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Chapter 13. Using PTP hardware
Precision Time Protocol (PTP) hardware with single NIC configured as boundary clock is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.
13.1. About PTP hardware Copia collegamentoCollegamento copiato negli appunti!
You can configure linuxptp services and use PTP-capable hardware in OpenShift Container Platform cluster nodes.
The PTP Operator works with PTP-capable devices on clusters provisioned only on bare-metal infrastructure.
You can use the OpenShift Container Platform console or OpenShift CLI (oc) to install PTP by deploying the PTP Operator. The PTP Operator creates and manages the linuxptp services and provides the following features:
- Discovery of the PTP-capable devices in the cluster.
-
Management of the configuration of
linuxptpservices. -
Notification of PTP clock events that negatively affect the performance and reliability of your application with the PTP Operator
cloud-event-proxysidecar.
13.2. About PTP Copia collegamentoCollegamento copiato negli appunti!
Precision Time Protocol (PTP) is used to synchronize clocks in a network. When used in conjunction with hardware support, PTP is capable of sub-microsecond accuracy, and is more accurate than Network Time Protocol (NTP).
The linuxptp package includes the ptp4l and phc2sys programs for clock synchronization. ptp4l implements the PTP boundary clock and ordinary clock. ptp4l synchronizes the PTP hardware clock to the source clock with hardware time stamping and synchronizes the system clock to the source clock with software time stamping. phc2sys is used for hardware time stamping to synchronize the system clock to the PTP hardware clock on the network interface controller (NIC).
13.2.1. Elements of a PTP domain Copia collegamentoCollegamento copiato negli appunti!
PTP is used to synchronize multiple nodes connected in a network, with clocks for each node. The clocks synchronized by PTP are organized in a source-destination hierarchy. The hierarchy is created and updated automatically by the best master clock (BMC) algorithm, which runs on every clock. Destination clocks are synchronized to source clocks, and destination clocks can themselves be the source for other downstream clocks. The following types of clocks can be included in configurations:
- Grandmaster clock
- The grandmaster clock provides standard time information to other clocks across the network and ensures accurate and stable synchronisation. It writes time stamps and responds to time requests from other clocks. Grandmaster clocks can be synchronized to a Global Positioning System (GPS) time source.
- Ordinary clock
- The ordinary clock has a single port connection that can play the role of source or destination clock, depending on its position in the network. The ordinary clock can read and write time stamps.
- Boundary clock
- The boundary clock has ports in two or more communication paths and can be a source and a destination to other destination clocks at the same time. The boundary clock works as a destination clock upstream. The destination clock receives the timing message, adjusts for delay, and then creates a new source time signal to pass down the network. The boundary clock produces a new timing packet that is still correctly synced with the source clock and can reduce the number of connected devices reporting directly to the source clock.
13.2.2. Advantages of PTP over NTP Copia collegamentoCollegamento copiato negli appunti!
One of the main advantages that PTP has over NTP is the hardware support present in various network interface controllers (NIC) and network switches. The specialized hardware allows PTP to account for delays in message transfer and improves the accuracy of time synchronization. To achieve the best possible accuracy, it is recommended that all networking components between PTP clocks are PTP hardware enabled.
Hardware-based PTP provides optimal accuracy, since the NIC can time stamp the PTP packets at the exact moment they are sent and received. Compare this to software-based PTP, which requires additional processing of the PTP packets by the operating system.
Before enabling PTP, ensure that NTP is disabled for the required nodes. You can disable the chrony time service (chronyd) using a MachineConfig custom resource. For more information, see Disabling chrony time service.
13.3. Installing the PTP Operator using the CLI Copia collegamentoCollegamento copiato negli appunti!
As a cluster administrator, you can install the Operator by using the CLI.
Prerequisites
- A cluster installed on bare-metal hardware with nodes that have hardware that supports PTP.
-
Install the OpenShift CLI (
oc). -
Log in as a user with
cluster-adminprivileges.
Procedure
Create a namespace for the PTP Operator.
Save the following YAML in the
ptp-namespace.yamlfile:Copy to Clipboard Copied! Toggle word wrap Toggle overflow Create the
NamespaceCR:oc create -f ptp-namespace.yaml
$ oc create -f ptp-namespace.yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow
Create an Operator group for the PTP Operator.
Save the following YAML in the
ptp-operatorgroup.yamlfile:Copy to Clipboard Copied! Toggle word wrap Toggle overflow Create the
OperatorGroupCR:oc create -f ptp-operatorgroup.yaml
$ oc create -f ptp-operatorgroup.yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow
Subscribe to the PTP Operator.
Save the following YAML in the
ptp-sub.yamlfile:Copy to Clipboard Copied! Toggle word wrap Toggle overflow Create the
SubscriptionCR:oc create -f ptp-sub.yaml
$ oc create -f ptp-sub.yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow
To verify that the Operator is installed, enter the following command:
oc get csv -n openshift-ptp -o custom-columns=Name:.metadata.name,Phase:.status.phase
$ oc get csv -n openshift-ptp -o custom-columns=Name:.metadata.name,Phase:.status.phaseCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
Name Phase 4.10.0-202201261535 Succeeded
Name Phase 4.10.0-202201261535 SucceededCopy to Clipboard Copied! Toggle word wrap Toggle overflow
13.4. Installing the PTP Operator using the web console Copia collegamentoCollegamento copiato negli appunti!
As a cluster administrator, you can install the PTP Operator using the web console.
You have to create the namespace and Operator group as mentioned in the previous section.
Procedure
Install the PTP Operator using the OpenShift Container Platform web console:
-
In the OpenShift Container Platform web console, click Operators
OperatorHub. - Choose PTP Operator from the list of available Operators, and then click Install.
- On the Install Operator page, under A specific namespace on the cluster select openshift-ptp. Then, click Install.
-
In the OpenShift Container Platform web console, click Operators
Optional: Verify that the PTP Operator installed successfully:
-
Switch to the Operators
Installed Operators page. Ensure that PTP Operator is listed in the openshift-ptp project with a Status of InstallSucceeded.
NoteDuring installation an Operator might display a Failed status. If the installation later succeeds with an InstallSucceeded message, you can ignore the Failed message.
If the Operator does not appear as installed, to troubleshoot further:
-
Go to the Operators
Installed Operators page and inspect the Operator Subscriptions and Install Plans tabs for any failure or errors under Status. -
Go to the Workloads
Pods page and check the logs for pods in the openshift-ptpproject.
-
Go to the Operators
-
Switch to the Operators
13.5. Configuring PTP devices Copia collegamentoCollegamento copiato negli appunti!
The PTP Operator adds the NodePtpDevice.ptp.openshift.io custom resource definition (CRD) to OpenShift Container Platform.
When installed, the PTP Operator searches your cluster for PTP-capable network devices on each node. It creates and updates a NodePtpDevice custom resource (CR) object for each node that provides a compatible PTP-capable network device.
13.5.1. Discovering PTP capable network devices in your cluster Copia collegamentoCollegamento copiato negli appunti!
To return a complete list of PTP capable network devices in your cluster, run the following command:
oc get NodePtpDevice -n openshift-ptp -o yaml
$ oc get NodePtpDevice -n openshift-ptp -o yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
13.5.2. Configuring linuxptp services as a grandmaster clock Copia collegamentoCollegamento copiato negli appunti!
You can configure the linuxptp services (ptp4l, phc2sys, ts2phc) as grandmaster clock by creating a PtpConfig custom resource (CR) that configures the host NIC.
The ts2phc utility allows you to synchronize the system clock with the PTP grandmaster clock so that the node can stream precision clock signal to downstream PTP ordinary clocks and boundary clocks.
Use the following example PtpConfig CR as the basis to configure linuxptp services as the grandmaster clock for your particular hardware and environment. This example CR does not configure PTP fast events. To configure PTP fast events, set appropriate values for ptp4lOpts, ptp4lConf, and ptpClockThreshold. ptpClockThreshold is used only when events are enabled. See "Configuring the PTP fast event notifications publisher" for more information.
Prerequisites
- Install an Intel Westport Channel network interface in the bare-metal cluster host.
-
Install the OpenShift CLI (
oc). -
Log in as a user with
cluster-adminprivileges. - Install the PTP Operator.
Procedure
Create the
PtpConfigresource. For example:Save the following YAML in the
grandmaster-clock-ptp-config.yamlfile:Example PTP grandmaster clock configuration
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Create the CR by running the following command:
oc create -f grandmaster-clock-ptp-config.yaml
$ oc create -f grandmaster-clock-ptp-config.yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow
Verification
Check that the
PtpConfigprofile is applied to the node.Get the list of pods in the
openshift-ptpnamespace by running the following command:oc get pods -n openshift-ptp -o wide
$ oc get pods -n openshift-ptp -o wideCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-74m2g 3/3 Running 3 4d15h 10.16.230.7 compute-1.example.com ptp-operator-5f4f48d7c-x7zkf 1/1 Running 1 4d15h 10.128.1.145 compute-1.example.com
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-74m2g 3/3 Running 3 4d15h 10.16.230.7 compute-1.example.com ptp-operator-5f4f48d7c-x7zkf 1/1 Running 1 4d15h 10.128.1.145 compute-1.example.comCopy to Clipboard Copied! Toggle word wrap Toggle overflow Check that the profile is correct. Examine the logs of the
linuxptpdaemon that corresponds to the node you specified in thePtpConfigprofile. Run the following command:oc logs linuxptp-daemon-74m2g -n openshift-ptp -c linuxptp-daemon-container
$ oc logs linuxptp-daemon-74m2g -n openshift-ptp -c linuxptp-daemon-containerCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
13.5.3. Configuring linuxptp services as an ordinary clock Copia collegamentoCollegamento copiato negli appunti!
You can configure linuxptp services (ptp4l, phc2sys) as ordinary clock by creating a PtpConfig custom resource (CR) object.
Use the following example PtpConfig CR as the basis to configure linuxptp services as an ordinary clock for your particular hardware and environment. This example CR does not configure PTP fast events. To configure PTP fast events, set appropriate values for ptp4lOpts, ptp4lConf, and ptpClockThreshold. ptpClockThreshold is required only when events are enabled. See "Configuring the PTP fast event notifications publisher" for more information.
Prerequisites
-
Install the OpenShift CLI (
oc). -
Log in as a user with
cluster-adminprivileges. - Install the PTP Operator.
