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Get resource changes

  • Article

Resources change through the course of daily use, reconfiguration, and even redeployment. Most change is by design, but sometimes it isn't. You can:

  • Find when changes were detected on an Azure Resource Manager property.
  • View property change details.
  • Query changes at scale across your subscriptions, management group, or tenant.

In this article, you learn:

  • What the payload JSON looks like.
  • How to query resource changes through Resource Graph using either the CLI, PowerShell, or the Azure portal.
  • Query examples and best practices for querying resource changes.

Prerequisites

Understand change event properties

When a resource is created, updated, or deleted, a new change resource (Microsoft.Resources/changes) is created to extend the modified resource and represent the changed properties. Change records should be available in less than five minutes. The following example JSON payload demonstrates the change resource properties:

{
  "targetResourceId": "/subscriptions/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/resourceGroups/myResourceGroup/providers/microsoft.compute/virtualmachines/myVM",
  "targetResourceType": "microsoft.compute/virtualmachines",
  "changeType": "Update",
  "changeAttributes": {
    "previousResourceSnapshotId": "08584889383111245807_37592049-3996-ece7-c583-3008aef9e0e1_4043682982_1712668574",
    "newResourceSnapshotId": "08584889377081305807_38788020-eeee-ffff-028f-6121bdac9cfe_4213468768_1712669177",
    "correlationId": "04ff69b3-e162-4583-9cd7-1a14a1ec2c61",
    "changedByType": "User",
    "changesCount": 2,
    "clientType": "ARM Template",
    "changedBy": "john@contoso.com",
    "operation": "microsoft.compute/virtualmachines/write",
    "timestamp": "2024-04-09T13:26:17.347+00:00"
  },
  "changes": {
    "properties.provisioningState": {
      "newValue": "Succeeded",
      "previousValue": "Updating",
      "changeCategory": "System",
      "propertyChangeType": "Update",
      "isTruncated": "true"
    },
    "tags.key1": {
      "newValue": "NewTagValue",
      "previousValue": "null",
      "changeCategory": "User",
      "propertyChangeType": "Insert"
    }
  }
}

See the full reference guide for change resource properties.

Run a query

Try out a tenant-based Resource Graph query of the resourcechanges table. The query returns the first five most recent Azure resource changes with the change time, change type, target resource ID, target resource type, and change details of each change record.

# Login first with az login if not using Cloud Shell
 
# Run Azure Resource Graph query
az graph query -q 'resourcechanges | project properties.changeAttributes.timestamp, properties.changeType, properties.targetResourceId, properties.targetResourceType, properties.changes | limit 5'

You can update this query to specify a more user-friendly column name for the timestamp property.

# Run Azure Resource Graph query with 'extend'
az graph query -q 'resourcechanges | extend changeTime=todatetime(properties.changeAttributes.timestamp) | project changeTime, properties.changeType, properties.targetResourceId, properties.targetResourceType, properties.changes | limit 5'

To limit query results to the most recent changes, update the query to order by the user-defined changeTime property.

# Run Azure Resource Graph query with 'order by'
az graph query -q 'resourcechanges | extend changeTime=todatetime(properties.changeAttributes.timestamp) | project changeTime, properties.changeType, properties.targetResourceId, properties.targetResourceType, properties.changes | order by changeTime desc | limit 5'

You can also query by management group or subscription with the -ManagementGroup or -Subscription parameters, respectively.

Note

If the query does not return results from a subscription you already have access to, then the Search-AzGraph PowerShell cmdlet defaults to subscriptions in the default context.

Resource Graph Explorer also provides a clean interface for converting the results of some queries into a chart that can be pinned to an Azure dashboard.

Query resource changes

With Resource Graph, you can query either the resourcechanges, resourcecontainerchanges, or healthresourcechanges tables to filter or sort by any of the change resource properties. The following examples query the resourcechanges table, but can also be applied to the resourcecontainerchanges or healthresourcechanges table.

Note

Learn more about the healthresourcechanges data in the Project Flash documentation.

Examples

Before querying and analyzing changes in your resources, review the following best practices.

