Azure Application Gateway

Azure Application Gateway is a web traffic load balancer that enables you to manage traffic to your web applications. It works on application layer (OSI layer 7) and supports URL based routing. This integration helps in analyzing access patterns, tracking performance information for each instance, including total requests served, throughput in bytes, healthy and unhealthy backend instance count.

Log and metric types

For Azure Application Gateway, you can collect the following logs and metrics:

• Access log. These logs provide information on access patterns including the caller's IP, requested URL, response latency, return code, and bytes in and out.
• Performance log. These log captures performance information for each instance, including total requests served, throughput in bytes, total requests served, failed request count, and healthy and unhealthy backend instance count. The Performance log is available only for the v1 SKU. For the v2 SKU, use Metrics for performance data.
• Firewall log. You can use this log to view the requests that are logged through either detection or prevention mode of an application gateway that is configured with the web application firewall.

To learn more about the different resource log category types and schemas collected for Azure Application Gateway, refer to Azure documentation.

• Activity logs, provides insight into any subscription-level or management group level events that have occurred in the Azure. To learnmore, refer to Azure documentation.

• Platform Metrics for Azure Application Gateway. These metrics are available in Microsoft.Network/applicationGateways namespace. For more information on supported metrics in Azure Application Gateway v1 and Azure Application Gateway v2, refer to Azure documentation.

Setup

note

This app supports only Application Gateway V2 since Application Gateway V1 will soon be deprecated.

Azure service sends monitoring data to Azure Monitor, which can then stream data to Eventhub. Sumo Logic supports:

• Logs collection from Azure Monitor using our Azure Event Hubs source.
• Metrics collection using our HTTP Logs and Metrics source via Azure Functions deployed using the ARM template.

You must explicitly enable diagnostic settings for each Azure Application Gateway you want to monitor. You can forward logs to the same event hub provided they satisfy the limitations and permissions as described here.

When you configure the event hubs source or HTTP source, plan your source category to ease the querying process. A hierarchical approach allows you to make use of wildcards. For example: Azure/ApplicationGateway/Logs, Azure/ApplicationGateway/Metrics.

Configure field in field schema

1. Classic UI. In the main Sumo Logic menu, select Manage Data > Logs > Fields.
   New UI. In the top menu select Configuration, and then under Logs select Fields. You can also click the Go To... menu at the top of the screen and select Fields.
2. Search for the following fields:
   • tenant_name. This field is tagged at the collector level. You can get the tenant name using the instructions here.
   • location. The region to which the resource name belongs to.
   • subscription_id. ID associated with a subscription where the resource is present.
   • resource_group. The resource group name where the Azure resource is present.
   • provider_name. Azure resource provider name (for example, Microsoft.Network).
   • resource_type. Azure resource type (for example, storage accounts).
   • resource_name. The name of the resource (for example, storage account name).
   • service_type. Type of the service that can be accessed with a Azure resource.
   • service_name. Services that can be accessed with an Azure resource (for example, Azure SQL databases in Azure SQL Server).
3. Create the fields if they are not present. Refer to Manage fields.

Configure Field Extraction Rules

Create the following field extraction rules (FER) for Azure Storage by following the instructions in Create a Field Extraction Rule.

Azure location extraction FER

Rule Name: AzureLocationExtractionFER
Applied at: Ingest Time
Scope (Specific Data): tenant_name=*

Parse Expression

json "location", "properties.resourceLocation", "properties.region" as location, resourceLocation, service_region nodrop
| replace(toLowerCase(resourceLocation), " ", "") as resourceLocation
| if (!isBlank(resourceLocation), resourceLocation, location) as location
| if (!isBlank(service_region), service_region, location) as location 
| if (isBlank(location), "global", location) as location
| fields location

Resource ID extraction FER

Rule Name: AzureResourceIdExtractionFER
Applied at: Ingest Time
Scope (Specific Data): tenant_name=*

