CloudWatch metrics for your Network Load Balancer
Elastic Load Balancing publishes data points to Amazon CloudWatch for your load balancers and your targets. CloudWatch enables you to retrieve statistics about those data points as an ordered set of time-series data, known as metrics. Think of a metric as a variable to monitor, and the data points as the values of that variable over time. For example, you can monitor the total number of healthy targets for a load balancer over a specified time period. Each data point has an associated time stamp and an optional unit of measurement.
You can use metrics to verify that your system is performing as expected. For example, you can create a CloudWatch alarm to monitor a specified metric and initiate an action (such as sending a notification to an email address) if the metric goes outside what you consider an acceptable range.
Elastic Load Balancing reports metrics to CloudWatch only when requests are flowing through the load balancer. If there are requests flowing through the load balancer, Elastic Load Balancing measures and sends its metrics in 60-second intervals. If there are no requests flowing through the load balancer or no data for a metric, the metric is not reported. For Network Load Balancers with security groups, traffic rejected by the security groups is not captured in the CloudWatch metrics.
For more information, see the Amazon CloudWatch User Guide.
Contents
Network Load Balancer metrics
The AWS/NetworkELB namespace includes the following metrics for flows.
| Metric | Description |
|---|---|
ActiveFlowCount |
The total number of concurrent flows (or connections) from clients to targets. This metric includes connections in the SYN_SENT and ESTABLISHED states. TCP connections are not terminated at the load balancer, so a client opening a TCP connection to a target counts as a single flow. Reporting criteria: Always reported. Statistics: The most useful
statistics are Dimensions
|
ActiveFlowCount_TCP |
The total number of concurrent TCP flows (or connections) from clients to targets. This metric includes connections in the SYN_SENT and ESTABLISHED state. TCP connections are not terminated at the load balancer, so a client opening a TCP connection to a target counts as a single flow. Reporting criteria: There is a nonzero value Statistics: The most useful
statistics are Dimensions
|
ActiveFlowCount_TLS |
The total number of concurrent TLS flows (or connections) from clients to targets. This metric includes connections in the SYN_SENT and ESTABLISHED state. Reporting criteria: There is a nonzero value. Statistics: The most useful
statistics are Dimensions
|
ActiveFlowCount_UDP |
The total number of concurrent UDP flows (or connections) from clients to targets. Reporting criteria: There is a nonzero value. Statistics: The most useful
statistics are Dimensions
|
NewFlowCount |
The total number of new flows (or connections) established from clients to targets in the time period. Reporting criteria: Always reported. Statistics: The most useful
statistic is Dimensions
|
NewFlowCount_TCP |
The total number of new TCP flows (or connections) established from clients to targets in the time period. Reporting criteria: There is a nonzero value. Statistics: The most useful
statistic is Dimensions
|
NewFlowCount_TLS |
The total number of new TLS flows (or connections) established from clients to targets in the time period. Reporting criteria: There is a nonzero value. Statistics: The most useful
statistic is Dimensions
|
NewFlowCount_UDP |
The total number of new UDP flows (or connections) established from clients to targets in the time period. Reporting criteria: There is a nonzero value. Statistics: The most useful
statistic is Dimensions
|
NewFlowCount_QUIC |
The total number of UDP datagrams that required a routing decision in the time period. Reporting criteria: There is a nonzero value. Statistics: The most useful
statistic is Dimensions
|
RejectedFlowCount |
The total number of flows (or connections) rejected by the load balancer. Reporting criteria: Always reported. Statistics: The most useful
statistics are Dimensions
|
RejectedFlowCount_TCP |
The number of TCP flows (or connections) rejected by the load balancer. Reporting criteria: There is a nonzero value. Statistics: The most useful statistic is Dimensions
|
UnhealthyRoutingFlowCount |
The number of flows (or connections) that are routed using the routing failover action (fail open). This metric is not supported for TLS listeners. Reporting criteria: There is a nonzero value. Statistics: The most useful
statistic is |
QUIC_Unknown_Server_ID_Packet_Drop_Count |
The number of UDP datagrams dropped which contain a server ID not associated with a target in the Network Load Balancer. Reporting criteria: Reported only for QUIC listeners. Statistics: The most useful
statistic is Dimensions
|
The AWS/NetworkELB namespace includes the following metrics for throughput.
| Metric | Description |
|---|---|
ProcessedBytes |
The total number of bytes processed by the load balancer, including TCP/IP headers. This count includes traffic to and from targets, minus health check traffic. |