Technical Tip: How to obtain old data of an SD-WAN Performance-SLA

In Fortinet SD-WAN, Performance SLAs are important to monitor SD-WAN members' status to adapt accordingly the FortiGate behavior.

For example, with a configured Performance SLA like this (FortiManager Performance SLA view):

Some users go to see the Performance SLA measures from the FortiGate in SD-WAN -> Performance SLA TAB:

From there is possible to see only the trend in a short period.

To see the graphs with the Performance SLA trend on a longer time range is necessary to enable the sdwan-monitor-history feature in the FortiManager, as explained here: Enabling SD-WAN monitoring history.

In FortiManager CLI:

config system admin setting

    set sdwan-monitor-history enable

Important notes:

1. Pay attention to the impact of this feature, as explained in the document mentioned before.
2. In case of upgrades to v7.4.7 or v7.6.3 or newer versions of a FortiManager with sdwan-monitor-history already enabled before the upgrade, it is necessary to manually upgrade the SD-WAN history database after the firmware upgrade, as explained in the section: 'To upgrade your SD-WAN history database to the log-based format' of the FortiManager v7.4.7 Administration Guide: Enabling SD-WAN Monitoring History
3. Being the size of the new SD-WAN history Database bigger than the older one, this may cause the FortiManager disks to fill up. After the upgrade, it is possible to verify the usage of disks by executing diagnose system print df -h.To check whether the disk space exhaustion is caused by the SD-WAN database, it is necessary to execute the diagnose sys disk usage /var -h, checking how many GB are used by the /var/rtm folder. 

Focusing on the data collected, there are 2 options to see the graphs of measures:

First option:

Going to: SD-WAN Manager -> Network -> Monitor and scrolling down, the last graph group is of active Performance SLAs:

It is possible to customize the graph interval (without the sdwan-monitor-history feature is possible to see only the last 10 minutes).

Second Option:

Add the SD-WAN widget in the ad hoc TAB, under the Dashboard TABs group of a single FortiGate managed.

Path of the Dashboard TAB group: Device Manager -> Device Group Select the Device.

How to add the widget:

Scrolling down on the new TAB:

Data shown in the graphs is very useful to verify if a 'random traffic slowness' problem, which is not ongoing during technicians' troubleshooting, is caused by SD-WAN members' bad performances.

Related documents:

SD-WAN Monitor history view

Performance SLA

FortiManager 7.6.0 CLI Reference