Chapter 8. Setting up graphical representation of PCP metrics
Using a combination of pcp
, grafana
, valkey
, pcp bpftrace
, and pcp vector
provides graphical representation of the live data or data collected by PCP.
8.1. Setting up PCP with pcp-zeroconf Copy linkLink copied to clipboard!
You can set up PCP on a system with the pcp-zeroconf
package. Once the pcp-zeroconf
package is installed, the system records the default set of metrics into archived files.
Procedure
Install the pcp-zeroconf package:
dnf install pcp-zeroconf
# dnf install pcp-zeroconf
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Verification
Ensure that the pmlogger service is active, and starts archiving the metrics:
pcp | grep pmlogger
# pcp | grep pmlogger pmlogger: primary logger: /var/log/pcp/pmlogger/localhost.localdomain/20200401.00.12
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8.2. Setting up a grafana-server Copy linkLink copied to clipboard!
Grafana generates graphs that are accessible from a browser. The grafana-server
is a back-end server for the Grafana dashboard. It listens, by default, on all interfaces, and provides web services accessed through the web browser. The grafana-pcp
plugin interacts with the pmproxy
daemon in the backend.
Prerequisites
- PCP is configured. For more information, see Setting up PCP with pcp-zeroconf.
Procedure
Install the following packages:
dnf install grafana grafana-pcp
# dnf install grafana grafana-pcp
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Restart and enable
grafana-server
:systemctl restart grafana-server systemctl enable grafana-server
# systemctl restart grafana-server # systemctl enable grafana-server
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Open the server’s firewall for network traffic to the Grafana service.
firewall-cmd --permanent --add-service=grafana firewall-cmd --reload
# firewall-cmd --permanent --add-service=grafana success # firewall-cmd --reload success
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Verification
Ensure that the
grafana-server
is listening and responding to requests:ss -ntlp | grep 3000
# ss -ntlp | grep 3000 LISTEN 0 128 :3000 *: users:(("grafana-server",pid=19522,fd=7))
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Ensure that the grafana-pcp plugin is installed:
grafana-cli plugins ls | grep performancecopilot-pcp-app
# grafana-cli plugins ls | grep performancecopilot-pcp-app performancecopilot-pcp-app @ 5.2.2
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8.3. Configuring valkey Copy linkLink copied to clipboard!
You can use the valkey data source to:
- View data archives
- Query time series using pmseries language
- Analyze data across multiple hosts
Prerequisites
- PCP is configured. For more information, see Setting up PCP with pcp-zeroconf.
-
The
grafana-server
is configured. For more information, see Setting up a grafana-server. -
Mail transfer agent, for example,
postfix
is installed and configured.
Procedure
Install the
valkey
package:dnf install valkey
# dnf install valkey
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Start and enable the
pmproxy
andvalkey
services:systemctl start pmproxy valkey systemctl enable pmproxy valkey
# systemctl start pmproxy valkey # systemctl enable pmproxy valkey
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Restart
grafana-server
:systemctl restart grafana-server
# systemctl restart grafana-server
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Verification
Ensure that the
pmproxy
andvalkey
are working:pmseries disk.dev.read
# pmseries disk.dev.read 2eb3e58d8f1e231361fb15cf1aa26fe534b4d9df
Copy to Clipboard Copied! Toggle word wrap Toggle overflow This command does not return any data if the valkey package is not installed.
For more information, see the
pmseries(1)
man page on your system.
8.4. Accessing the Grafana web UI Copy linkLink copied to clipboard!
You can access the Grafana web interface. Using the Grafana web interface, you can:
- add Valkey, PCP bpftrace, and PCP Vector data sources
- create a dashboard
- view an overview of any useful metrics
- create alerts in Valkey
Prerequisites
- PCP is configured. For more information, see Setting up PCP with pcp-zeroconf.
-
The
grafana-server
is configured. For more information, see Setting up a grafana-server.
Procedure
On the client system, open a browser and access the
grafana-server
on port 3000 by using the http://192.0.2.0:3000 link.Replace 192.0.2.0 with your machine IP when accessing Grafana web UI from a remote machine, or with localhost when accessing the web UI locally.
