嘗試讀取性能計數器時出現Azure自動縮放異常

Question

我正在從Microsoft的一個示例中演示如何使用自動縮放（http://www.windowsazure.com/en-us/develop/net/how-to-guides/autoscaling/）。安裝在雲上的工作者角色生成性能計數器，在本地，控制檯應用程序讀取此計數器並應用自動調節。

一切看起來不錯，性能計數器可從WADPerformanceCountersTable中獲得，控制檯應用程序可以正確訪問存儲，但無法在WADPerformanceCountersTable中找到工作者角色。這是所生成的例外：

Autoscaling General Error: 2001 : 
Microsoft.Practices.EnterpriseLibrary.WindowsAzure.Autoscaling.DataPointsCollection.DataPointsCollectionException: 
Could not retrieve performance counter with name '\Processor(_Total)\% Processor Time' 
for target 'WorkerRoleExample' from the WADPerformanceCountersTable table. ---> 
System.ArgumentOutOfRangeException: Could not retrieve the role with alias 'WorkerRoleExample' from the service information store. 
Please review the service information store to fix this. 

自動擴充應用程序塊的配置文件（兩個文件控制檯應用程序的一部分）：

rules.xml中：

<?xml version="1.0" encoding="utf-8" ?> 
<rules xmlns="http://schemas.microsoft.com/practices/2011/entlib/autoscaling/rules"> 
    <constraintRules> 
    <rule name="default" enabled="true" rank="1" description="The default constraint rule"> 
     <actions> 
     <range min="1" max="2" target="WorkerRoleExample"/> 
     </actions> 
    </rule> 
    </constraintRules> 
    <reactiveRules> 
    <rule name="ScaleUpOnHighUtilization" rank="10" description="Scale up the web role" enabled="true" > 
     <when> 
     <any> 
      <greaterOrEqual operand="WebRoleA_CPU_Avg_5m" than="60"/> 
     </any> 
     </when> 
     <actions> 
     <scale target="WorkerRoleExample" by="1"/> 
     </actions> 
    </rule> 
    <rule name="ScaleDownOnLowUtilization" rank="10" description="Scale up the web role" enabled="true" > 
     <when> 
     <all> 
      <less operand="WebRoleA_CPU_Avg_5m" than="60"/> 
     </all> 
     </when> 
     <actions> 
     <scale target="WorkerRoleExample" by="-1"/> 
     </actions> 
    </rule> 
    </reactiveRules> 
    <operands> 
    <performanceCounter alias="WebRoleA_CPU_Avg_5m" 
         performanceCounterName="\Processor(_Total)\% Processor Time" 
         source ="WorkerRoleExample" 
         timespan="00:05:00" aggregate="Average"/> 
    </operands> 
</rules> 

的services.xml：

<?xml version="1.0" encoding="utf-8" ?> 
<serviceModel xmlns="http://schemas.microsoft.com/practices/2011/entlib/autoscaling/serviceModel"> 
    <subscriptions> 
    <subscription name="TestingWorkerRole" 
        certificateThumbprint="**************" 
        subscriptionId="**************" 
        certificateStoreLocation="CurrentUser" 
        certificateStoreName="My"> 
     <services> 
     <service dnsPrefix="**************" slot="Staging"> 
      <roles> 
      <role alias="AutoscalingApplicationRole" 
        roleName="WorkerRoleExample" 
        wadStorageAccountName="targetstorage"/> 
      </roles> 
     </service> 
     </services> 
     <storageAccounts> 
     <storageAccount alias="targetstorage" 
      connectionString="DefaultEndpointsProtocol=https;AccountName=*****;AccountKey=*******"> 
     </storageAccount> 
     </storageAccounts> 
    </subscription> 
    </subscriptions> 
</serviceModel> 

在雲上運行的工作角色生成一個性能計數器：

public override bool OnStart() 
{ 
    // Set the maximum number of concurrent connections 
    ServicePointManager.DefaultConnectionLimit = 12; 

    CreatePerformanceCounters(); 

    return base.OnStart(); 
} 

private static void CreatePerformanceCounters() 
{ 
    DiagnosticMonitorConfiguration diagConfig = DiagnosticMonitor.GetDefaultInitialConfiguration(); 

    var procTimeConfig = new PerformanceCounterConfiguration(); 
    procTimeConfig.CounterSpecifier = @"\Processor(_Total)\% Processor Time"; 
    procTimeConfig.SampleRate = TimeSpan.FromSeconds(10); 

    diagConfig.PerformanceCounters.DataSources.Add(procTimeConfig); 
    diagConfig.PerformanceCounters.ScheduledTransferPeriod = TimeSpan.FromMinutes(1); 

    DiagnosticMonitor.Start("Microsoft.WindowsAzure.Plugins.Diagnostics.ConnectionString", diagConfig); 
} 

Answer 1

在services.xml中嘗試修改此：

<role alias="AutoscalingApplicationRole" 
       roleName="WorkerRoleExample" 
       wadStorageAccountName="targetstorage"/> 

要這樣：

<role alias="WorkerRoleExample" 
       roleName="WorkerRoleExample" 
       wadStorageAccountName="targetstorage"/> 

在rules.xml的scale元素的target屬性查找匹配的aliasattribute在role元素services.xml - 它正在尋找WorkerRoleExample並找不到它。

這也將工作如果代替上述情況，rules.xml中你改變：

<scale target="WorkerRoleExample" by="1"/> 

要這樣：

<scale target="AutoscalingApplicationRole" by="1"/>