Parse Expression

json "resourceId", "ResourceId" as resourceId1, resourceId2 nodrop
| if (isBlank(resourceId1), resourceId2, resourceId1) as resourceId
| toUpperCase(resourceId) as resourceId
| parse regex field=resourceId "/SUBSCRIPTIONS/(?<subscription_id>[^/]+)" nodrop
| parse field=resourceId "/RESOURCEGROUPS/*/" as resource_group nodrop
| parse regex field=resourceId "/PROVIDERS/(?<provider_name>[^/]+)" nodrop
| parse regex field=resourceId "/PROVIDERS/[^/]+(?:/LOCATIONS/[^/]+)?/(?<resource_type>[^/]+)/(?<resource_name>.+)" nodrop
| parse regex field=resource_name "(?<parent_resource_name>[^/]+)(?:/PROVIDERS/[^/]+)?/(?<service_type>[^/]+)/?(?<service_name>.+)" nodrop
| if (isBlank(parent_resource_name), resource_name, parent_resource_name) as resource_name
| fields subscription_id, location, provider_name, resource_group, resource_type, resource_name, service_type, service_name

Configure metric rules

Create the following metrics rules by following the instructions in Create a metrics rule.

Azure observability metadata extraction application gateway level

Rule Name: AzureObservabilityMetadataExtractionAppGatewayLevel

Metric match expression

resourceId=/SUBSCRIPTIONS/*/RESOURCEGROUPS/*/PROVIDERS/*/APPLICATIONGATEWAYS/* tenant_name=*

Fields extracted	Metric rule
subscription_id	$resourceId._1
resource_group	$resourceId._2
provider_name	$resourceId._3
resource_type	APPLICATIONGATEWAYS
resource_name	$resourceId._4

Configure metrics collection

In this section, you will configure a pipeline for shipping metrics from Azure Monitor to an Event Hub, on to an Azure Function, and finally to an HTTP Source on a hosted collector in Sumo Logic.

1. Create hosted collector and tag tenant_name field.
   
2. Configure an HTTP Source.
3. Configure and deploy the ARM Template.
4. Export metrics to Event Hub. Perform below steps for each Azure Application Gateway that you want to monitor.
   1. Choose Stream to an event hub as destination.
   2. Select AllMetrics.
   3. Use the Event hub namespace created by the ARM template in Step 2 above. You can create a new Event hub or use the one created by ARM template. You can use the default policy RootManageSharedAccessKey as the policy name.
      
5. Tag the location field in the source with right location value.
   

Configure logs collection

Diagnostic logs

In this section, you will configure a pipeline for shipping diagnostic logs from Azure Monitor to an Event Hub.

1. To set up the Azure Event Hubs source in Sumo Logic, refer to the Azure Event Hubs Source for Logs.
2. To create the diagnostic settings in Azure portal, refer to the Azure documentation. Perform the steps below for each Azure application gateway account that you want to monitor.
   1. Choose Stream to an event hub as the destination.
   2. Select allLogs.
   3. Use the Event Hub namespace and Event Hub name configured in the previous step in the destination details section. You can use the default policy RootManageSharedAccessKey as the policy name.
      
3. Tag the location field in the source with right location value.
   

note

WAF logs and metrics will be available for WAF V2 tier and only after a WAF Policy has been associated with application gateway. Refer to the azure docs for more information. Go to Settings -> Configuration to check your application gateway tier

Activity Logs

To collect activity logs, follow the instructions here. Do not perform this step in case you are already collecting activity logs for a subscription.

note

Since this source contains logs from multiple regions, make sure that you do not tag this source with the location tag.

Installing the Azure Application Gateway app

Now that you have set up data collection, install the Azure Application Gateway Sumo Logic app to use the pre-configured dashboards that provide visibility into your environment for real-time analysis of overall usage.

To install the app:

1. Select App Catalog.
2. In the Search Apps field, search for and then select your app.
3. Optionally, you can scroll down to preview the dashboards included with the app. Then, click Install App (sometimes this button says Add Integration).
4. Click Next.
5. Look for the dialog confirming that your app was installed successfully.
   

Once an app is installed, it will appear in your Personal folder or the folder that you specified. From here, you can share it with other users in your organization. Dashboard panels will automatically start to fill with data matching the time range query received since you created the panel. Results won't be available immediately, but within about 20 minutes, you'll see completed graphs and maps.

Viewing the Azure Application Gateway dashboards

All dashboards have a set of filters that you can apply to the entire dashboard. Use these filters to drill down and examine the data to a granular level.

