Question

I’ve read conflicting information as to whether or not the WADLogsTable table used by the DiagnosticMonitor in Windows Azure will automatically prune old log entries.

I’m guessing it doesn’t, and will instead grow forever – costing me money. 🙂

If that’s the case, does anybody have a good code sample as to how to clear out old log entries from this table manually? Perhaps based on timestamp? I’d run this code from a worker role periodically.

Answer 1

The data in tables created by Windows Azure Diagnostics isn’t deleted automatically.

However, Windows Azure PowerShell Cmdlets contain cmdlets specifically for this case.

PS D:\> help Clear-WindowsAzureLog

NAME
Clear-WindowsAzureLog

SYNOPSIS
Removes Windows Azure trace log data from a storage account.

SYNTAX
Clear-WindowsAzureLog [-DeploymentId ] [-From ] [-To ] [-StorageAccountName ] [-StorageAccountKey ] [-UseD
evelopmentStorage] [-StorageAccountCredentials ] []

Clear-WindowsAzureLog [-DeploymentId <String>] [-FromUtc <DateTime>] [-ToUt
c <DateTime>] [-StorageAccountName <String>] [-StorageAccountKey <String>]
[-UseDevelopmentStorage] [-StorageAccountCredentials <StorageCredentialsAcc
ountAndKey>] [<CommonParameters>]

You need to specify -ToUtc parameter, and all logs before that date will be deleted.

If cleanup task needs to be performed on Azure within the worker role, C# cmdlets code can be reused. PowerShell Cmdlets are published under permissive MS Public License.

Basically, there are only 3 files needed without other external dependencies: DiagnosticsOperationException.cs, WadTableExtensions.cs, WadTableServiceEntity.cs.