Procedure
Create the following
PtpConfigCR, and then save the YAML in theordinary-clock-ptp-config.yamlfile.Example PTP ordinary clock configuration
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Expand Table 13.1. PTP ordinary clock CR configuration options Custom resource field Description nameThe name of the
PtpConfigCR.profileSpecify an array of one or more
profileobjects. Each profile must be uniquely named.interfaceSpecify the network interface to be used by the
ptp4lservice, for exampleens787f1.ptp4lOptsSpecify system config options for the
ptp4lservice, for example-2to select the IEEE 802.3 network transport. The options should not include the network interface name-i <interface>and service config file-f /etc/ptp4l.confbecause the network interface name and the service config file are automatically appended. Append--summary_interval -4to use PTP fast events with this interface.phc2sysOptsSpecify system config options for the
phc2sysservice. If this field is empty, the PTP Operator does not start thephc2sysservice. For Intel Columbiaville 800 Series NICs, setphc2sysOptsoptions to-a -r -m -n 24 -N 8 -R 16.-mprints messages tostdout. Thelinuxptp-daemonDaemonSetparses the logs and generates Prometheus metrics.ptp4lConfSpecify a string that contains the configuration to replace the default
/etc/ptp4l.conffile. To use the default configuration, leave the field empty.tx_timestamp_timeoutFor Intel Columbiaville 800 Series NICs, set
tx_timestamp_timeoutto50.boundary_clock_jbodFor Intel Columbiaville 800 Series NICs, set
boundary_clock_jbodto0.ptpSchedulingPolicyScheduling policy for
ptp4landphc2sysprocesses. Default value isSCHED_OTHER. UseSCHED_FIFOon systems that support FIFO scheduling.ptpSchedulingPriorityInteger value from 1-65 used to set FIFO priority for
ptp4landphc2sysprocesses whenptpSchedulingPolicyis set toSCHED_FIFO. TheptpSchedulingPriorityfield is not used whenptpSchedulingPolicyis set toSCHED_OTHER.ptpClockThresholdOptional. If
ptpClockThresholdis not present, default values are used for theptpClockThresholdfields.ptpClockThresholdconfigures how long after the PTP master clock is disconnected before PTP events are triggered.holdOverTimeoutis the time value in seconds before the PTP clock event state changes toFREERUNwhen the PTP master clock is disconnected. ThemaxOffsetThresholdandminOffsetThresholdsettings configure offset values in nanoseconds that compare against the values forCLOCK_REALTIME(phc2sys) or master offset (ptp4l). When theptp4lorphc2sysoffset value is outside this range, the PTP clock state is set toFREERUN. When the offset value is within this range, the PTP clock state is set toLOCKED.recommendSpecify an array of one or more
recommendobjects that define rules on how theprofileshould be applied to nodes..recommend.profileSpecify the
.recommend.profileobject name defined in theprofilesection..recommend.prioritySet
.recommend.priorityto0for ordinary clock..recommend.matchSpecify
.recommend.matchrules withnodeLabelornodeName..recommend.match.nodeLabelUpdate
nodeLabelwith thekeyofnode.Labelsfrom the node object by using theoc get nodes --show-labelscommand. For example:node-role.kubernetes.io/worker..recommend.match.nodeLabelUpdate
nodeNamewith value ofnode.Namefrom the node object by using theoc get nodescommand. For example:compute-0.example.com.Create the
PtpConfigCR by running the following command:oc create -f ordinary-clock-ptp-config.yaml
$ oc create -f ordinary-clock-ptp-config.yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow
Verification
Check that the
PtpConfigprofile is applied to the node.Get the list of pods in the
openshift-ptpnamespace by running the following command:oc get pods -n openshift-ptp -o wide
$ oc get pods -n openshift-ptp -o wideCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-4xkbb 1/1 Running 0 43m 10.1.196.24 compute-0.example.com linuxptp-daemon-tdspf 1/1 Running 0 43m 10.1.196.25 compute-1.example.com ptp-operator-657bbb64c8-2f8sj 1/1 Running 0 43m 10.129.0.61 control-plane-1.example.com
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-4xkbb 1/1 Running 0 43m 10.1.196.24 compute-0.example.com linuxptp-daemon-tdspf 1/1 Running 0 43m 10.1.196.25 compute-1.example.com ptp-operator-657bbb64c8-2f8sj 1/1 Running 0 43m 10.129.0.61 control-plane-1.example.comCopy to Clipboard Copied! Toggle word wrap Toggle overflow Check that the profile is correct. Examine the logs of the
linuxptpdaemon that corresponds to the node you specified in thePtpConfigprofile. Run the following command:oc logs linuxptp-daemon-4xkbb -n openshift-ptp -c linuxptp-daemon-container
$ oc logs linuxptp-daemon-4xkbb -n openshift-ptp -c linuxptp-daemon-containerCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
13.5.4. Configuring linuxptp services as a boundary clock Copia collegamentoCollegamento copiato negli appunti!
You can configure the linuxptp services (ptp4l, phc2sys) as boundary clock by creating a PtpConfig custom resource (CR) object.
Use the following example PtpConfig CR as the basis to configure linuxptp services as the boundary clock for your particular hardware and environment. This example CR does not configure PTP fast events. To configure PTP fast events, set appropriate values for ptp4lOpts, ptp4lConf, and ptpClockThreshold. ptpClockThreshold is used only when events are enabled. See "Configuring the PTP fast event notifications publisher" for more information.
Prerequisites
-
Install the OpenShift CLI (
oc). -
Log in as a user with
cluster-adminprivileges. - Install the PTP Operator.
Procedure
Create the following
PtpConfigCR, and then save the YAML in theboundary-clock-ptp-config.yamlfile.Example PTP boundary clock configuration
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Expand Table 13.2. PTP boundary clock CR configuration options Custom resource field Description nameThe name of the
PtpConfigCR.profileSpecify an array of one or more
profileobjects.nameSpecify the name of a profile object which uniquely identifies a profile object.
ptp4lOptsSpecify system config options for the
ptp4lservice. The options should not include the network interface name-i <interface>and service config file-f /etc/ptp4l.confbecause the network interface name and the service config file are automatically appended.ptp4lConfSpecify the required configuration to start
ptp4las boundary clock. For example,ens1f0synchronizes from a grandmaster clock andens1f3synchronizes connected devices.<interface_1>The interface that receives the synchronization clock.
