng)一個(gè)新的實(shí)例,當(dāng)CPU使用率小于20%,將會(huì)減少一個(gè)實(shí)例。

感謝閱讀，希望能幫助到大家，謝謝大家對(duì)本站的支持！

您可能感興趣的文章: