apiVersion: v1
kind: Namespace
metadata:
name: openshift-ptp
annotations:
workload.openshift.io/allowed: management
labels:
name: openshift-ptp
openshift.io/cluster-monitoring: "true"
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. |
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 linuxptp
services.
Notification of PTP clock events that negatively affect the performance and reliability of your application with the PTP Operator cloud-event-proxy
sidecar.
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).
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:
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.
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.
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.
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 ( |
As a cluster administrator, you can install the Operator by using the CLI.
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-admin
privileges.
Create a namespace for the PTP Operator.
Save the following YAML in the ptp-namespace.yaml
file:
apiVersion: v1
kind: Namespace
metadata:
name: openshift-ptp
annotations:
workload.openshift.io/allowed: management
labels:
name: openshift-ptp
openshift.io/cluster-monitoring: "true"
Create the Namespace
CR:
$ oc create -f ptp-namespace.yaml
Create an Operator group for the PTP Operator.
Save the following YAML in the ptp-operatorgroup.yaml
file:
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
name: ptp-operators
namespace: openshift-ptp
spec:
targetNamespaces:
- openshift-ptp
Create the OperatorGroup
CR:
$ oc create -f ptp-operatorgroup.yaml
Subscribe to the PTP Operator.
Save the following YAML in the ptp-sub.yaml
file:
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
name: ptp-operator-subscription
namespace: openshift-ptp
spec:
channel: "stable"
name: ptp-operator
source: redhat-operators
sourceNamespace: openshift-marketplace
Create the Subscription
CR:
$ oc create -f ptp-sub.yaml
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
Name Phase
4.10.0-202201261535 Succeeded
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. |
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.
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.
During 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-ptp
project.
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.
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
apiVersion: v1
items:
- apiVersion: ptp.openshift.io/v1
kind: NodePtpDevice
metadata:
creationTimestamp: "2022-01-27T15:16:28Z"
generation: 1
name: dev-worker-0 (1)
namespace: openshift-ptp
resourceVersion: "6538103"
uid: d42fc9ad-bcbf-4590-b6d8-b676c642781a
spec: {}
status:
devices: (2)
- name: eno1
- name: eno2
- name: eno3
- name: eno4
- name: enp5s0f0
- name: enp5s0f1
...
1 | The value for the name parameter is the same as the name of the parent node. |
2 | The devices collection includes a list of the PTP capable devices that the PTP Operator discovers for the node. |
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 |
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-admin
privileges.
Install the PTP Operator.
Create the PtpConfig
resource. For example:
Save the following YAML in the grandmaster-clock-ptp-config.yaml
file:
apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
name: grandmaster-clock
namespace: openshift-ptp
annotations: {}
spec:
profile:
- name: grandmaster-clock
# The interface name is hardware-specific
interface: $interface
ptp4lOpts: "-2"
phc2sysOpts: "-a -r -r -n 24"