- For the first login, enter admin in both the Email or username and Password fields.
- Grafana prompts to set a New password to create a secured account. If you want to set it later, click Skip.
- From the hamburger icon (☰) on the top left, click Administration > Plugins.
- In the Plugins tab, type performance co-pilot in the Search by name or type text box and then click the Performance Co-Pilot (PCP) plugin.
- In the Plugins / Performance Co-Pilot pane, click Enable.
Click the Grafana icon. The Grafana Home page is displayed.
Figure 8.1. Home Dashboard
NoteThe top corner of the screen has a Settings icon, but it controls the general Dashboard settings.
In the Grafana Home page, click Add your first data source to add Valkey, PCP bpftrace, and PCP Vector data sources.
- To add PCP valkey data source, view default dashboard, create a panel, and an alert rule, see Creating panels and alerts in PCP valkey data source.
- To add pcp bpftrace data source and view the default dashboard, see Viewing the PCP bpftrace System Analysis dashboard.
- To add pcp vector data source, view the default dashboard, and to view the vector checklist, see Viewing the PCP Vector Checklist.
Optional: From the menu, hover over the admin profile icon to change the Preferences including Edit Profile, Change Password, or to Sign out.
For more information, see the
grafana-cli
andgrafana-server
man pages on your system.
8.5. Configuring secure connections for Valkey and PCP Copy linkLink copied to clipboard!
You can establish secure connections between Performance Co-Pilot (PCP), Grafana, and Valkey. Establishing secure connections between these components helps prevent unauthorized parties from accessing or modifying the data being collected and monitored.
Prerequisites
- PCP is installed. For more information, see Installing and enabling PCP.
- The Grafana server is configured. For more information, see Setting up a grafana-server.
- Valkey is installed. For more information, see Configuring Valkey.
-
The private client key is stored in the
/etc/valkey/client.key
file. If you use a different path, modify the path in the corresponding steps of the procedure. For details about creating a private key and certificate signing request (CSR), as well as how to request a certificate from a certificate authority (CA), see your CA’s documentation. -
The TLS client certificate is stored in the
/etc/valkey/client.crt
file. If you use a different path, modify the path in the corresponding steps of the procedure. -
The TLS server key is stored in the
/etc/valkey/valkey.key
file. If you use a different path, modify the path in the corresponding steps of the procedure. -
The TLS server certificate is stored in the
/etc/valkey/valkey.crt
file. If you use a different path, modify the path in the corresponding steps of the procedure. -
The CA certificate is stored in the
/etc/valkey/ca.crt
file. If you use a different path, modify the path in the corresponding steps of the procedure. -
For the
pmproxy
daemon, the private server key is stored in the/etc/pcp/tls/server.key
file. If you use a different path, modify the path in the corresponding steps of the procedure.
Procedure
As a root user, open the
/etc/valkey/valkey.conf
file and adjust the TLS/SSL options to reflect the following properties:Copy to Clipboard Copied! Toggle word wrap Toggle overflow Ensure valkey can access the TLS certificates:
su valkey -s /bin/bash -c \ 'ls -1 /etc/valkey/ca.crt /etc/valkey/valkey.key /etc/valkey/valkey.crt'
# su valkey -s /bin/bash -c \ 'ls -1 /etc/valkey/ca.crt /etc/valkey/valkey.key /etc/valkey/valkey.crt' /etc/valkey/ca.crt /etc/valkey/valkey.crt /etc/valkey/valkey.key
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Restart the valkey server to apply the configuration changes:
systemctl restart valkey
# systemctl restart valkey
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Verification
Confirm the TLS configuration works:
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8.6. Creating panels and alerts in PCP Valkey data source Copy linkLink copied to clipboard!
After adding the PCP Valkey data source, you can view the dashboard with an overview of useful metrics, add a query to visualize the load graph, and create alerts that help you to view the system issues after they occur.
Prerequisites
- The Valkey is configured. For more information, see Configuring Valkey.
-
The
grafana-server
is accessible. For more information, see Accessing the Grafana web UI.
Procedure
- Log into the Grafana web UI.
- In the Grafana Home page, click Add your first data source.
- In the Add data source pane, type valkey in the Filter by name or type text box and then click Valkey.
