Working With Performance Co-Pilot

4 Working With Performance Co-Pilot

WARNING:

Oracle Linux 7 is now in Extended Support. See Oracle Linux Extended Support and Oracle Open Source Support Policies for more information.

Migrate applications and data to Oracle Linux 8 or Oracle Linux 9 as soon as possible.

This chapter describes how to install and configure Performance Co-Pilot (PCP) so that you can analyze system performance across one or more Oracle Linux installations.

About PCP

PCP collects operating system and network metrics that you can use to diagnose performance issues. PCP provides a monitor host that you can use to send requests for metrics and logs to a pair of collector host services that are installed on each Oracle Linux system that you monitor.

Installing PCP

Enable the ol7_latest and ol7_addons yum repositories on your system.

For more information, see Oracle Linux 7: Managing Software.
Install the pcp-oracle-conf, pcp-system-tools and pcp-gui packages by using the yum command:
```
sudo yum install pcp-oracle-conf pcp-system-tools pcp-gui
```
Enable and start the Performance Metrics Collector Daemon (pmcd) and Performance Metrics Logger (pmlogger) collector host services:
```
sudo systemctl enable --now pmcd pmlogger
```

Stopping PCP

To temporarily halt data collection, stop the Performance Metrics Collector Daemon (pmcd) and Performance Metrics Logger (pmlogger) collector host services:

sudo systemctl stop pmcd pmlogger

To halt data collection for an indefinite period and ensure that that they don't start again automatically when the system boots, fully disable them:

sudo systemctl disable --now pmcd pmlogger

For more information about masking and unmasking services to prevent scripts from restarting disabled system services, see Oracle Linux 7: Managing Core System Configuration.

Reviewing Information Gathered by PCP

If the pcp-oracle-conf package is installed then the only metrics collected by the pmlogger service are those listed in the /var/lib/pcp/config/pmlogger/config.ora configuration file.

If PCP has been installed without the pcp-oracle-conf package, review the /var/lib/pcp/config/pmlogger/config.default configuration file instead.

You can modify the frequency with which those metrics are collected in the same configuration file. For example, to increase the frequency from once every minute to once every 5 seconds:

...
# It is safe to make additions from here on ...
#

log mandatory on every 5 seconds {
  filesys.free
  filesys.used
  ...
}

All of the archives that the pmlogger service generates are stored in the /var/log/pcp/pmlogger/hostname directory. For more information, see the pmlogconf(1) manual page.

To verify the PCP configuration at the time that pmlogger collected specific performance metrics, use the pcp command:

sudo pcp -a 20220321.0.xz

Using PCP Monitor Host to Analyze Performance Metrics

All of the archives that the pmlogger service generates are stored in the /var/log/pcp/pmlogger/hostname directory. If you navigate to that directory in a terminal, you can run a number of commands to review the performance metrics that have been collected.

For more information about those commands and their parameters, see their respective manual pages.

Review Live Performance Metrics in Real Time

To monitor all the outgoing metrics from the eth0 network interface in real time, use the pmrep command:

sudo pmrep -i eth0 -v network.interface.out

To monitor live hard drive operations for each partition with a two second interval, use the pmval command:

sudo pmval -t 2sec -f 3 disk.partitions.write

Review Recorded Performance Metrics

To review the data for specific performance metrics within a specified timespan, use the pmdumptext command. For example, to review resource usage metrics for CPU load, memory utilisation and disk write operations between 13:00 and 14:00 on a specific date:

sudo pmdumptext -Xlimu -t 10m -S @13:00 -T @14:00 \
 'kernel.all.load[1]' 'mem.util.used' 'disk.partitions.write' -a 20220321.0.xz

You can also use the pmstat to review system performance metrics in a format similar to that produced by the sar command. For example, to review performance metrics averaged over 10 minute interval between 09:00 and 10:00 on a specific date:

sudo pmstat -t 10m -S @09:00 -T @10:00 -a 20220321.0.xz

You can also compare the metrics between two time periods by using the pmdiff command. For example, to compare the metrics between 02:00 and 03:00 on one day to the metrics between 09:00 and 10:00 on a different day:

sudo pmdiff -S @02:00 -T @03:00 -B @09:00 -E @10:00 20220321.0.xz 20220320.0.xz

Review Details About Recorded Performance Metrics

To review detailed information about a specific metric, use the pminfo command. For example, to review details about free memory:

sudo pminfo -df mem.freemem -a 20220321.0.xz

Validate System Status When Performance Metrics Were Captured

To verify the host, timezone and time period that an archive containing performance metrics contains, use the pmdumplog command:

sudo pmdumplog -L 20220321.0.xz

To review a list of every enabled performance metric, use the pminfo command:

sudo pminfo -a 20220321.0.xz