Chapter 6. Monitoring performance with Performance Co-Pilot
Performance Co-Pilot (PCP) is a suite of tools, services, and libraries for monitoring, visualizing, storing, and analyzing system-level performance measurements.
As a system administrator, you can monitor the system’s performance using the the PCP application in Red Hat Enterprise Linux 9.
6.1. Monitoring postfix with pmda-postfix
This procedure describes how to monitor performance metrics of the
postfix mail server with
pmda-postfix. It helps to check how many emails are received per second.
Install the following packages:
# dnf install pcp-system-tools
pmda-postfixpackage to monitor
# dnf install pcp-pmda-postfix postfix
Install the logging daemon:
# dnf install rsyslog
Install the mail client for testing:
# dnf install mutt
# systemctl enable postfix rsyslog # systemctl restart postfix rsyslog
Enable the SELinux boolean, so that
pmda-postfixcan access the required log files:
# setsebool -P pcp_read_generic_logs=on
# cd /var/lib/pcp/pmdas/postfix/ # ./Install Updating the Performance Metrics Name Space (PMNS) ... Terminate PMDA if already installed ... Updating the PMCD control file, and notifying PMCD ... Waiting for pmcd to terminate ... Starting pmcd ... Check postfix metrics have appeared ... 7 metrics and 58 values
echo testmail | mutt root
Verify the available metrics:
# pminfo postfix postfix.received postfix.sent postfix.queues.incoming postfix.queues.maildrop postfix.queues.hold postfix.queues.deferred postfix.queues.active
6.2. Visually tracing PCP log archives with the PCP Charts application
After recording metric data, you can replay the PCP log archives as graphs. The metrics are sourced from one or more live hosts with alternative options to use metric data from PCP log archives as a source of historical data. To customize the PCP Charts application interface to display the data from the performance metrics, you can use line plot, bar graphs, or utilization graphs.
Using the PCP Charts application, you can:
- Replay the data in the PCP Charts application application and use graphs to visualize the retrospective data alongside live data of the system.
- Plot performance metric values into graphs.
- Display multiple charts simultaneously.
Launch the PCP Charts application from the command line:
Figure 6.1. PCP Charts application
pmtimeserver settings are located at the bottom. The start and pause button allows you to control:
- The interval in which PCP polls the metric data
- The date and time for the metrics of historical data
- Click File and then New Chart to select metric from both the local machine and remote machines by specifying their host name or address. Advanced configuration options include the ability to manually set the axis values for the chart, and to manually choose the color of the plots.
Record the views created in the PCP Charts application:
Following are the options to take images or record the views created in the PCP Charts application:
- Click File and then Export to save an image of the current view.
- Click Record and then Start to start a recording. Click Record and then Stop to stop the recording. After stopping the recording, the recorded metrics are archived to be viewed later.
Optional: In the PCP Charts application, the main configuration file, known as the view, allows the metadata associated with one or more charts to be saved. This metadata describes all chart aspects, including the metrics used and the chart columns. Save the custom view configuration by clicking File and then Save View, and load the view configuration later.
The following example of the PCP Charts application view configuration file describes a stacking chart graph showing the total number of bytes read and written to the given XFS file system
#kmchart version 1 chart title "Filesystem Throughput /loop1" style stacking antialiasing off plot legend "Read rate" metric xfs.read_bytes instance "loop1" plot legend "Write rate" metric xfs.write_bytes instance "loop1"
- Tools distributed with PCP
6.3. Collecting data from SQL server using PCP
The SQL Server agent is available in Performance Co-Pilot (PCP), which helps you to monitor and analyze database performance issues.
This procedure describes how to collect data for Microsoft SQL Server via
pcp on your system.
- You have installed Microsoft SQL Server for Red Hat Enterprise Linux and established a 'trusted' connection to an SQL server.
- You have installed the Microsoft ODBC driver for SQL Server for Red Hat Enterprise Linux.
# dnf install pcp-zeroconf
Install packages required for the
# dnf install python3-pyodbc
Install the Microsoft SQL Server domain agent for PCP:
# dnf install pcp-pmda-mssql
/etc/pcp/mssql/mssql.conffile to configure the SQL server account’s username and password for the
mssqlagent. Ensure that the account you configure has access rights to performance data.
username: user_name password: user_password
Replace user_name with the SQL Server account and user_password with the SQL Server user password for this account.
Install the agent:
# cd /var/lib/pcp/pmdas/mssql # ./Install Updating the Performance Metrics Name Space (PMNS) ... Terminate PMDA if already installed ... Updating the PMCD control file, and notifying PMCD ... Check mssql metrics have appeared ... 168 metrics and 598 values [...]
pcpcommand, verify if the SQL Server PMDA (
mssql) is loaded and running:
$ pcp Performance Co-Pilot configuration on rhel.local: platform: Linux rhel.local 4.18.0-167.el8.x86_64 #1 SMP Sun Dec 15 01:24:23 UTC 2019 x86_64 hardware: 2 cpus, 1 disk, 1 node, 2770MB RAM timezone: PDT+7 services: pmcd pmproxy pmcd: Version 5.0.2-1, 12 agents, 4 clients pmda: root pmcd proc pmproxy xfs linux nfsclient mmv kvm mssql jbd2 dm pmlogger: primary logger: /var/log/pcp/pmlogger/rhel.local/20200326.16.31 pmie: primary engine: /var/log/pcp/pmie/rhel.local/pmie.log
View the complete list of metrics that PCP can collect from the SQL Server:
# pminfo mssql
After viewing the list of metrics, you can report the rate of transactions. For example, to report on the overall transaction count per second, over a five second time window:
# pmval -t 1 -T 5 mssql.databases.transactions
View the graphical chart of these metrics on your system by using the
pmchartcommand. For more information, see Visually tracing PCP log archives with the PCP Charts application.
- Performance Co-Pilot for Microsoft SQL Server with RHEL 8.2 Red Hat Developers Blog post
6.4. Generating PCP archives from sadc archives
You can use the
sadf tool provided by the
sysstat package to generate PCP archives from native
sadcarchive has been created:
# /usr/lib64/sa/sadc 1 5 -
In this example,
sadcis sampling system data 1 time in a 5 second interval. The outfile is specified as
-which results in
sadcwriting the data to the standard system activity daily data file. This file is named saDD and is located in the /var/log/sa directory by default.
Generate a PCP archive from a
# sadf -l -O pcparchive=/tmp/recording -2
In this example, using the
-2option results in
sadfgenerating a PCP archive from a
sadcarchive recorded 2 days ago.
You can use PCP commands to inspect and analyze the PCP archive generated from a
sadc archive as you would a native PCP archive. For example:
To show a list of metrics in the PCP archive generated from an
sadcarchive archive, run:
$ pminfo --archive /tmp/recording Disk.dev.avactive Disk.dev.read Disk.dev.write Disk.dev.blkread [...]
To show the timespace of the archive and hostname of the PCP archive, run:
$ pmdumplog --label /tmp/recording Log Label (Log Format Version 2) Performance metrics from host shard commencing Tue Jul 20 00:10:30.642477 2021 ending Wed Jul 21 00:10:30.222176 2021
To plot performance metrics values into graphs, run:
$ pmchart --archive /tmp/recording