ptpSchedulingPolicy: SCHED_FIFO
ptpSchedulingPriority: 10
ptpSettings:
logReduce: "true"
ptp4lConf: |
[global]
#
# Default Data Set
#
twoStepFlag 1
slaveOnly 0
priority1 128
priority2 128
domainNumber 24
#utc_offset 37
clockClass 255
clockAccuracy 0xFE
offsetScaledLogVariance 0xFFFF
free_running 0
freq_est_interval 1
dscp_event 0
dscp_general 0
dataset_comparison G.8275.x
G.8275.defaultDS.localPriority 128
#
# Port Data Set
#
logAnnounceInterval -3
logSyncInterval -4
logMinDelayReqInterval -4
logMinPdelayReqInterval -4
announceReceiptTimeout 3
syncReceiptTimeout 0
delayAsymmetry 0
fault_reset_interval -4
neighborPropDelayThresh 20000000
masterOnly 0
G.8275.portDS.localPriority 128
#
# Run time options
#
assume_two_step 0
logging_level 6
path_trace_enabled 0
follow_up_info 0
hybrid_e2e 0
inhibit_multicast_service 0
net_sync_monitor 0
tc_spanning_tree 0
tx_timestamp_timeout 50
unicast_listen 0
unicast_master_table 0
unicast_req_duration 3600
use_syslog 1
verbose 0
summary_interval 0
kernel_leap 1
check_fup_sync 0
clock_class_threshold 7
#
# Servo Options
#
pi_proportional_const 0.0
pi_integral_const 0.0
pi_proportional_scale 0.0
pi_proportional_exponent -0.3
pi_proportional_norm_max 0.7
pi_integral_scale 0.0
pi_integral_exponent 0.4
pi_integral_norm_max 0.3
step_threshold 2.0
first_step_threshold 0.00002
max_frequency 900000000
clock_servo pi
sanity_freq_limit 200000000
ntpshm_segment 0
#
# Transport options
#
transportSpecific 0x0
ptp_dst_mac 01:1B:19:00:00:00
p2p_dst_mac 01:80:C2:00:00:0E
udp_ttl 1
udp6_scope 0x0E
uds_address /var/run/ptp4l
#
# Default interface options
#
clock_type OC
network_transport L2
delay_mechanism E2E
time_stamping hardware
tsproc_mode filter
delay_filter moving_median
delay_filter_length 10
egressLatency 0
ingressLatency 0
boundary_clock_jbod 0
#
# Clock description
#
productDescription ;;
revisionData ;;
manufacturerIdentity 00:00:00
userDescription ;
timeSource 0xA0
recommend:
- profile: grandmaster-clock
priority: 4
match:
- nodeLabel: "node-role.kubernetes.io/$mcp"
Create the CR by running the following command:
$ oc create -f grandmaster-clock-ptp-config.yaml
Check that the PtpConfig
profile is applied to the node.
Get the list of pods in the openshift-ptp
namespace by running the following command:
$ oc get pods -n openshift-ptp -o wide
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
Check that the profile is correct. Examine the logs of the linuxptp
daemon that corresponds to the node you specified in the PtpConfig
profile.
Run the following command:
$ oc logs linuxptp-daemon-74m2g -n openshift-ptp -c linuxptp-daemon-container
ts2phc[94980.334]: [ts2phc.0.config] nmea delay: 98690975 ns
ts2phc[94980.334]: [ts2phc.0.config] ens3f0 extts index 0 at 1676577329.999999999 corr 0 src 1676577330.901342528 diff -1
ts2phc[94980.334]: [ts2phc.0.config] ens3f0 master offset -1 s2 freq -1
ts2phc[94980.441]: [ts2phc.0.config] nmea sentence: GNRMC,195453.00,A,4233.24427,N,07126.64420,W,0.008,,160223,,,A,V
phc2sys[94980.450]: [ptp4l.0.config] CLOCK_REALTIME phc offset 943 s2 freq -89604 delay 504
phc2sys[94980.512]: [ptp4l.0.config] CLOCK_REALTIME phc offset 1000 s2 freq -89264 delay 474
You can configure linuxptp
services (ptp4l
, phc2sys
) as ordinary clock by creating a PtpConfig
custom resource (CR) object.
Use the following example |
Install the OpenShift CLI (oc
).
Log in as a user with cluster-admin
privileges.
Install the PTP Operator.
Create the following PtpConfig
CR, and then save the YAML in the ordinary-clock-ptp-config.yaml
file.
apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
name: ordinary-clock
namespace: openshift-ptp
annotations: {}
spec:
profile:
- name: ordinary-clock
# The interface name is hardware-specific
interface: $interface
ptp4lOpts: "-2 -s"
phc2sysOpts: "-a -r -n 24"
ptpSchedulingPolicy: SCHED_FIFO
ptpSchedulingPriority: 10
ptpSettings:
logReduce: "true"
ptp4lConf: |
[global]
#
# Default Data Set
#
twoStepFlag 1
slaveOnly 1
priority1 128
priority2 128
domainNumber 24
#utc_offset 37
clockClass 255
clockAccuracy 0xFE
offsetScaledLogVariance 0xFFFF
free_running 0
freq_est_interval 1
dscp_event 0
dscp_general 0
dataset_comparison G.8275.x
G.8275.defaultDS.localPriority 128
#
# Port Data Set
#
logAnnounceInterval -3
logSyncInterval -4
logMinDelayReqInterval -4
logMinPdelayReqInterval -4
announceReceiptTimeout 3
syncReceiptTimeout 0
delayAsymmetry 0
fault_reset_interval -4
neighborPropDelayThresh 20000000
masterOnly 0
G.8275.portDS.localPriority 128
#
# Run time options
#
assume_two_step 0
logging_level 6
path_trace_enabled 0
follow_up_info 0
hybrid_e2e 0
inhibit_multicast_service 0
net_sync_monitor 0
tc_spanning_tree 0
tx_timestamp_timeout 50
unicast_listen 0
unicast_master_table 0
unicast_req_duration 3600
use_syslog 1
verbose 0
summary_interval 0
kernel_leap 1
check_fup_sync 0
clock_class_threshold 7
#
# Servo Options
#
pi_proportional_const 0.0
pi_integral_const 0.0
pi_proportional_scale 0.0
pi_proportional_exponent -0.3
pi_proportional_norm_max 0.7
pi_integral_scale 0.0
pi_integral_exponent 0.4
pi_integral_norm_max 0.3
step_threshold 2.0
first_step_threshold 0.00002
max_frequency 900000000
clock_servo pi
sanity_freq_limit 200000000
ntpshm_segment 0
#
# Transport options
#
transportSpecific 0x0
ptp_dst_mac 01:1B:19:00:00:00
p2p_dst_mac 01:80:C2:00:00:0E
udp_ttl 1
udp6_scope 0x0E
uds_address /var/run/ptp4l
#
# Default interface options
#
clock_type OC
network_transport L2
delay_mechanism E2E
time_stamping hardware
tsproc_mode filter
delay_filter moving_median
delay_filter_length 10
egressLatency 0
ingressLatency 0
boundary_clock_jbod 0
#
# Clock description
#
productDescription ;;
revisionData ;;
manufacturerIdentity 00:00:00
userDescription ;
timeSource 0xA0
recommend:
- profile: ordinary-clock
priority: 4
match:
- nodeLabel: "node-role.kubernetes.io/$mcp"
Custom resource field | Description |
---|---|
|
The name of the |
|
Specify an array of one or more |
|
Specify the network interface to be used by the |
|
Specify system config options for the |
|
Specify system config options for the |
|
Specify a string that contains the configuration to replace the default |
|
For Intel Columbiaville 800 Series NICs, set |
|
For Intel Columbiaville 800 Series NICs, set |
|
Scheduling policy for |
|
Integer value from 1-65 used to set FIFO priority for |
|
Optional. If |
|
Specify an array of one or more |
|
Specify the |
|
Set |
|
Specify |
|
Update |
|
Update |
Create the PtpConfig
CR by running the following command:
$ oc create -f ordinary-clock-ptp-config.yaml
Check that the PtpConfig
profile is applied to the node.
Get the list of pods in the openshift-ptp
namespace by running the following command:
$ oc get pods -n openshift-ptp -o wide
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
Check that the profile is correct. Examine the logs of the linuxptp
daemon that corresponds to the node you specified in the PtpConfig
profile. Run the following command:
$ oc logs linuxptp-daemon-4xkbb -n openshift-ptp -c linuxptp-daemon-container
I1115 09:41:17.117596 4143292 daemon.go:107] in applyNodePTPProfile
I1115 09:41:17.117604 4143292 daemon.go:109] updating NodePTPProfile to:
I1115 09:41:17.117607 4143292 daemon.go:110] ------------------------------------
I1115 09:41:17.117612 4143292 daemon.go:102] Profile Name: profile1
I1115 09:41:17.117616 4143292 daemon.go:102] Interface: ens787f1
I1115 09:41:17.117620 4143292 daemon.go:102] Ptp4lOpts: -2 -s
I1115 09:41:17.117623 4143292 daemon.go:102] Phc2sysOpts: -a -r -n 24
I1115 09:41:17.117626 4143292 daemon.go:116] ------------------------------------
For more information about FIFO priority scheduling on PTP hardware, see Configuring FIFO priority scheduling for PTP hardware.
For more information about configuring PTP fast events, see Configuring the PTP fast event notifications publisher.
You can configure the linuxptp
services (ptp4l
, phc2sys
) as boundary clock by creating a PtpConfig
custom resource (CR) object.