  • Query for change events during a specific window of time and evaluate the change details.
    • This query works best during incident management to understand potentially related changes.
  • Keep an up-to-date Configuration Management Database (CMDB).
    • Instead of refreshing all resources and their full property sets on a scheduled frequency, you'll only receive their changes.
  • Understand what other properties may have been changed when a resource changes "compliance state".
    • Evaluation of these extra properties can provide insights into other properties that may need to be managed via an Azure Policy definition.
  • The order of query commands is important. In the following examples, the order by must come before the limit command.
    • The order by command orders the query results by the change time.
    • The limit command then limits the ordered results to ensure that you get the five most recent results.

All changes in the past 24-hour period

resourcechanges 
| extend changeTime = todatetime(properties.changeAttributes.timestamp), targetResourceId = tostring(properties.targetResourceId),
changeType = tostring(properties.changeType), correlationId = properties.changeAttributes.correlationId, 
changedProperties = properties.changes, changeCount = properties.changeAttributes.changesCount
| where changeTime > ago(1d)
| order by changeTime desc
| project changeTime, targetResourceId, changeType, correlationId, changeCount, changedProperties

Resources deleted in a specific resource group

resourcechanges
| where resourceGroup == "myResourceGroup"
| extend changeTime = todatetime(properties.changeAttributes.timestamp), targetResourceId = tostring(properties.targetResourceId),
changeType = tostring(properties.changeType), correlationId = properties.changeAttributes.correlationId
| where changeType == "Delete"
| order by changeTime desc
| project changeTime, resourceGroup, targetResourceId, changeType, correlationId

Changes to a specific property value

resourcechanges
| extend provisioningStateChange = properties.changes["properties.provisioningState"], changeTime = todatetime(properties.changeAttributes.timestamp), targetResourceId = tostring(properties.targetResourceId), changeType = tostring(properties.changeType)
| where isnotempty(provisioningStateChange)and provisioningStateChange.newValue == "Succeeded"
| order by changeTime desc
| project changeTime, targetResourceId, changeType, provisioningStateChange.previousValue, provisioningStateChange.newValue

Latest resource changes for resources created in the last seven days

resourcechanges
| extend targetResourceId = tostring(properties.targetResourceId), changeType = tostring(properties.changeType), changeTime = todatetime(properties.changeAttributes.timestamp)
| where changeTime > ago(7d) and changeType == "Create"
| project  targetResourceId, changeType, changeTime
| join ( Resources | extend targetResourceId=id) on targetResourceId
| order by changeTime desc
| project changeTime, changeType, id, resourceGroup, type, properties

Changes in virtual machine size 

resourcechanges
|extend vmSize = properties.changes["properties.hardwareProfile.vmSize"], changeTime = todatetime(properties.changeAttributes.timestamp), targetResourceId = tostring(properties.targetResourceId), changeType = tostring(properties.changeType) 
| where isnotempty(vmSize) 
| order by changeTime desc 
| project changeTime, targetResourceId, changeType, properties.changes, previousSize = vmSize.previousValue, newSize = vmSize.newValue

Count of changes by change type and subscription name

resourcechanges  
|extend changeType = tostring(properties.changeType), changeTime = todatetime(properties.changeAttributes.timestamp), targetResourceType=tostring(properties.targetResourceType)  
| summarize count() by changeType, subscriptionId 
| join (resourcecontainers | where type=='microsoft.resources/subscriptions' | project SubscriptionName=name, subscriptionId) on subscriptionId 
| project-away subscriptionId, subscriptionId1
| order by count_ desc  

Latest resource changes for resources created with a certain tag

resourcechanges 
|extend targetResourceId = tostring(properties.targetResourceId), changeType = tostring(properties.changeType), createTime = todatetime(properties.changeAttributes.timestamp) 
| where createTime > ago(7d) and changeType == "Create" or changeType == "Update" or changeType == "Delete"
| project  targetResourceId, changeType, createTime 
| join ( resources | extend targetResourceId=id) on targetResourceId
| where tags ['Environment'] =~ 'prod' 
| order by createTime desc 
| project createTime, id, resourceGroup, type

Next steps

View resource changes in the portal