In the Data Sources / Valkey pane, perform the following:
- Add http://localhost:44322 in the URL field and then click Save & Test.
Click Dashboards tab > Import > Valkey: Host Overview to see a dashboard with an overview of any useful metrics.
Figure 8.2. Valkey: Host Overview
Add a new panel:
- From the menu, hover over the Create icon > Dashboard > Add new panel icon to add a panel.
-
In the Query tab, select the Valkey from the query list instead of the selected default option and in the text field of A, enter metric, for example,
kernel.all.load
to visualize the kernel load graph. - Optional: Add Panel title and Description, and update other options from the Settings.
- Click Save to apply changes and save the dashboard. Add Dashboard name.
Click Apply to apply changes and go back to the dashboard.
Figure 8.3. Valkey query panel
Create an alert rule:
- In the Valkey query panel, click Alert and then click Create Alert.
- Edit the Name, Evaluate query, and For fields from the Rule, and specify the Conditions for your alert.
Click Save to apply changes and save the dashboard. Click Apply to apply changes and go back to the dashboard.
Figure 8.4. Creating alerts in the Valkey panel
- Optional: In the same panel, scroll down and click Delete icon to delete the created rule.
- Optional: From the menu, click Alerting icon to view the created alert rules with different alert statuses, to edit the alert rule, or to pause the existing rule from the Alert Rules tab. To add a notification channel for the created alert rule to receive an alert notification from Grafana, see Adding notification channels for alerts.
8.7. Adding notification channels for alerts Copy linkLink copied to clipboard!
By adding notification channels, you can receive an alert notification from Grafana whenever the alert rule conditions are met and the system needs further monitoring. You can receive these alerts after selecting any one type from the supported list of notifiers, which includes DingDing, Discord, Email, Google Hangouts Chat, HipChat, Kafka REST Proxy, LINE, Microsoft Teams, OpsGenie, PagerDuty, Prometheus Alertmanager, Pushover, Sensu, Slack, Telegram, Threema Gateway, VictorOps, and webhook.
Prerequisites
-
The
grafana-server
is accessible. For more information, see Accessing the Grafana web UI. - An alert rule is created. For more information, see Creating panels and alerts in PCP valkey data source.
Configure SMTP and add a valid sender’s email address in the
grafana/grafana.ini
file:vi /etc/grafana/grafana.ini
# vi /etc/grafana/grafana.ini [smtp] enabled = true from_address = abc@gmail.com
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Restart grafana-server
systemctl restart grafana-server.service
# systemctl restart grafana-server.service
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Procedure
- From the menu, hover over the Alerting icon > click Notification channels > Add channel.
In the Add notification channel details pane, perform the following:
- Enter your name in the Name text box.
-
Select the communication Type, for example, Email and enter the email address. You can add multiple email addresses using the
;
separator. - Optional: Configure Optional Email settings and Notification settings.
- Click Save.
Select a notification channel in the alert rule:
- From the menu, hover over the Alerting icon and then click Alert rules.
- From the Alert Rules tab, click the created alert rule.
- On the Notifications tab, select your notification channel name from the Send to option, and then add an alert message.
- Click Apply.
8.8. Setting up authentication between PCP components Copy linkLink copied to clipboard!
You can set up authentication using the scram-sha-256
authentication mechanism, which is supported by PCP through the Simple Authentication Security Layer (SASL) framework.
Procedure
Install the SASL framework for the
scram-sha-256
authentication mechanism:dnf install cyrus-sasl-scram cyrus-sasl-lib
# dnf install cyrus-sasl-scram cyrus-sasl-lib
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pmcd.conf
file:vi /etc/sasl2/pmcd.conf
# vi /etc/sasl2/pmcd.conf mech_list: scram-sha-256 sasldb_path: /etc/pcp/passwd.db
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Create a new user:
useradd -r metrics
# useradd -r metrics
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Add the created user in the user database:
saslpasswd2 -a pmcd metrics
# saslpasswd2 -a pmcd metrics Password: Again (for verification):
Copy to Clipboard Copied! Toggle word wrap Toggle overflow To add the created user, it is required to enter the metrics account password.