<interface_2>The interface that sends the synchronization clock.
tx_timestamp_timeoutFor Intel Columbiaville 800 Series NICs, set
tx_timestamp_timeoutto50.boundary_clock_jbodFor Intel Columbiaville 800 Series NICs, ensure
boundary_clock_jbodis set to0. For Intel Fortville X710 Series NICs, ensureboundary_clock_jbodis set to1.phc2sysOptsSpecify system config options for the
phc2sysservice. If this field is empty, the PTP Operator does not start thephc2sysservice.ptpSchedulingPolicyScheduling policy for ptp4l and phc2sys processes. Default value is
SCHED_OTHER. UseSCHED_FIFOon systems that support FIFO scheduling.ptpSchedulingPriorityInteger value from 1-65 used to set FIFO priority for
ptp4landphc2sysprocesses whenptpSchedulingPolicyis set toSCHED_FIFO. TheptpSchedulingPriorityfield is not used whenptpSchedulingPolicyis set toSCHED_OTHER.ptpClockThresholdOptional. If
ptpClockThresholdis not present, default values are used for theptpClockThresholdfields.ptpClockThresholdconfigures how long after the PTP master clock is disconnected before PTP events are triggered.holdOverTimeoutis the time value in seconds before the PTP clock event state changes toFREERUNwhen the PTP master clock is disconnected. ThemaxOffsetThresholdandminOffsetThresholdsettings configure offset values in nanoseconds that compare against the values forCLOCK_REALTIME(phc2sys) or master offset (ptp4l). When theptp4lorphc2sysoffset value is outside this range, the PTP clock state is set toFREERUN. When the offset value is within this range, the PTP clock state is set toLOCKED.recommendSpecify an array of one or more
recommendobjects that define rules on how theprofileshould be applied to nodes..recommend.profileSpecify the
.recommend.profileobject name defined in theprofilesection..recommend.prioritySpecify the
prioritywith an integer value between0and99. A larger number gets lower priority, so a priority of99is lower than a priority of10. If a node can be matched with multiple profiles according to rules defined in thematchfield, the profile with the higher priority is applied to that node..recommend.matchSpecify
.recommend.matchrules withnodeLabelornodeName..recommend.match.nodeLabelUpdate
nodeLabelwith thekeyofnode.Labelsfrom the node object by using theoc get nodes --show-labelscommand. For example:node-role.kubernetes.io/worker..recommend.match.nodeLabelUpdate
nodeNamewith value ofnode.Namefrom the node object by using theoc get nodescommand. For example:compute-0.example.com.Create the CR by running the following command:
oc create -f boundary-clock-ptp-config.yaml
$ oc create -f boundary-clock-ptp-config.yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow
Verification
Check that the
PtpConfigprofile is applied to the node.Get the list of pods in the
openshift-ptpnamespace by running the following command:oc get pods -n openshift-ptp -o wide
$ oc get pods -n openshift-ptp -o wideCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-4xkbb 1/1 Running 0 43m 10.1.196.24 compute-0.example.com linuxptp-daemon-tdspf 1/1 Running 0 43m 10.1.196.25 compute-1.example.com ptp-operator-657bbb64c8-2f8sj 1/1 Running 0 43m 10.129.0.61 control-plane-1.example.com
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-4xkbb 1/1 Running 0 43m 10.1.196.24 compute-0.example.com linuxptp-daemon-tdspf 1/1 Running 0 43m 10.1.196.25 compute-1.example.com ptp-operator-657bbb64c8-2f8sj 1/1 Running 0 43m 10.129.0.61 control-plane-1.example.comCopy to Clipboard Copied! Toggle word wrap Toggle overflow Check that the profile is correct. Examine the logs of the
linuxptpdaemon that corresponds to the node you specified in thePtpConfigprofile. Run the following command:oc logs linuxptp-daemon-4xkbb -n openshift-ptp -c linuxptp-daemon-container
$ oc logs linuxptp-daemon-4xkbb -n openshift-ptp -c linuxptp-daemon-containerCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
13.5.5. Intel Columbiaville E800 series NIC as PTP ordinary clock reference Copia collegamentoCollegamento copiato negli appunti!
The following table describes the changes that you must make to the reference PTP configuration in order to use Intel Columbiaville E800 series NICs as ordinary clocks. Make the changes in a PtpConfig custom resource (CR) that you apply to the cluster.
| PTP configuration | Recommended setting |
|---|---|
|
|
|
|
|
|
|
|
|
For phc2sysOpts, -m prints messages to stdout. The linuxptp-daemon DaemonSet parses the logs and generates Prometheus metrics.
13.5.6. Configuring FIFO priority scheduling for PTP hardware Copia collegamentoCollegamento copiato negli appunti!
In telco or other deployment configurations that require low latency performance, PTP daemon threads run in a constrained CPU footprint alongside the rest of the infrastructure components. By default, PTP threads run with the SCHED_OTHER policy. Under high load, these threads might not get the scheduling latency they require for error-free operation.
To mitigate against potential scheduling latency errors, you can configure the PTP Operator linuxptp services to allow threads to run with a SCHED_FIFO policy. If SCHED_FIFO is set for a PtpConfig CR, then ptp4l and phc2sys will run in the parent container under chrt with a priority set by the ptpSchedulingPriority field of the PtpConfig CR.