Use the following example |
Install the OpenShift CLI (oc
).
Log in as a user with cluster-admin
privileges.
Install the PTP Operator.
Create the following PtpConfig
CR, and then save the YAML in the boundary-clock-ptp-config.yaml
file.
apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
name: boundary-clock
namespace: openshift-ptp
annotations: {}
spec:
profile:
- name: boundary-clock
ptp4lOpts: "-2"
phc2sysOpts: "-a -r -n 24"
ptpSchedulingPolicy: SCHED_FIFO
ptpSchedulingPriority: 10
ptpSettings:
logReduce: "true"
ptp4lConf: |
# The interface name is hardware-specific
[$iface_slave]
masterOnly 0
[$iface_master_1]
masterOnly 1
[$iface_master_2]
masterOnly 1
[$iface_master_3]
masterOnly 1
[global]
#
# Default Data Set
#
twoStepFlag 1
slaveOnly 0
priority1 128
priority2 128
domainNumber 24
#utc_offset 37
clockClass 248
clockAccuracy 0xFE
offsetScaledLogVariance 0xFFFF
free_running 0
freq_est_interval 1
dscp_event 0
dscp_general 0
dataset_comparison G.8275.x
G.8275.defaultDS.localPriority 128
#
# Port Data Set
#
logAnnounceInterval -3
logSyncInterval -4
logMinDelayReqInterval -4
logMinPdelayReqInterval -4
announceReceiptTimeout 3
syncReceiptTimeout 0
delayAsymmetry 0
fault_reset_interval -4
neighborPropDelayThresh 20000000
masterOnly 0
G.8275.portDS.localPriority 128
#
# Run time options
#
assume_two_step 0
logging_level 6
path_trace_enabled 0
follow_up_info 0
hybrid_e2e 0
inhibit_multicast_service 0
net_sync_monitor 0
tc_spanning_tree 0
tx_timestamp_timeout 50
unicast_listen 0
unicast_master_table 0
unicast_req_duration 3600
use_syslog 1
verbose 0
summary_interval 0
kernel_leap 1
check_fup_sync 0
clock_class_threshold 135
#
# Servo Options
#
pi_proportional_const 0.0
pi_integral_const 0.0
pi_proportional_scale 0.0
pi_proportional_exponent -0.3
pi_proportional_norm_max 0.7
pi_integral_scale 0.0
pi_integral_exponent 0.4
pi_integral_norm_max 0.3
step_threshold 2.0
first_step_threshold 0.00002
max_frequency 900000000
clock_servo pi
sanity_freq_limit 200000000
ntpshm_segment 0
#
# Transport options
#
transportSpecific 0x0
ptp_dst_mac 01:1B:19:00:00:00
p2p_dst_mac 01:80:C2:00:00:0E
udp_ttl 1
udp6_scope 0x0E
uds_address /var/run/ptp4l
#
# Default interface options
#
clock_type BC
network_transport L2
delay_mechanism E2E
time_stamping hardware
tsproc_mode filter
delay_filter moving_median
delay_filter_length 10
egressLatency 0
ingressLatency 0
boundary_clock_jbod 0
#
# Clock description
#
productDescription ;;
revisionData ;;
manufacturerIdentity 00:00:00
userDescription ;
timeSource 0xA0
recommend:
- profile: boundary-clock
priority: 4
match:
- nodeLabel: "node-role.kubernetes.io/$mcp"
Custom resource field | Description |
---|---|
|
The name of the |
|
Specify an array of one or more |
|
Specify the name of a profile object which uniquely identifies a profile object. |
|
Specify system config options for the |
|
Specify the required configuration to start |
|
The interface that receives the synchronization clock. |
|
The interface that sends the synchronization clock. |
|
For Intel Columbiaville 800 Series NICs, set |
|
For Intel Columbiaville 800 Series NICs, ensure |
|
Specify system config options for the |
|
Scheduling policy for ptp4l and phc2sys processes. Default value is |
|
Integer value from 1-65 used to set FIFO priority for |
|
Optional. If |
|
Specify an array of one or more |
|
Specify the |
|
Specify the |
|
Specify |
|
Update |
|
Update |
Create the CR by running the following command:
$ oc create -f boundary-clock-ptp-config.yaml
Check that the PtpConfig
profile is applied to the node.
