Choose a city-networks maximum limit
In addition to setting a traffic percentage for your monitor in Amazon CloudWatch Internet Monitor, you can also set a maximum limit for the number of city-networks monitored. This section describes how the city-networks limit can help you manage billing costs, and provides information and an example to help you determine a limit to set, if you choose to set one.
Internet Monitor can monitor traffic for some or all of the locations where clients access your AWS application resources. You can set a monitoring limit for the number of city-networks, that is, the client locations and the ASNs (typically internet service providers) that clients access your application through.
You choose a percentage of application traffic to monitor when you create your monitor. The default percentage is 100%. You can update the percentage at any time, by editing the monitor.
The maximum limit that you set for the number of city-networks helps to make sure that your bill is predictable. For more information, see
Amazon CloudWatch Pricing
To update your monitor and change the maximum city-networks limit, see Edit a monitor in Internet Monitor.
How billing works with city-networks maximum limits
Setting a maximum limit for the number of city-networks monitored can help prevent unexpected costs in your bill. This is useful, for example, if your traffic patterns vary widely. Billing costs increase for each city-network that is monitored after the first 100 city-networks, which are included (across all monitors per account). If you set a city-networks maximum limit, it caps the number of city-networks that Internet Monitor monitors for your application, regardless of the percentage of traffic that you choose to monitor.
You only pay for the number of city-networks that are actually monitored. The city-network maximum limit that you choose lets you set a cap on the total that can be included when Internet Monitor monitors traffic with your monitor. You can change the maximum limit at any time by editing your monitor.
To explore options, on the Pricing calculator for CloudWatch
How to choose a city-networks maximum limit
Optionally, you can set a city-networks maximum limit. To help you decide on a maximum limit that you might want to select, consider how much traffic you want to monitor for your application. Be aware that if you choose 100% for the traffic percentage to monitor for your monitor, and then specify a city-networks maximum limit, depending on the limit that you choose, you might not monitor 100% of your application traffic. The city-networks maximum that you set takes precedence over the traffic percentage to monitor that you set.
To view how the percentage of traffic to monitor that you choose affects the number of city-monitors that are included for your application monitoring, which can help you decide whether to set a city-networks maximum limit, follow the steps in View the number of city-networks monitored at different traffic percentage settings.
To explore your options in more detail, you can use Internet Monitor metrics, as described in the following examples. These examples show how to select a maximum city-networks limit that is best for you, depending on the breadth of application internet traffic coverage you want. Using the queries for Internet Monitor metrics in CloudWatch Metrics can help you understand more about your application internet traffic coverage.
Example of determining a city-networks maximum limit
As an example, say that you've set a monitoring maximum limit of 100 city-networks and that your application is accessed by clients across 2637 city-networks. In CloudWatch Metrics, you'd see the following Internet Monitor metrics returned:
CityNetworksMonitored 100 TrafficMonitoredPercent 12.5 CityNetworksFor90PercentTraffic 2143 CityNetworksFor100PercentTraffic 2637
From this example, you can see that you're currently monitoring 12.5% of your internet traffic, with the maximum limit set to 100 city-networks.
If you want to monitor 90% of your traffic, the next metric provides information about that: CityNetworksFor90PercentTraffic
indicates that you would need to monitor 2,143 city-networks for 90% coverage. To do that, you would update your monitor and
set the maximum city-networks limit to 2,143.
Similarly, say you'd like to have 100% internet traffic monitoring for your application. The next metric,
CityNetworksFor100PercentTraffic, indicates that to do this, you should update your monitor to set the maximum city-networks limit to
2,637.
If you now set the maximum to 5,000 city-networks, since that's greater than 2,637, you see the following metrics returned:
CityNetworksMonitored 2637 TrafficMonitoredPercent 100 CityNetworksFor90PercentTraffic 2143 CityNetworksFor100PercentTraffic 2637
From these metrics, you can see that with the higher limit, you monitor all 2,637 city-networks, which is 100% of your internet traffic.