Setting ptpSchedulingPolicy is optional, and is only required if you are experiencing latency errors.
Procedure
Edit the
PtpConfigCR profile:oc edit PtpConfig -n openshift-ptp
$ oc edit PtpConfig -n openshift-ptpCopy to Clipboard Copied! Toggle word wrap Toggle overflow Change the
ptpSchedulingPolicyandptpSchedulingPriorityfields:Copy to Clipboard Copied! Toggle word wrap Toggle overflow -
Save and exit to apply the changes to the
PtpConfigCR.
Verification
Get the name of the
linuxptp-daemonpod and corresponding node where thePtpConfigCR has been applied:oc get pods -n openshift-ptp -o wide
$ oc get pods -n openshift-ptp -o wideCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-gmv2n 3/3 Running 0 1d17h 10.1.196.24 compute-0.example.com linuxptp-daemon-lgm55 3/3 Running 0 1d17h 10.1.196.25 compute-1.example.com ptp-operator-3r4dcvf7f4-zndk7 1/1 Running 0 1d7h 10.129.0.61 control-plane-1.example.com
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-gmv2n 3/3 Running 0 1d17h 10.1.196.24 compute-0.example.com linuxptp-daemon-lgm55 3/3 Running 0 1d17h 10.1.196.25 compute-1.example.com ptp-operator-3r4dcvf7f4-zndk7 1/1 Running 0 1d7h 10.129.0.61 control-plane-1.example.comCopy to Clipboard Copied! Toggle word wrap Toggle overflow Check that the
ptp4lprocess is running with the updatedchrtFIFO priority:oc -n openshift-ptp logs linuxptp-daemon-lgm55 -c linuxptp-daemon-container|grep chrt
$ oc -n openshift-ptp logs linuxptp-daemon-lgm55 -c linuxptp-daemon-container|grep chrtCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
I1216 19:24:57.091872 1600715 daemon.go:285] /bin/chrt -f 65 /usr/sbin/ptp4l -f /var/run/ptp4l.0.config -2 --summary_interval -4 -m
I1216 19:24:57.091872 1600715 daemon.go:285] /bin/chrt -f 65 /usr/sbin/ptp4l -f /var/run/ptp4l.0.config -2 --summary_interval -4 -mCopy to Clipboard Copied! Toggle word wrap Toggle overflow
13.6. Troubleshooting common PTP Operator issues Copia collegamentoCollegamento copiato negli appunti!
Troubleshoot common problems with the PTP Operator by performing the following steps.
Prerequisites
-
Install the OpenShift Container Platform CLI (
oc). -
Log in as a user with
cluster-adminprivileges. - Install the PTP Operator on a bare-metal cluster with hosts that support PTP.
Procedure
Check the Operator and operands are successfully deployed in the cluster for the configured nodes.
oc get pods -n openshift-ptp -o wide
$ oc get pods -n openshift-ptp -o wideCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-lmvgn 3/3 Running 0 4d17h 10.1.196.24 compute-0.example.com linuxptp-daemon-qhfg7 3/3 Running 0 4d17h 10.1.196.25 compute-1.example.com ptp-operator-6b8dcbf7f4-zndk7 1/1 Running 0 5d7h 10.129.0.61 control-plane-1.example.com
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-lmvgn 3/3 Running 0 4d17h 10.1.196.24 compute-0.example.com linuxptp-daemon-qhfg7 3/3 Running 0 4d17h 10.1.196.25 compute-1.example.com ptp-operator-6b8dcbf7f4-zndk7 1/1 Running 0 5d7h 10.129.0.61 control-plane-1.example.comCopy to Clipboard Copied! Toggle word wrap Toggle overflow NoteWhen the PTP fast event bus is enabled, the number of ready
linuxptp-daemonpods is3/3. If the PTP fast event bus is not enabled,2/2is displayed.Check that supported hardware is found in the cluster.
oc -n openshift-ptp get nodeptpdevices.ptp.openshift.io
$ oc -n openshift-ptp get nodeptpdevices.ptp.openshift.ioCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Check the available PTP network interfaces for a node:
oc -n openshift-ptp get nodeptpdevices.ptp.openshift.io <node_name> -o yaml
$ oc -n openshift-ptp get nodeptpdevices.ptp.openshift.io <node_name> -o yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow where:
- <node_name>
Specifies the node you want to query, for example,
compute-0.example.com.Example output
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
Check that the PTP interface is successfully synchronized to the primary clock by accessing the
linuxptp-daemonpod for the corresponding node.Get the name of the
linuxptp-daemonpod and corresponding node you want to troubleshoot by running the following command:oc get pods -n openshift-ptp -o wide
$ oc get pods -n openshift-ptp -o wideCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-lmvgn 3/3 Running 0 4d17h 10.1.196.24 compute-0.example.com linuxptp-daemon-qhfg7 3/3 Running 0 4d17h 10.1.196.25 compute-1.example.com ptp-operator-6b8dcbf7f4-zndk7 1/1 Running 0 5d7h 10.129.0.61 control-plane-1.example.com
NAME READY STATUS RESTARTS AGE IP NODE linuxptp-daemon-lmvgn 3/3 Running 0 4d17h 10.1.196.24 compute-0.example.com linuxptp-daemon-qhfg7 3/3 Running 0 4d17h 10.1.196.25 compute-1.example.com ptp-operator-6b8dcbf7f4-zndk7 1/1 Running 0 5d7h 10.129.0.61 control-plane-1.example.comCopy to Clipboard Copied! Toggle word wrap Toggle overflow Remote shell into the required
linuxptp-daemoncontainer:oc rsh -n openshift-ptp -c linuxptp-daemon-container <linux_daemon_container>
$ oc rsh -n openshift-ptp -c linuxptp-daemon-container <linux_daemon_container>Copy to Clipboard Copied! Toggle word wrap Toggle overflow where:
- <linux_daemon_container>
-
is the container you want to diagnose, for example
linuxptp-daemon-lmvgn.
