# Description of ALB Monitored Items

When your ALB encounters network problems such as request timeouts and traffic rate limiting, or if you want to gain a deeper understanding of the load and performance of ALB, you can monitor key indicators of ALB to achieve real-time tracking, accurate analysis, and rapid location of issues, thereby ensuring stable and efficient operation of the service.

# Instance Monitoring (Intranet)

| Monitored Items             | Description                                        |
| :----------------------------- | :-------------------------------------------------- |
| Inbound Intranet Bandwidth Monitoring | Average bandwidth used by the client to access the load balancer instance through the intranet |
| Outbound Intranet Bandwidth     | Average bandwidth used by the load balancer to access the intranet.             |
| Outbound Intranet Packet Count   | The number of packets that the load balancer sends to the client through the intranet.   |
| Inbound Intranet Packet Count   | The number of packets that the client sends to the load balancer through the intranet.   |

# Instance Monitoring (Internet)

| Monitored Items         | Description                                             |
| :------------------------ | :------------------------------------------------------- |
| Network Ingress       | Average bandwidth used by the client to access the load balancer through the internet.       |
| Network Egress       | The average bandwidth used by the load balancer to access the internet.                 |
| Inbound Bandwidth Utilization | Bandwidth usage rate of the client accessing the load balancer through the internet.     |
| Outbound Bandwidth Utilization | Bandwidth usage rate of the load balancer when accessing the internet.               |
| Peak Outbound Bandwidth   | Peak bandwidth of the load balancer when accessing the internet.                 |
| Peak Inbound Bandwidth   | Peak bandwidth of the client when accessing the load balancer through the internet.       |
| Outbound Packet Count     | The number of packets that the load balancer sends to the client through the internet.       |
| Inbound Packet Count     | The number of packets that the client sends to the load balancer through the internet.       |
| Outbound Packet Loss     | Packets discarded by the load balancer when accessing the internet.                 |
| Inbound Packet Loss     | Packets discarded by the client when accessing the load balancer through the internet.       |
| Outbound Packet Loss Percentage | The percentage of packets discarded by the load balancer to the total outbound packets |
| Inbound Packet Loss Percentage | The percentage of packets discarded by the client to the total outbound packets |

# Listener Monitoring

| Monitored Items           | Description                                                   |
| :----------------------- | :-------------------------------------------------------------- |
| Listener Connection Count  | The number of active connections from clients to the listener                         |
| New Connection Count       | The number of new connections from clients to the listener.                       |
| HTTP 2XX         | The number of 2xx status codes returned by the load balancer                          |
| HTTP 3XX         | The number of 3xx status codes returned by the load balancer                          |
| HTTP 4XX         | The number of 4xx status codes returned by the load balancer                          |
| HTTP 5XX         | The number of 5xx status codes returned by the load balancer                          |
| Other HTTP Status Codes   | The number of status codes returned by the load balancer other than 5xx, 3xx, 2xx and 4xx  |
| Requests Per Second       | The number of requests to the load balancer.                                     |
| Node Failure Percentage   | The percentage of the number of abnormal listeners found in the health check to the number of all nodes             |
| Average Request Time     | Average request time of the load balancer                                 |
| Average Backend Response Time | Average response time of the backend service nodes of the load balancer                     |