Set the permissions of the user database:
chown root:pcp /etc/pcp/passwd.db chmod 640 /etc/pcp/passwd.db
# chown root:pcp /etc/pcp/passwd.db # chmod 640 /etc/pcp/passwd.db
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Restart the pmcd service:
systemctl restart pmcd
# systemctl restart pmcd
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Verification
Verify the SASL configuration:
pminfo -f -h "pcp://127.0.0.1?username=metrics" disk.dev.read
# pminfo -f -h "pcp://127.0.0.1?username=metrics" disk.dev.read Password: disk.dev.read inst [0 or "sda"] value 19540
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8.9. Installing PCP bpftrace Copy linkLink copied to clipboard!
You can install the PCP bpftrace
agent to introspect a system and to gather metrics from the kernel and user-space tracepoints. The bpftrace
agent uses bpftrace
scripts to gather the metrics. The bpftrace
scripts use the enhanced Berkeley Packet Filter (eBPF).
Prerequisites
- PCP is configured. For more information, see Setting up PCP with pcp-zeroconf.
-
The
grafana-server
is configured. For more information, see Setting up a grafana-server. -
The
scram-sha-256
authentication mechanism is configured. For more information, see Setting up authentication between PCP components.
Procedure
Install the
pcp-pmda-bpftrace
package:dnf install pcp-pmda-bpftrace
# dnf install pcp-pmda-bpftrace
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Edit the bpftrace.conf file and add the user that you have created in Setting up authentication between PCP components:
vi /var/lib/pcp/pmdas/bpftrace/bpftrace.conf
# vi /var/lib/pcp/pmdas/bpftrace/bpftrace.conf [dynamic_scripts] enabled = true auth_enabled = true allowed_users = root,metrics
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Install
bpftrace
PMDA:Copy to Clipboard Copied! Toggle word wrap Toggle overflow The
pmda-bpftrace
is now installed, and can only be used after authenticating your user. For more information, see Viewing the PCP bpftrace System Analysis dashboard.
8.10. Viewing the PCP bpftrace System Analysis dashboard Copy linkLink copied to clipboard!
Using the PCP bpftrace data source, you can access the live data from sources which are not available as normal data from the pmlogger or archives. In the PCP bpftrace data source, you can view the dashboard with an overview of useful metrics.
Prerequisites
-
The PCP
bpftrace
is installed. For more information, see Installing PCP bpftrace. -
The
grafana-server
is configured. For more information, see Setting up a grafana-server.
Procedure
- Log into the Grafana web UI.
- In the Grafana Home page, click Add your first data source.
-
In the Add data source pane, type
bpftrace
in the Filter by name or type text box and then click PCP bpftrace. In the Data Sources / PCP bpftrace pane, perform the following:
- Add http://localhost:44322 in the URL field.
- Toggle the Basic Auth option and add the created user credentials in the User and Password field.
Click Save & Test.
Figure 8.5. Adding PCP bpftrace in the data source
Click Dashboards tab > Import > PCP bpftrace: System Analysis to see a dashboard with an overview of any useful metrics.
Figure 8.6. PCP bpftrace: System Analysis
8.11. Installing PCP Vector Copy linkLink copied to clipboard!
You must install pcp vector before you start using it.
Prerequisites
- PCP is configured. For more information, see Setting up PCP with pcp-zeroconf.
-
The
grafana-server
is configured. For more information, see Setting up a grafana-server.
Procedure
Install the bcc PMDA:
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8.12. Viewing the PCP Vector Checklist Copy linkLink copied to clipboard!
The PCP Vector data source displays live metrics and uses the pcp metrics. It analyzes data for individual hosts. After adding the PCP Vector data source, you can view the dashboard with an overview of useful metrics and view the related troubleshooting or reference links in the checklist.
Prerequisites
- The PCP Vector is installed. For more information, see Installing PCP Vector.
-
The
grafana-server
is accessible. For more information, see Accessing the Grafana web UI.
Procedure
- Log into the Grafana web UI.
- In the Grafana Home page, click Add your first data source.
- In the Add data source pane, type vector in the Filter by name or type text box and then click PCP Vector.