In the remote shell connection to the
linuxptp-daemoncontainer, use the PTP Management Client (pmc) tool to diagnose the network interface. Run the followingpmccommand to check the sync status of the PTP device, for exampleptp4l.pmc -u -f /var/run/ptp4l.0.config -b 0 'GET PORT_DATA_SET'
# pmc -u -f /var/run/ptp4l.0.config -b 0 'GET PORT_DATA_SET'Copy to Clipboard Copied! Toggle word wrap Toggle overflow Example output when the node is successfully synced to the primary clock
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
13.7. PTP hardware fast event notifications framework Copia collegamentoCollegamento copiato negli appunti!
PTP events with ordinary clock is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.
13.7.1. About PTP and clock synchronization error events Copia collegamentoCollegamento copiato negli appunti!
Cloud native applications such as virtual RAN require access to notifications about hardware timing events that are critical to the functioning of the overall network. Fast event notifications are early warning signals about impending and real-time Precision Time Protocol (PTP) clock synchronization events. PTP clock synchronization errors can negatively affect the performance and reliability of your low latency application, for example, a vRAN application running in a distributed unit (DU).
Loss of PTP synchronization is a critical error for a RAN network. If synchronization is lost on a node, the radio might be shut down and the network Over the Air (OTA) traffic might be shifted to another node in the wireless network. Fast event notifications mitigate against workload errors by allowing cluster nodes to communicate PTP clock sync status to the vRAN application running in the DU.
Event notifications are available to RAN applications running on the same DU node. A publish/subscribe REST API passes events notifications to the messaging bus. Publish/subscribe messaging, or pub/sub messaging, is an asynchronous service to service communication architecture where any message published to a topic is immediately received by all the subscribers to the topic.
Fast event notifications are generated by the PTP Operator in OpenShift Container Platform for every PTP-capable network interface. The events are made available using a cloud-event-proxy sidecar container over an Advanced Message Queuing Protocol (AMQP) message bus. The AMQP message bus is provided by the AMQ Interconnect Operator.
PTP fast event notifications are available for network interfaces configured to use PTP ordinary clocks or PTP boundary clocks.
13.7.2. About the PTP fast event notifications framework Copia collegamentoCollegamento copiato negli appunti!
You can subscribe distributed unit (DU) applications to Precision Time Protocol (PTP) fast events notifications that are generated by OpenShift Container Platform with the PTP Operator and cloud-event-proxy sidecar container. You enable the cloud-event-proxy sidecar container by setting the enableEventPublisher field to true in the ptpOperatorConfig custom resource (CR) and specifying an Advanced Message Queuing Protocol (AMQP) transportHost address. PTP fast events use an AMQP event notification bus provided by the AMQ Interconnect Operator. AMQ Interconnect is a component of Red Hat AMQ, a messaging router that provides flexible routing of messages between any AMQP-enabled endpoints. An overview of the PTP fast events framework is below:
Figure 13.1. Overview of PTP fast events
The cloud-event-proxy sidecar container can access the same resources as the primary vRAN application without using any of the resources of the primary application and with no significant latency.
The fast events notifications framework uses a REST API for communication and is based on the O-RAN REST API specification. The framework consists of a publisher, subscriber, and an AMQ messaging bus to handle communications between the publisher and subscriber applications. The cloud-event-proxy sidecar is a utility container that runs in a pod that is loosely coupled to the main DU application container on the DU node. It provides an event publishing framework that allows you to subscribe DU applications to published PTP events.
DU applications run the cloud-event-proxy container in a sidecar pattern to subscribe to PTP events. The following workflow describes how a DU application uses PTP fast events:
-
DU application requests a subscription: The DU sends an API request to the
cloud-event-proxysidecar to create a PTP events subscription. Thecloud-event-proxysidecar creates a subscription resource. -
cloud-event-proxy sidecar creates the subscription: The event resource is persisted by the
cloud-event-proxysidecar. Thecloud-event-proxysidecar container sends an acknowledgment with an ID and URL location to access the stored subscription resource. The sidecar creates an AMQ messaging listener protocol for the resource specified in the subscription. -
DU application receives the PTP event notification: The
cloud-event-proxysidecar container listens to the address specified in the resource qualifier. The DU events consumer processes the message and passes it to the return URL specified in the subscription. -
cloud-event-proxy sidecar validates the PTP event and posts it to the DU application: The
cloud-event-proxysidecar receives the event, unwraps the cloud events object to retrieve the data, and fetches the return URL to post the event back to the DU consumer application. - DU application uses the PTP event: The DU application events consumer receives and processes the PTP event.
13.7.3. Installing the AMQ messaging bus Copia collegamentoCollegamento copiato negli appunti!
To pass PTP fast event notifications between publisher and subscriber on a node, you must install and configure an AMQ messaging bus to run locally on the node. You do this by installing the AMQ Interconnect Operator for use in the cluster.
Prerequisites
-
Install the OpenShift Container Platform CLI (
oc). -
Log in as a user with
cluster-adminprivileges.
