how to monitor azure internal load balancer correctly balancing the traffic between VM

Vikram Poojary 5

Deepanshukatara-6769 11,000 Reputation points

2024-11-05T13:17:56.8566667+00:00
Hello Vikram , Welcome to MS Q&A

To monitor an Azure internal load balancer and ensure it is correctly balancing the traffic between VMs, you can follow these steps:

Enable Load Balancer Diagnostics

Enable diagnostics for your load balancer to collect metrics and logs. This can be done through the Azure portal or using Azure CLI.

Using Azure Portal:

Navigate to your load balancer in the Azure portal.

Under the "Monitoring" section, select "Diagnostics settings."

Click on "Add diagnostic setting."

Select the metrics and logs you want to collect, such as "AllMetrics" and "LoadBalancerAlertEvent."

Choose a destination for the logs (e.g., Log Analytics workspace, Storage account, or Event Hub).

Save the settings.

Using Azure CLI:

az monitor diagnostic

Monitor Load Balancer Metrics

Azure Load Balancer provides several metrics that you can monitor to ensure it is correctly balancing traffic. Some key metrics include:

DipAvailability: The availability of the load balancer's data path.

ByteCount: The number of bytes processed by the load balancer.

PacketCount: The number of packets processed by the load balancer.

SNATConnectionCount: The number of SNAT connections used by the load balancer.

You can view these metrics in the Azure portal under the "Metrics" section of your load balancer.

Set Up Alerts

Set up alerts to notify you when certain conditions are met, such as high traffic or low availability.

Using Azure Portal:

Navigate to your load balancer in the Azure portal.

Under the "Monitoring" section, select "Alerts."

Click on "New alert rule."

Define the conditions for the alert (e.g., when DipAvailability is below 99%).

Set up the action group to notify you (e.g., email, SMS, webhook).

Save the alert rule.

Using Azure CLI:

az monitor metrics alert create \

Analyze Logs and Metrics

Use Azure Monitor and Log Analytics to analyze the collected logs and metrics. You can create custom queries to gain insights into the load balancer's performance and traffic distribution.

Example Log Analytics Query:

AzureDiagnostics |

By following these steps, you can effectively monitor your Azure internal load balancer and ensure it is correctly balancing the traffic between VMs.

References:

Monitor Load Balancer data with Azure Monitor

Azure Load Balancer metrics

Create, view, and manage log alerts using Azure Monitor

Please let us know if any questions

Kindly accept if it helps

Thanks

Deepanshu

Deepanshukatara-6769 11,000

First point command

az monitor diagnostic-settings create \
  --resource /subscriptions/{subscription-id}/resourceGroups/{resource-group}/providers/Microsoft.Network/loadBalancers/{load-balancer-name} \
  --name MyDiagnosticSetting \
  --logs '[{"category": "LoadBalancerAlertEvent", "enabled": true}]' \
  --metrics '[{"category": "AllMetrics", "enabled": true}]' \
  --workspace {log-analytics-workspace-id}

Third point command

az monitor metrics alert create \
  --name DipAvailabilityAlert \
  --resource /subscriptions/{subscription-id}/resourceGroups/{resource-group}/providers/Microsoft.Network/loadBalancers/{load-balancer-name} \
  --condition "avg DipAvailability < 99" \
  --description "Alert when DipAvailability is below 99%" \
  --action-group {action-group-id}

Fourth point command

AzureDiagnostics
| where ResourceType == "LOADBALANCERS"
| summarize count() by bin(TimeGenerated, 1h), dipAvailability_s
| render timechart

Ganesh Patapati 1,745 Reputation points Microsoft Vendor

2024-11-05T16:17:32.9166667+00:00
Hi Vikram Poojary,

Greetings,

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I'm just checking in to see if you had a chance to view the comment made by Deepanshukatara-6769 in fixing the issue. Meanwhile, you can also read through the suggestions below to fix your issue.

Analyzing Load Balancer Traffic with VNet flow logsVirtual network flow logs are a feature of Azure Network Watcher that logs information about IP traffic flowing through a virtual network. Flow data from virtual network flow logs is sent to Azure Storage. From there, you can access the data and export it to any visualization tool, security information and event management (SIEM) solution, or intrusion detection system (IDS).

For general guidance on creating and managing virtual network flow logs, see Manage virtual network flow logs. Once you have created your virtual network flow logs, you can access the data on Log Analytics workspaces where you can also query and filter the data to identify traffic flowing through your Load Balancer. See Traffic analytics schema and data aggregation for more details on the virtual network flow logs schema.

You can also enable Traffic Analytics when you are creating your virtual network flow logs which provides insights and visualizations on the flow log data such as traffic distribution, traffic pattern, application ports utilized, and top talkers in your virtual network.

Hope this clarifies, please let me know Is your issue resolved or not?

Regards,

Ganesh
Ganesh Patapati 1,745 Reputation points Microsoft Vendor

2024-11-06T15:37:40.1366667+00:00
Hello Vikram Poojary,

Greetings

Just checking in to see if you have got a chance to see the answer posted by Deepanshukatara-6769 or mine in resolving the issue.

Hope this clarifies, please let me know Is your issue resolved or not?

Regards,

Ganesh
Vikram Poojary 5 Reputation points

2024-11-06T17:30:16.1+00:00

Thank you so much Ganesh for info, We are evaluating your input and accordingly I will confirm, allow me sometime
Ganesh Patapati 1,745 Reputation points Microsoft Vendor

2024-11-07T10:16:05.8333333+00:00
Hello Vikram Poojary,

I hope you are doing well!

Just checking in to see if you have got a chance to see answer posted by Deepanshukatara-6769 or mine in resolving the issue.

If you are still facing any further issues, please don't hesitate to reach out to us. We are happy to assist you.

Looking forward to your response and appreciate your time on this.

Thanks

Ganesh
ChaitanyaNaykodi-MSFT 26,536 Reputation points Microsoft Employee

2024-11-07T23:59:24.0033333+00:00

@Vikram Poojary

Thank you so much Ganesh for info, We are evaluating your input and accordingly I will confirm, allow me sometime

Sounds good thank you for letting us know!

If it helps you can also go through this tutorial for additional details on Vnet Flow logs.

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