Monitoring load balancer data reference

Article
05/08/2023

See Monitoring Load Balancer for details on collecting and analyzing monitoring data for Load Balancer.

Metrics

Load balancer metrics

Metric	Resource type	Description	Recommended aggregation
Data path availability	Public and internal load balancer	Standard Load Balancer continuously exercises the data path from within a region to the load balancer front end, all the way to the SDN stack that supports your VM. As long as healthy instances remain, the measurement follows the same path as your application's load-balanced traffic. The data path that your customer's use is also validated. The measurement is invisible to your application and doesn't interfere with other operations.	Average
Health probe status	Public and internal load balancer	Standard Load Balancer uses a distributed health-probing service that monitors your application endpoint's health according to your configuration settings. This metric provides an aggregate or per-endpoint filtered view of each instance endpoint in the load balancer pool. You can see how Load Balancer views the health of your application, as indicated by your health probe configuration.	Average
SYN (synchronize) count	Public and internal load balancer	Standard Load Balancer uses a distributed health-probing service that monitors your application endpoint's health according to your configuration settings. This metric provides an aggregate or per-endpoint filtered view of each instance endpoint in the load balancer pool. You can see how Load Balancer views the health of your application, as indicated by your health probe configuration.	Average
SNAT connection count	Public load balancer	Standard Load Balancer reports the number of outbound flows that are masqueraded to the Public IP address front end. Source network address translation (SNAT) ports are an exhaustible resource. This metric can give an indication of how heavily your application is relying on SNAT for outbound originated flows. Counters for successful and failed outbound SNAT flows are reported and can be used to troubleshoot and understand the health of your outbound flows.	Sum
Allocated SNAT ports	Public load balancer	Standard Load Balancer reports the number of SNAT ports allocated per backend instance.	Average
Used SNAT ports	Public load balancer	Standard Load Balancer reports the number of SNAT ports that are utilized per backend instance.	Average
Byte count	Public and internal load balancer	Standard Load Balancer reports the data processed per front end. You may notice that the bytes aren't distributed equally across the backend instances. This is expected as Azure's Load Balancer algorithm is based on flows.	Sum
Packet count	Public and internal load balancer	Standard Load Balancer reports the packets processed per front end.	Sum

For more information, see a list of all platform metrics supported in Azure Monitor for load balancer.

Metric dimensions

For more information on what metric dimensions are, see Multi-dimensional metrics.

Load Balancer has the following dimensions associated with its metrics.

Dimension Name	Description
Frontend IP	The frontend IP address of the relevant load balancing rule(s)
Frontend Port	The frontend port of the relevant load balancing rule(s)
Backend IP	The backend IP address of the relevant load balancing rule(s)
Backend Port	The backend port of the relevant load balancing rule(s)
Protocol Type	The protocol of the relevant load balancing rule, this can be TCP or UDP
Direction	The direction traffic is flowing. This can be inbound or outbound.
Connection state	The state of SNAT connection, this can be pending, successful, or failed

Resource logs

Resource logs are currently unsupported by Azure Load Balancer

Azure Monitor logs tables

Diagnostics tables

Diagnostics tables are currently unsupported by Azure Load Balancer.

Activity log

The following table lists the operations related to Load Balancer that may be created in the Activity log.

Operation	Description
Microsoft.Network/loadBalancers/read	Gets a load balancer definition
Microsoft.Network/loadBalancers/write	Creates a load balancer or updates an existing load balancer
Microsoft.Network/loadBalancers/delete	Deletes a load balancer
Microsoft.Network/loadBalancers/backendAddressPools/queryInboundNatRulePortMapping/action	Query inbound Nat rule port mapping.
Microsoft.Network/loadBalancers/backendAddressPools/read	Gets a load balancer backend address pool definition
Microsoft.Network/loadBalancers/backendAddressPools/write	Creates a load balancer backend address pool or updates an existing load balancer backend address pool
Microsoft.Network/loadBalancers/backendAddressPools/delete	Deletes a load balancer backend address pool
Microsoft.Network/loadBalancers/backendAddressPools/join/action	Joins a load balancer backend address pool. Not Alertable.
Microsoft.Network/loadBalancers/backendAddressPools/backendPoolAddresses/read	Lists the backend addresses of the Load Balancer backend address pool
Microsoft.Network/loadBalancers/frontendIPConfigurations/read	Gets a load balancer frontend IP configuration definition
Microsoft.Network/loadBalancers/frontendIPConfigurations/join/action	Joins a Load Balancer Frontend IP Configuration. Not alertable.
Microsoft.Network/loadBalancers/inboundNatPools/read	Gets a load balancer inbound nat pool definition
Microsoft.Network/loadBalancers/inboundNatPools/join/action	Joins a load balancer inbound NAT pool. Not alertable.
Microsoft.Network/loadBalancers/inboundNatRules/read	Gets a load balancer inbound nat rule definition
Microsoft.Network/loadBalancers/inboundNatRules/write	Creates a load balancer inbound nat rule or updates an existing load balancer inbound nat rule
Microsoft.Network/loadBalancers/inboundNatRules/delete	Deletes a load balancer inbound nat rule
Microsoft.Network/loadBalancers/inboundNatRules/join/action	Joins a load balancer inbound nat rule. Not Alertable.
Microsoft.Network/loadBalancers/loadBalancingRules/read	Gets a load balancer load balancing rule definition
Microsoft.Network/loadBalancers/networkInterfaces/read	Gets references to all the network interfaces under a load balancer
Microsoft.Network/loadBalancers/outboundRules/read	Gets a load balancer outbound rule definition
Microsoft.Network/loadBalancers/probes/read	Gets a load balancer probe
Microsoft.Network/loadBalancers/probes/join/action	Allows using probes of a load balancer. For example, with this permission healthProbe property of virtual machine scale set can reference the probe. Not alertable.
Microsoft.Network/loadBalancers/virtualMachines/read	Gets references to all the virtual machines under a load balancer

For more information on the schema of Activity Log entries, see Activity Log schema.