# Getting the Metrics

You can view the lag metrics either via your Application Insights instance or via the connected Log Analytics Workspace

In your Application Insights instance you can see the lag metrics in the Metrics section.

Select the metrics as shown in this screenshot:

You can either select the metric that tracks the total lag across all partitions or the one that tracks individual partitions:

If you have multiple Event Hubs, apply splitting to see the lags of the individual Event Hubs:

To see the lag metrics in your Log Analytics Workspace, go to Logs. Then you can query for the metrics:

Here is an example using Simple Mode:

The name of the metric is EventHubLag. The value of the metric is the number of messages that have not yet been processed in the context of a certain event hub and consumer group. The values are already summed up over all partitions of the Event Hub. This level of detail is usually sufficient, as the overall lag across all partitions is most relevant.

Custom dimensions of this metric are:

• EventHubNamespace: Name of the Event Hub Namespace.
• EventHub: Name of the Event Hub.
• ConsumerGroup: Name of the consumer group.

The name of the metric is EventHubPartitionLag. The value of the metric is the number of messages that have not yet been processed in the context of a certain event hub, partition and consumer group.

Custom dimensions of this metric are:

• EventHubNamespace: Name of the Event Hub Namespace.
• EventHub: Name of the Event Hub.
• ConsumerGroup: Name of the consumer group.
• PartitionId: Numerical identifier of the partition. If you have 4 partitions, values are 0, 1, 2 and 3.

This metric provides maximum flexibility as it includes information about partitions.

The lag for a particular Event Hub and Consumer Group can be extracted using the following Log Analytics / KQL query:

customMetrics
| where name == 'EventHubPartitionLag'
| extend eventHub=tostring(customDimensions['EventHub'])
| extend consumerGroup=tostring(customDimensions['ConsumerGroup'])
| extend partitionId=tostring(customDimensions['PartitionId'])
| where consumerGroup == '$Default' and eventHub == 'example-event-hub'
| summarize lag=sum(value) by bin(timestamp, 1m)
| order by timestamp desc