Procedure
-
Install the AMQ Interconnect Operator to its own
amq-interconnectnamespace. See Adding the Red Hat Integration - AMQ Interconnect Operator.
Verification
Check that the AMQ Interconnect Operator is available and the required pods are running:
oc get pods -n amq-interconnect
$ oc get pods -n amq-interconnectCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE amq-interconnect-645db76c76-k8ghs 1/1 Running 0 23h interconnect-operator-5cb5fc7cc-4v7qm 1/1 Running 0 23h
NAME READY STATUS RESTARTS AGE amq-interconnect-645db76c76-k8ghs 1/1 Running 0 23h interconnect-operator-5cb5fc7cc-4v7qm 1/1 Running 0 23hCopy to Clipboard Copied! Toggle word wrap Toggle overflow Check that the required
linuxptp-daemonPTP event producer pods are running in theopenshift-ptpnamespace.oc get pods -n openshift-ptp
$ oc get pods -n openshift-ptpCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE linuxptp-daemon-2t78p 3/3 Running 0 12h linuxptp-daemon-k8n88 3/3 Running 0 12h
NAME READY STATUS RESTARTS AGE linuxptp-daemon-2t78p 3/3 Running 0 12h linuxptp-daemon-k8n88 3/3 Running 0 12hCopy to Clipboard Copied! Toggle word wrap Toggle overflow
13.7.4. Configuring the PTP fast event notifications publisher Copia collegamentoCollegamento copiato negli appunti!
To start using PTP fast event notifications for a network interface in your cluster, you must enable the fast event publisher in the PTP Operator PtpOperatorConfig custom resource (CR) and configure ptpClockThreshold values in a PtpConfig CR that you create.
Prerequisites
-
Install the OpenShift Container Platform CLI (
oc). -
Log in as a user with
cluster-adminprivileges. - Install the PTP Operator and AMQ Interconnect Operator.
Procedure
Modify the default PTP Operator config to enable PTP fast events.
Save the following YAML in the
ptp-operatorconfig.yamlfile:Copy to Clipboard Copied! Toggle word wrap Toggle overflow - 1
- Set
enableEventPublishertotrueto enable PTP fast event notifications. - 2
- Set
transportHostto the AMQ router that you configured where<instance_name>and<namespace>correspond to the AMQ Interconnect router instance name and namespace, for example,amqp://amq-interconnect.amq-interconnect.svc.cluster.local
Update the
PtpOperatorConfigCR:oc apply -f ptp-operatorconfig.yaml
$ oc apply -f ptp-operatorconfig.yamlCopy to Clipboard Copied! Toggle word wrap Toggle overflow
Create a
PtpConfigcustom resource (CR) for the PTP enabled interface, and set the required values forptpClockThresholdandptp4lOpts. The following YAML illustrates the required values that you must set in thePtpConfigCR:Copy to Clipboard Copied! Toggle word wrap Toggle overflow - 1
- Append
--summary_interval -4to use PTP fast events. - 2
- Required
phc2sysOptsvalues.-mprints messages tostdout. Thelinuxptp-daemonDaemonSetparses the logs and generates Prometheus metrics. - 3
- Specify a string that contains the configuration to replace the default /etc/ptp4l.conf file. To use the default configuration, leave the field empty.
- 4
- Optional. If the
ptpClockThresholdstanza is not present, default values are used for theptpClockThresholdfields. The stanza shows defaultptpClockThresholdvalues. TheptpClockThresholdvalues configure how long after the PTP master clock is disconnected before PTP events are triggered.holdOverTimeoutis the time value in seconds before the PTP clock event state changes toFREERUNwhen the PTP master clock is disconnected. ThemaxOffsetThresholdandminOffsetThresholdsettings configure offset values in nanoseconds that compare against the values forCLOCK_REALTIME(phc2sys) or master offset (ptp4l). When theptp4lorphc2sysoffset value is outside this range, the PTP clock state is set toFREERUN. When the offset value is within this range, the PTP clock state is set toLOCKED.
13.7.5. Subscribing DU applications to PTP events REST API reference Copia collegamentoCollegamento copiato negli appunti!
Use the PTP event notifications REST API to subscribe a distributed unit (DU) application to the PTP events that are generated on the parent node.
Subscribe applications to PTP events by using the resource address /cluster/node/<node_name>/ptp, where <node_name> is the cluster node running the DU application.
Deploy your cloud-event-consumer DU application container and cloud-event-proxy sidecar container in a separate DU application pod. The cloud-event-consumer DU application subscribes to the cloud-event-proxy container in the application pod.
Use the following API endpoints to subscribe the cloud-event-consumer DU application to PTP events posted by the cloud-event-proxy container at http://localhost:8089/api/ocloudNotifications/v1/ in the DU application pod:
/api/ocloudNotifications/v1/subscriptions-
POST: Creates a new subscription -
GET: Retrieves a list of subscriptions
-
/api/ocloudNotifications/v1/subscriptions/<subscription_id>-
GET: Returns details for the specified subscription ID
-
api/ocloudNotifications/v1/subscriptions/status/<subscription_id>-
PUT: Creates a new status ping request for the specified subscription ID
-
/api/ocloudNotifications/v1/health-
GET: Returns the health status ofocloudNotificationsAPI
-
9089 is the default port for the cloud-event-consumer container deployed in the application pod. You can configure a different port for your DU application as required.
13.7.5.1. api/ocloudNotifications/v1/subscriptions Copia collegamentoCollegamento copiato negli appunti!