• You can change the time range for a dashboard or panel by selecting a predefined interval from a drop-down list, choosing a recently used time range, or specifying custom dates and times. Learn more.
• You can use template variables to drill down and examine the data on a granular level. For more information, see Filtering Dashboards with Template Variables.
• Most Next-Gen apps allow you to provide the scope at the installation time and are comprised of a key (_sourceCategory by default) and a default value for this key. Based on your input, the app dashboards will be parameterized with a dashboard variable, allowing you to change the dataset queried by all panels. This eliminates the need to create multiple copies of the same dashboard with different queries.

Overview

The Azure Application Gateway - Overview dashboard provides details like requests by location, current capacity units, failed requests count, average new connections per second, throughput - average bytes per second, unhealthy host count, current connections, and connections/sec trends.

Administrative Operations

The Azure Application Gateway - Administrative Operations dashboard provides details like Changes, Read/Write/Delete specific changes, different operations used, top 10 operations that caused most errors, and most common errors.

Backend

The Azure Application Gateway - Backend dashboard provides insights like unhealthy host count, server response, backend pool details, healthy host count trend, unhealthy host count trend, chart by backend status code, and backend response status for 2xx, 3xx, 4xx, 5xx.

Billing

The Azure Application Gateway - Billing dashboard provides insights like current capacity units, fixed capacity units, variable capacity units, estimated billed capacity units trend, current capacity units trend, fixed billable capacity units trend, and variable capacity units trend.

Failures

The Azure Application Gateway - Failures dashboard provides insights like top 10 application gateways with error, top 10 backend pool names with errors, top 10 rule names with error, top 10 errors by error info, chart by error code and error info, and failed requests by user agent and HTTP method.

Health

The Azure Application Gateway - Health dashboard provides details like recent alerts, resource health incidents, recent resource health status by resource name, trend by event type, downtime by causes, trend of unavailable, degraded, and available.

Latency

The Azure Application Gateway - Latency dashboard provides insights into the application gateway total time, application gateway total time versus backend last byte response time, backend connect time versus backend first byte response time, and backend first byte response time versus backend last byte response time.

Performance

The Azure Application Gateway - Performance dashboard provides insights into the total request rate, failed request rate, application gateway details, average active connections, capacity units, capacity unit utilization, current connections trend, throughput trend, sent bytes, and received bytes.

Security and Policy

The Azure Application Gateway - Security and Policy dashboard provides details into the total security events, recent security events, total denied policy events, total success policy events, total failed policy events, total recommendation events, and recent recommendation events.

Traffic

The Azure Application Gateway - Traffic dashboard provides details into the requests by client IP location, total requests, failed requests, requests by TLS version, chart by HTTP status code, response status trends for 2xx, 3xx, 4xx, 5xx, and so on.

Upgrade/Downgrade the Azure Application Gateway app (optional)

To update the app, do the following:

1. Select App Catalog.
2. In the Search Apps field, search for and then select your app.
   Optionally, you can identify apps that can be upgraded in the Upgrade available section.
3. To upgrade the app, select Upgrade from the Manage dropdown.
   1. If the upgrade does not have any configuration or property changes, you will be redirected to the Preview & Done section.
   2. If the upgrade has any configuration or property changes, you will be redirected to Setup Data page.
      1. In the Configure section of your respective app, complete the following fields.
         • Key. Select either of these options for the data source.
           • Choose Source Category and select a source category from the list for Default Value.
           • Choose Custom and enter a custom metadata field. Insert its value in Default Value.
      2. Click Next. You will be redirected to the Preview & Done section.

Post-update

Your upgraded app will be installed in the Installed Apps folder, and dashboard panels will start to fill automatically.

note

See our Release Notes changelog for new updates in the app.

To revert the app to a previous version, do the following:

1. Select App Catalog.
2. In the Search Apps field, search for and then select your app.
3. To version down the app, select Revert to < previous version of your app > from the Manage dropdown.

Uninstalling the Azure Application Gateway app (optional)

To uninstall the app, do the following:

1. Select App Catalog.
2. In the 🔎 Search Apps field, run a search for your desired app, then select it.
3. Click Uninstall.

Troubleshooting

HTTP Logs and Metrics Source used by Azure Functions

To troubleshoot metrics collection, follow the instructions in Collect Metrics from Azure Monitor > Troubleshooting metrics collection.