Network availability monitoring

Dynatrace Managed version 1.296+ ActiveGate version 1.295+

Network availability monitoring (NAM) allows you to monitor the availability of remote hosts or services over the network when an HTTP/HTTPS endpoint isn't available.

You can use NAM for infrastructure-related use cases or to deepen the root cause analysis for HTTP and browser monitors.

You can create synthetic network availability monitors of ICMP, TCP, or DNS type. To learn how to create NAM monitors, see Create NAM monitors.

NAM types

There are three types of network availability monitors.

  • ICMP—Sends pings with a configurable number of packets or size to validate if there's a network connection to the host or device. It also checks the quality of that connection.
  • TCP—Establishes a TCP connection to a particular port. It validates if a port is open and if it accepts TCP connections. It also checks if a host is available through the network.
  • DNS—Validates if a hostname can be resolved to an IP address.

To find out more about NAM types, see available script configuration properties.

Reporting

On-demand monitor execution

Monitor execution is possible via API. The retention period for data from monitor execution is 6 hours.

To display an overview of your monitor, select Network availability monitors in Synthetic Classic. You'll see a list of all your NAM monitors, select the monitor name to open the overview (reporting) page.

The default reporting pages consist of:

  • Metrics
  • Request metrics
  • TCP, ICMP or DNS metrics
  • Monitored hosts (these are only visible if your monitor has been defined with a filter expression)
  • Events

Metrics

In the Metrics section, you can see

  • a bar chart showing the number of monitor executions.
  • a line chart showing the average monitor execution time.
  • a line chart showing the average monitor availability.

For each of the above, you can select More to Show in data explorer, Create metric event, Pin to dashboard.

Request metrics

In the Request metrics section, you can see

  • a bar chart showing the average number of requests executions.
  • a line chart showing the average requests availability.

For each of the above, you can select More to Show in data explorer, Create metric event, Pin to dashboard.

TCP, ICMP and DNS metrics

In this section, you can see a chart showing one of the following metrics depending on your monitor type

  • TCP - showing a chart for the connection time by request.
  • ICMP - showing charts for success rate by request, packets sent by request, packets received by request and Round trip time by request.
  • DNS - showing a chart for the resolution time.

For each of the above, you can select More to Show in data explorer, Create metric event, Pin to dashboard.

Monitored hosts

This section shows a list of your monitored hosts. You can sort them by name. Selecting a particular hostname will show a detailed view of it in Hosts.

Events

This section shows a bar chart of events. If an outage is listed you need to select Expand row, to see its details.

Problems

Problems are created on the monitor level.

If your monitor

  1. If there's a problem with your monitor you'll see Problems under the monitor name. Select Problems, then select Go to Problems.
  2. In Problems, you'll see monitors affected by problems, where each problem consists of at least one of the follwoing
    • Affected steps—Expand the Step Id to see at least one of the following details request id, request type, failure reason and status message.
    • Affected requests—Expand the Request target you'll see request target address, request id, request type and failure reasons.
    • Affected locations.
    • Date of first failed execution.

Limitations

There are certain limitations when using network availability monitors. You can find out more about them below.

Number of requests

The maximum number of network activities executed per network availability monitor is 1,000. Network activity is a single DNS request, single TCP request, or single ICMP packet. Dynatrace may use multiple packets within a single ICMP request, if configured.

If a monitor uses a target filter, it might not be possible to precisely predict the number of requests in advance of execution (for example, when monitoring an entire host group or a subnet with a wide IP range). In such cases, the limit is applied when the target filter is resolved before the monitor's execution into the actual list of addresses.

The number of requests depends on the number of hosts matching the filter. For example, when monitoring an entire host group or filtering the monitored hosts using a subnet with a wide IP range.

Number of monitors

You can have up to 5,000 NAM monitors per environment. Other types of monitors don't contribute to this limit.

Deployment type

Network availability monitors are supported only on private Synthetic locations.

Network availability monitors are supported on containerized Synthetic-enabled ActiveGate deployments, but additional permissions are required for ICMP tests.

To enable ICMP request type for NAM execution

  1. In Settings, select and expand Web and mobile monitoring.
  2. In the Web and mobile monitoring section, select Private Synthetic Locations.
  3. Select Add Kubernetes location.
  4. Configure your location and make sure to turn on Enable ICMP request type for Network Availability Monitors execution.

ICMP monitors use the ping executable, which requires the CAP_NET_RAW capability set for the container executing the requests (synthetic-vuc). Additionally, the allowPrivilegeEscalation property of securityContext for this container has to be set to true, because the process that launches the ping executable doesn't have the required privileges set by default.

The entire securityContext for the synthetic-vuc container with enabled network availability monitors should look as follows.

securityContext:
  readOnlyRootFilesystem: true
  privileged: false
  allowPrivilegeEscalation: true
  runAsNonRoot: true
  capabilities:
    drop: ["all"]
    add: ["NET_RAW"]