Get the list of pods in the openshift-ptp
namespace by running the following command:
$ oc get pods -n openshift-ptp -o wide
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
Check that the profile is correct. Examine the logs of the linuxptp
daemon that corresponds to the node you specified in the PtpConfig
profile. Run the following command:
$ oc logs linuxptp-daemon-4xkbb -n openshift-ptp -c linuxptp-daemon-container
I1115 09:41:17.117596 4143292 daemon.go:107] in applyNodePTPProfile
I1115 09:41:17.117604 4143292 daemon.go:109] updating NodePTPProfile to:
I1115 09:41:17.117607 4143292 daemon.go:110] ------------------------------------
I1115 09:41:17.117612 4143292 daemon.go:102] Profile Name: profile1
I1115 09:41:17.117616 4143292 daemon.go:102] Interface:
I1115 09:41:17.117620 4143292 daemon.go:102] Ptp4lOpts: -2
I1115 09:41:17.117623 4143292 daemon.go:102] Phc2sysOpts: -a -r -n 24
I1115 09:41:17.117626 4143292 daemon.go:116] ------------------------------------
For more information about FIFO priority scheduling on PTP hardware, see Configuring FIFO priority scheduling for PTP hardware.
For more information about configuring PTP fast events, see Configuring the PTP fast event notifications publisher.
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 |
For a complete example CR that configures linuxptp
services as an ordinary clock with PTP fast events, see Configuring linuxptp services as ordinary clock.
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 |
Edit the PtpConfig
CR profile:
$ oc edit PtpConfig -n openshift-ptp
Change the ptpSchedulingPolicy
and ptpSchedulingPriority
fields:
apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
name: <ptp_config_name>
namespace: openshift-ptp
...
spec:
profile:
- name: "profile1"
...
ptpSchedulingPolicy: SCHED_FIFO (1)
ptpSchedulingPriority: 10 (2)
1 | Scheduling policy for ptp4l and phc2sys processes. Use SCHED_FIFO on systems that support FIFO scheduling. |
2 | Required. Sets the integer value 1-65 used to configure FIFO priority for ptp4l and phc2sys processes. |
Save and exit to apply the changes to the PtpConfig
CR.
Get the name of the linuxptp-daemon
pod and corresponding node where the PtpConfig
CR has been applied:
$ oc get pods -n openshift-ptp -o wide
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
Check that the ptp4l
process is running with the updated chrt
FIFO priority:
$ oc -n openshift-ptp logs linuxptp-daemon-lgm55 -c linuxptp-daemon-container|grep chrt
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
Troubleshoot common problems with the PTP Operator by performing the following steps.
Install the OpenShift Container Platform CLI (oc
).
Log in as a user with cluster-admin
privileges.
Install the PTP Operator on a bare-metal cluster with hosts that support PTP.
Check the Operator and operands are successfully deployed in the cluster for the configured nodes.
$ oc get pods -n openshift-ptp -o wide
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
When the PTP fast event bus is enabled, the number of ready |
Check that supported hardware is found in the cluster.
$ oc -n openshift-ptp get nodeptpdevices.ptp.openshift.io
NAME AGE
control-plane-0.example.com 10d
control-plane-1.example.com 10d
compute-0.example.com 10d
compute-1.example.com 10d
compute-2.example.com 10d
Check the available PTP network interfaces for a node:
$ oc -n openshift-ptp get nodeptpdevices.ptp.openshift.io <node_name> -o yaml
where:
Specifies the node you want to query, for example, compute-0.example.com
.
apiVersion: ptp.openshift.io/v1
kind: NodePtpDevice
metadata:
creationTimestamp: "2021-09-14T16:52:33Z"
generation: 1
name: compute-0.example.com
namespace: openshift-ptp
resourceVersion: "177400"
uid: 30413db0-4d8d-46da-9bef-737bacd548fd
spec: {}
status:
devices:
- name: eno1
- name: eno2
- name: eno3
- name: eno4
- name: enp5s0f0
- name: enp5s0f1
Check that the PTP interface is successfully synchronized to the primary clock by accessing the linuxptp-daemon
pod for the corresponding node.
