Overview of Windows Azure Diagnostics

1. Windows Azure Diagnostics
Neil Mackenzie

2. Overview
• Motivation for Windows Azure Diagnostics
• Architecture of WAD
• Configuring WAD
• Managing WAD
• Demonstration

3. Why Windows Azure Diagnostics?
WAD Provides:
• visibility into instance VMs
• access to IIS logs, event logs and traces
• configuration of diagnostic information captured
• consistent way to persist diagnostic information
WAD Supports:
• non-intrusive investigation of problems
• auto-scaling through access to performance counters
IntelliTrace

4. WAD Architecture
Diagnostics Agent
• Runs on each instance
• Persists diagnostic data to Azure Storage
Configuration
• Instance-specific WAD configuration
• Located in an Azure Blob container
• Polled by Diagnostics Agent
Azure Storage
• WAD uses blobs, tables and queues
.NET API

5. Configuration
WAD Configuration
• Instance-specific blobs in wad-control-container
WAD Configuration specifies:
• data buffers to be captured
• data buffers to be persisted
• transfer schedule
WAD .NET API updates WAD configuration
Diagnostics Agent:
• polls WAD configuration to identify changes.
• implements changes

6. Data Buffers
WAD captures data to the data buffer
WAD persists data to the Azure Storage location
Data Buffer Azure Storage Location
Windows Azure logs * WADLogsTable
Windows Diagnostic infrastructure logs * WADDiagnosticsInfrastructureLogsTable
IIS 7.0 logs (webrole) * wad-iis-logfiles (blobs)
Failed Request logs (webrole) wad-iis-failedreqlogfiles (blobs)
Windows Event logs WADWindowsEventLogsTable
Performance counters WADPerformanceCountersTable
Crash dumps wad-crash-dumps (blobs)
Custom error logs Configurable (blobs)
* Captured by default
WADDirectoriesTable contains one entity for each blob stored by WAD

7. Custom Logging
WAD supports custom logging
Configure:
• Capture directory in local storage
• Persistence location in Azure Blob storage
• Transfer schedule

8. Persistence
Scheduled Transfers
• Routine transfers to persistent storage
• Transfer period specific to a data buffer
On-Demand Transfers
• Immediate need to persist data
• Possibility of duplicate data in persistent storage
Cleanup
• WAD does not cleanup persisted data
• Should not delete the tables/containers

9. Managing WAD
Diagnostics Agent started automatically
• Default configuration
WAD managed on a per-instance basis
• Use RoleInstanceDiagnosticManager
• Get WAD configuration for instance
• Modify WAD configuration
• Set current WAD configuration for the instance

10. On-Demand Transfers
On-Demand transfers configured for:
• Instance
• Data buffer
Use RoleInstanceDiagnosticManager
• Configure on-demand transfer
• Request on-demand transfer
Cleanup on-demand transfer
• Get completion message from WAD notification queue
• End on-demand transfer
One on-demand transfer per data buffer

11. Tools
Cerebrata
• Azure Diagnostics Manager
Microsoft
• Systems Center Operations Manager – Windows
Azure Management Pack RC

12. Demo
Web role with two instances demonstrating
various aspects of Windows Azure Diagnostics

13. Contact Information
• Neil Mackenzie
• Twitter: @mknz
• Blog: http://convective.wordpress.com/