In the Data Sources / PCP Vector pane, perform the following:
- Add http://localhost:44322 in the URL field and then click Save & Test.
Click Dashboards tab > Import * PCP Vector: Host Overview to see a dashboard with an overview of any useful metrics.
Figure 8.7. PCP Vector: Host Overview
From the menu, hover over the Performance Co-Pilot plugin and then click PCP Vector Checklist.
In the PCP checklist, click help or warning icon to view the related troubleshooting or reference links.
Figure 8.8. Performance Co-Pilot / PCP Vector Checklist
8.13. Using heatmaps in Grafana Copy linkLink copied to clipboard!
You can use heatmaps in Grafana to view histograms of your data over time, identify trends and patterns in your data, and see how they change over time. Each column within a heatmap represents a single histogram with different colored cells representing the different densities of observation of a given value within that histogram.
Prerequisites
- Valkey is configured. For more information see Configuring Valkey.
-
The
grafana-server
is accessible. For more information, see Accessing the Grafana web UI. - The PCP valkey data source is configured. For more information see Creating panels and alerts in PCP Valkey data source.
Procedure
- Hover the cursor over the Dashboards tab and click + New dashboard.
- In the Add panel menu, click Add a new panel.
In the Query tab:
- Select Valkey from the query list instead of the selected default option.
-
In the text field of A, enter a metric, for example,
kernel.all.load
to visualize the kernel load graph.
- Click the visualization dropdown menu, which is set to Time series by default, and then click Heatmap.
- Optional: In the Panel Options dropdown menu, add a Panel Title and Description.
In the Heatmap dropdown menu, under the Calculate from data setting, click Yes.
Figure 8.9. Heatmap
- Optional: In the Colors dropdown menu, change the Scheme from the default Orange and select the number of steps (color shades).
Optional: In the Tooltip dropdown menu, under the Show histogram (Y Axis) setting, click the toggle to display a cell’s position within its specific histogram when hovering your cursor over a cell in the heatmap. For example:
8.14. Managing SELinux booleans for Grafana Copy linkLink copied to clipboard!
The grafana-selinux
subpackage includes several SELinux booleans that control Grafana’s access to external services. These booleans are off by default. You can turn them on
or off
based on your system requirements.
Prerequisites
-
You have installed
grafana-selinux
subpackage. - You have root privileges.
Procedure
View all Grafana-related SELinux booleans:
semanage boolean -l | grep grafana
# semanage boolean -l | grep grafana
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Enable a SELinux boolean:
setsebool [-P] <boolean_name> on
# setsebool [-P] <boolean_name> on
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Replace <boolean_name> with the name of the SELinux boolean you want to enable.
- Use the -P option to make the change persistent across system reboots.
Optional: Turn off any SELinux option:
setsebool [-P] <boolean_name> off
# setsebool [-P] <boolean_name> off
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8.15. Troubleshooting Grafana issues Copy linkLink copied to clipboard!
At times, it is necessary to troubleshoot Grafana issues, such as, Grafana does not display any data, the dashboard is black, or similar issues.
Procedure
Verify that the
pmlogger
service is up and running by executing the following command:systemctl status pmlogger
$ systemctl status pmlogger
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Verify if files were created or modified to the disk by executing the following command:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Verify that the
pmproxy
service is running by executing the following command:systemctl status pmproxy
$ systemctl status pmproxy
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Verify that
pmproxy
is running, time series support is enabled, and a connection to valkey is established by viewing the/var/log/pcp/pmproxy/pmproxy.log
file and ensure that it contains the following text:pmproxy(1716) Info: valkey slots, command keys, schema version setup Here, 1716 is the PID of pmproxy, which will be different for every invocation of pmproxy. Verify if the valkey database contains any keys by executing the following command: $ valkey-cli dbsize (integer) 34837
pmproxy(1716) Info: valkey slots, command keys, schema version setup Here, 1716 is the PID of pmproxy, which will be different for every invocation of pmproxy. Verify if the valkey database contains any keys by executing the following command: $ valkey-cli dbsize (integer) 34837
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Verify if any PCP metrics are in the valkey database and pmproxy is able to access them by executing the following commands:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Verify if there are any errors in the Grafana logs by executing the following command:
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