Get the name of the linuxptp-daemon
pod and corresponding node you want to troubleshoot by running the following command:
$ oc get pods -n openshift-ptp -o wide
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
Remote shell into the required linuxptp-daemon
container:
$ oc rsh -n openshift-ptp -c linuxptp-daemon-container <linux_daemon_container>
where:
is the container you want to diagnose, for example linuxptp-daemon-lmvgn
.
In the remote shell connection to the linuxptp-daemon
container, use the PTP Management Client (pmc
) tool to diagnose the network interface. Run the following pmc
command to check the sync status of the PTP device, for example ptp4l
.
# pmc -u -f /var/run/ptp4l.0.config -b 0 'GET PORT_DATA_SET'
sending: GET PORT_DATA_SET
40a6b7.fffe.166ef0-1 seq 0 RESPONSE MANAGEMENT PORT_DATA_SET
portIdentity 40a6b7.fffe.166ef0-1
portState SLAVE
logMinDelayReqInterval -4
peerMeanPathDelay 0
logAnnounceInterval -3
announceReceiptTimeout 3
logSyncInterval -4
delayMechanism 1
logMinPdelayReqInterval -4
versionNumber 2
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. |
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. |
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:
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-proxy
sidecar to create a PTP events subscription. The cloud-event-proxy
sidecar creates a subscription resource.
cloud-event-proxy sidecar creates the subscription: The event resource is persisted by the cloud-event-proxy
sidecar. The cloud-event-proxy
sidecar 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-proxy
sidecar 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-proxy
sidecar 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.
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.
Install the OpenShift Container Platform CLI (oc
).
Log in as a user with cluster-admin
privileges.
Install the AMQ Interconnect Operator to its own amq-interconnect
namespace. See Adding the Red Hat Integration - AMQ Interconnect Operator.
Check that the AMQ Interconnect Operator is available and the required pods are running:
$ oc get pods -n amq-interconnect
NAME READY STATUS RESTARTS AGE
amq-interconnect-645db76c76-k8ghs 1/1 Running 0 23h
interconnect-operator-5cb5fc7cc-4v7qm 1/1 Running 0 23h
Check that the required linuxptp-daemon
PTP event producer pods are running in the openshift-ptp
namespace.
$ oc get pods -n openshift-ptp
NAME READY STATUS RESTARTS AGE
linuxptp-daemon-2t78p 3/3 Running 0 12h
linuxptp-daemon-k8n88 3/3 Running 0 12h
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.
Install the OpenShift Container Platform CLI (oc
).
Log in as a user with cluster-admin
privileges.
Install the PTP Operator and AMQ Interconnect Operator.
Modify the default PTP Operator config to enable PTP fast events.
Save the following YAML in the ptp-operatorconfig.yaml
file:
apiVersion: ptp.openshift.io/v1
kind: PtpOperatorConfig
metadata:
name: default
namespace: openshift-ptp
spec:
daemonNodeSelector:
node-role.kubernetes.io/worker: ""
ptpEventConfig:
enableEventPublisher: true (1)
transportHost: amqp://<instance_name>.<namespace>.svc.cluster.local (2)
1 | Set enableEventPublisher to true to enable PTP fast event notifications. |
2 | Set transportHost to 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 PtpOperatorConfig
CR:
$ oc apply -f ptp-operatorconfig.yaml
Create a PtpConfig
custom resource (CR) for the PTP enabled interface, and set the required values for ptpClockThreshold
and ptp4lOpts
. The following YAML illustrates the required values that you must set in the PtpConfig
CR:
spec:
profile:
- name: "profile1"
interface: "enp5s0f0"
ptp4lOpts: "-2 -s --summary_interval -4" (1)
phc2sysOpts: "-a -r -m -n 24 -N 8 -R 16" (2)
ptp4lConf: "" (3)
ptpClockThreshold: (4)
holdOverTimeout: 5
maxOffsetThreshold: 100
minOffsetThreshold: -100
1 | Append --summary_interval -4 to use PTP fast events. |
2 | Required phc2sysOpts values. -m prints messages to stdout . The linuxptp-daemon DaemonSet parses 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 ptpClockThreshold stanza is not present, default values are used for the ptpClockThreshold fields. The stanza shows default ptpClockThreshold values. The ptpClockThreshold values configure how long after the PTP master clock is disconnected before PTP events are triggered. holdOverTimeout is the time value in seconds before the PTP clock event state changes to FREERUN when the PTP master clock is disconnected. The maxOffsetThreshold and minOffsetThreshold settings configure offset values in nanoseconds that compare against the values for CLOCK_REALTIME (phc2sys ) or master offset (ptp4l ). When the ptp4l or phc2sys offset value is outside this range, the PTP clock state is set to FREERUN . When the offset value is within this range, the PTP clock state is set to LOCKED . |
For a complete example CR that configures linuxptp
services as an ordinary clock with PTP fast events, see Configuring linuxptp services as ordinary clock.