13.7.5.1.1. HTTP method Copia collegamentoCollegamento copiato negli appunti!
GET api/ocloudNotifications/v1/subscriptions
13.7.5.1.1.1. Description Copia collegamentoCollegamento copiato negli appunti!
Returns a list of subscriptions. If subscriptions exist, a 200 OK status code is returned along with the list of subscriptions.
Example API response
13.7.5.1.2. HTTP method Copia collegamentoCollegamento copiato negli appunti!
POST api/ocloudNotifications/v1/subscriptions
13.7.5.1.2.1. Description Copia collegamentoCollegamento copiato negli appunti!
Creates a new subscription. If a subscription is successfully created, or if it already exists, a 201 Created status code is returned.
| Parameter | Type |
|---|---|
| subscription | data |
Example payload
{
"uriLocation": "http://localhost:8089/api/ocloudNotifications/v1/subscriptions",
"resource": "/cluster/node/compute-1.example.com/ptp"
}
{
"uriLocation": "http://localhost:8089/api/ocloudNotifications/v1/subscriptions",
"resource": "/cluster/node/compute-1.example.com/ptp"
}
13.7.5.2. api/ocloudNotifications/v1/subscriptions/ Copia collegamentoCollegamento copiato negli appunti!
13.7.5.2.1. HTTP method Copia collegamentoCollegamento copiato negli appunti!
GET api/ocloudNotifications/v1/subscriptions/<subscription_id>
13.7.5.2.1.1. Description Copia collegamentoCollegamento copiato negli appunti!
Returns details for the subscription with ID <subscription_id>
| Parameter | Type |
|---|---|
|
| string |
Example API response
13.7.5.3. api/ocloudNotifications/v1/subscriptions/status/ Copia collegamentoCollegamento copiato negli appunti!
13.7.5.3.1. HTTP method Copia collegamentoCollegamento copiato negli appunti!
PUT api/ocloudNotifications/v1/subscriptions/status/<subscription_id>
13.7.5.3.1.1. Description Copia collegamentoCollegamento copiato negli appunti!
Creates a new status ping request for subscription with ID <subscription_id>. If a subscription is present, the status request is successful and a 202 Accepted status code is returned.
| Parameter | Type |
|---|---|
|
| string |
Example API response
{"status":"ping sent"}
{"status":"ping sent"}
13.7.5.4. api/ocloudNotifications/v1/health/ Copia collegamentoCollegamento copiato negli appunti!
13.7.5.4.1. HTTP method Copia collegamentoCollegamento copiato negli appunti!
GET api/ocloudNotifications/v1/health/
13.7.5.4.1.1. Description Copia collegamentoCollegamento copiato negli appunti!
Returns the health status for the ocloudNotifications REST API.
Example API response
OK
OK
13.7.6. Monitoring PTP fast event metrics using the CLI Copia collegamentoCollegamento copiato negli appunti!
You can monitor fast events bus metrics directly from cloud-event-proxy containers using the oc CLI.
PTP fast event notification metrics are also available in the OpenShift Container Platform web console.
Prerequisites
-
Install the OpenShift Container Platform CLI (
oc). -
Log in as a user with
cluster-adminprivileges. - Install and configure the PTP Operator.
Procedure
Get the list of active
linuxptp-daemonpods.oc get pods -n openshift-ptp
$ oc get pods -n openshift-ptpCopy to Clipboard Copied! Toggle word wrap Toggle overflow Example output
NAME READY STATUS RESTARTS AGE linuxptp-daemon-2t78p 3/3 Running 0 8h linuxptp-daemon-k8n88 3/3 Running 0 8h
NAME READY STATUS RESTARTS AGE linuxptp-daemon-2t78p 3/3 Running 0 8h linuxptp-daemon-k8n88 3/3 Running 0 8hCopy to Clipboard Copied! Toggle word wrap Toggle overflow Access the metrics for the required
cloud-event-proxycontainer by running the following command:oc exec -it <linuxptp-daemon> -n openshift-ptp -c cloud-event-proxy -- curl 127.0.0.1:9091/metrics
$ oc exec -it <linuxptp-daemon> -n openshift-ptp -c cloud-event-proxy -- curl 127.0.0.1:9091/metricsCopy to Clipboard Copied! Toggle word wrap Toggle overflow where:
- <linuxptp-daemon>
Specifies the pod you want to query, for example,
linuxptp-daemon-2t78p.Example output
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
13.7.7. Monitoring PTP fast event metrics in the web console Copia collegamentoCollegamento copiato negli appunti!
You can monitor PTP fast event metrics in the OpenShift Container Platform web console by using the pre-configured and self-updating Prometheus monitoring stack.
Prerequisites
-
Install the OpenShift Container Platform CLI
oc. -
Log in as a user with
cluster-adminprivileges.
Procedure
Enter the following command to return the list of available PTP metrics from the
cloud-event-proxysidecar container:oc exec -it <linuxptp_daemon_pod> -n openshift-ptp -c cloud-event-proxy -- curl 127.0.0.1:9091/metrics
$ oc exec -it <linuxptp_daemon_pod> -n openshift-ptp -c cloud-event-proxy -- curl 127.0.0.1:9091/metricsCopy to Clipboard Copied! Toggle word wrap Toggle overflow where:
- <linuxptp_daemon_pod>
-
Specifies the pod you want to query, for example,
linuxptp-daemon-2t78p.
-
Copy the name of the PTP metric you want to query from the list of returned metrics, for example,
cne_amqp_events_received. -
In the OpenShift Container Platform web console, click Observe
Metrics. - Paste the PTP metric into the Expression field, and click Run queries.