Description
This article describes the use of the performance statistics logs and how to adjust their frequency or disable it when needed.
Solution
FortiOS has a feature that creates a periodic log entry with general information about the performance of the unit.
It includes information about the CPU and memory usage, together with the concurrent session count and setup rate. See the sample below:
itime=2020-09-01 11:13:06 vd=root bandwidth=13/16 totalsession=53 disk=1 dstepid=3 devid=FGVM04TM20001209 disklograte=0 logdesc=System performance statistics msg=Performance statistics: average CPU: 0, memory: 48, concurrent sessions: 53, setup-rate: 0 idseq=267453240667275345 type=event eventtime=1598951586 mem=48 dtime=2020-09-01 11:13:06 devname=FGT-VM-HEL setuprate=0 dsteuid=0 itime_t=1598951586 euid=3 fazlograte=20 date=2020-09-01 level=notice epid=3 logid=0100040704 subtype=system time=11:13:06 action=perf-stats cpu=0
Features:
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What It Monitors:
- CPU Usage: Understand how much of the CPU resource is being utilized.
- Memory Usage: Gauge memory consumption over time.
- Concurrent Sessions: Provides insights into the number of simultaneous sessions the unit is handling.
- Setup-Rate: Measures the rate at which new sessions are being set up.
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Value in Troubleshooting:
- Being able to view historical data can help in correlating certain performance issues to specific events or changes.
- Gives a granular understanding of when and how resource consumption peaks or drops.
This regular report can be very useful when troubleshooting changes in the behavior of the units in terms of resource usage because it provides records to track those changes over time.
However, in some situations this feature is unwanted because of the frequency of these reports so there is a configuration parameter to be modified in those cases.
The option is available just from CLI and it is as follows:
config system global
set sys-perf-log-interval <0-15>
end
where:
0 <----- Disabled
1-15 <----- Time in minutes between logging. 5 is the default value.
Best Practices:
-
Monitoring Frequency: While it is tempting to log everything, consider the impact on system performance and storage. Adjust the frequency based on the criticality of monitoring needs.
-
External Storage: Leveraging solutions like FortiAnalyzer can provide a comprehensive view over a more extended period, helpful in trend analysis.
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Alerts and Notifications: Consider setting up alerts for abnormal behavior. Sudden spikes in CPU or memory usage might be indicative of potential issues.
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Data Correlation: When analyzing the logs, try to correlate data spikes or abnormalities with other events or changes in the network. This holistic view can help pinpoint issues faster.
Note:
Performance statistics are not logged to disk. It is showing on memory. Performance statistics can be received by a syslog server or by FortiAnalyzer.
For FortiGates with VDOM enabled, the per-stats are logged in the root VDOM only.
The Performance Statistics Logs are a crucial tool in the arsenal of FortiGate administrators, allowing for proactive monitoring and faster troubleshooting. Properly configured, it will provide invaluable insights without overwhelming system resources.
Related documents:
Log and Report
Technical Note: No system performance statistics logs