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 of ocloudNotifications
API
|
GET api/ocloudNotifications/v1/subscriptions
Returns a list of subscriptions. If subscriptions exist, a 200 OK
status code is returned along with the list of subscriptions.
[
{
"id": "75b1ad8f-c807-4c23-acf5-56f4b7ee3826",
"endpointUri": "http://localhost:9089/event",
"uriLocation": "http://localhost:8089/api/ocloudNotifications/v1/subscriptions/75b1ad8f-c807-4c23-acf5-56f4b7ee3826",
"resource": "/cluster/node/compute-1.example.com/ptp"
}
]
POST api/ocloudNotifications/v1/subscriptions
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 |
{
"uriLocation": "http://localhost:8089/api/ocloudNotifications/v1/subscriptions",
"resource": "/cluster/node/compute-1.example.com/ptp"
}
GET api/ocloudNotifications/v1/subscriptions/<subscription_id>
Returns details for the subscription with ID <subscription_id>
Parameter | Type |
---|---|
|
string |
{
"id":"48210fb3-45be-4ce0-aa9b-41a0e58730ab",
"endpointUri": "http://localhost:9089/event",
"uriLocation":"http://localhost:8089/api/ocloudNotifications/v1/subscriptions/48210fb3-45be-4ce0-aa9b-41a0e58730ab",
"resource":"/cluster/node/compute-1.example.com/ptp"
}
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. |
Install the OpenShift Container Platform CLI (oc
).
Log in as a user with cluster-admin
privileges.
Install and configure the PTP Operator.
Get the list of active linuxptp-daemon
pods.
$ oc get pods -n openshift-ptp
NAME READY STATUS RESTARTS AGE
linuxptp-daemon-2t78p 3/3 Running 0 8h
linuxptp-daemon-k8n88 3/3 Running 0 8h
Access the metrics for the required cloud-event-proxy
container by running the following command:
$ oc exec -it <linuxptp-daemon> -n openshift-ptp -c cloud-event-proxy -- curl 127.0.0.1:9091/metrics
where:
Specifies the pod you want to query, for example, linuxptp-daemon-2t78p
.
# HELP cne_amqp_events_published Metric to get number of events published by the transport
# TYPE cne_amqp_events_published gauge
cne_amqp_events_published{address="/cluster/node/compute-1.example.com/ptp/status",status="success"} 1041
# HELP cne_amqp_events_received Metric to get number of events received by the transport
# TYPE cne_amqp_events_received gauge
cne_amqp_events_received{address="/cluster/node/compute-1.example.com/ptp",status="success"} 1019
# HELP cne_amqp_receiver Metric to get number of receiver created
# TYPE cne_amqp_receiver gauge
cne_amqp_receiver{address="/cluster/node/mock",status="active"} 1
cne_amqp_receiver{address="/cluster/node/compute-1.example.com/ptp",status="active"} 1
cne_amqp_receiver{address="/cluster/node/compute-1.example.com/redfish/event",status="active"}
...
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.
Install the OpenShift Container Platform CLI oc
.
Log in as a user with cluster-admin
privileges.
Enter the following command to return the list of available PTP metrics from the cloud-event-proxy
sidecar container:
$ oc exec -it <linuxptp_daemon_pod> -n openshift-ptp -c cloud-event-proxy -- curl 127.0.0.1:9091/metrics
where:
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.