Model-Driven Telemetry

About Telemetry

Collecting data for analyzing and troubleshooting has always been an important aspect in monitoring the health of a network.

Cisco NX-OS provides several mechanisms such as SNMP, CLI, and Syslog to collect data from a network. These mechanisms have limitations that restrict automation and scale. One limitation is the use of the pull model, where the initial request for data from network elements originates from the client. The pull model does not scale when there is more than one network management station (NMS) in the network. With this model, the server sends data only when clients request it. To initiate such requests, continual manual intervention is required. This continual manual intervention makes the pull model inefficient.

A push model continuously streams data out of the network and notifies the client. Telemetry enables the push model, which provides near-real-time access to monitoring data.

Telemetry Components and Process

Telemetry consists of four key elements:

  • Data Collection — Telemetry data is collected from the Data Management Engine (DME) database in branches of the object model specified using distinguished name (DN) paths. The data can be retrieved periodically (frequency-based) or only when a change occurs in any object on a specified path (event-based). You can use the NX-API to collect frequency-based data.

  • Data Encoding — The telemetry encoder encapsulates the collected data into the desired format for transporting.

    NX-OS encodes telemetry data in the Google Protocol Buffers (GPB) and JSON format.

  • Data Transport — NX-OS transports telemetry data using HTTP for JSON encoding and the Google remote procedure call (gRPC) protocol for GPB encoding. The gRPC receiver supports message sizes greater than 4MB. (Telemetry data using HTTPS is also supported if a certificate is configured.)

    Starting with Cisco Nexus 9.2(1), UDP and secure UDP (DTLS) are supported as telemetry transport protocols. You can add destinations that receive UDP. The encoding for UDP and secure UDP can be GPB or JSON.

    Use the following command to configure the UDP transport to stream data using a datagram socket either in JSON or GPB:
    
destination-group num
  ip address xxx.xxx.xxx.xxx port xxxx protocol UDP encoding {JSON | GPB }

    Where num is a number between 1 and 4095.

    Example for IPv4 destination: 
    
destination-group 100
  ip address 171.70.55.69 port 50001 protocol UDP encoding GPB
    The UDP telemetry will be sent with the following header:
    
typedef enum tm_encode_ {
  TM_ENCODE_DUMMY, 
  TM_ENCODE_GPB, 
  TM_ENCODE_JSON, 
  TM_ENCODE_XML, 
  TM_ENCODE_MAX, 
} tm_encode_type_t; 

typedef struct tm_pak_hdr_ { 
  uint8_t version; /* 1 */ 
  uint8_t encoding; 
  uint16_t msg_size; 
  uint8_t secure; 
  uint8_t padding; 
}__attribute__ ((packed, aligned (1))) tm_pak_hdr_t;

    Use the first 6 bytes in the payload to successfully process telemetry data using UDP, using one of the following methods:

    • Read the information in the header to determine which decoder to use to decode the data, JSON or GPB, if the receiver is meant to receive different types of data from multiple end points, or

    • Remove the header if you are expecting one decoder (JSON or GPB) but not the other


    Note

    Depending on the receiving operation system and the network load, using the UDP protocol may result in packet drops.

  • Telemetry Receiver — A telemetry receiver is a remote management system or application that stores the telemetry data.

The GPB encoder stores data in a generic key-value format. The encoder requires metadata in the form of a compiled .proto file to translate the data into GPB format.

In order to correctly receive and decode the data stream, the receiver requires the .proto file that describes the encoding and the transport services. The encoding decodes the binary stream into a key value string pair.

A telemetry .proto file that describes the GPB encoding and gRPC transport is available on Cisco's GitLab: https://github.com/CiscoDevNet/nx-telemetry-proto

High Availability of the Telemetry Process

High availability of the telemetry process is supported with the following behaviors:

  • System Reload — During a system reload, any telemetry configuration and streaming services are restored.

  • Process Restart — If the telemetry process freezes or restarts for any reason, configuration and streaming services are restored when telemetry is restarted.

Licensing Requirements for Telemetry

Product

License Requirement

Cisco NX-OS

Telemetry requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS image and is provided at no extra charge to you. For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.

Installing and Upgrading Telemetry

Installing the Application

The telemetry application is packaged as a feature RPM and included with the NX-OS release. The RPM is installed by default as part of the image bootup. After installation, you can start the application using the feature telemetry command. The RPM file is located in the /rpms directory and is named as follows:

As in the following example:

Installing Incremental Updates and Fixes

Copy the RPM to the device bootflash and use the following commands from the bash prompt: 

feature bash
run bash sudo su

Then copy the RPM to the device bootflash. Use the following commands from the bash prompt: 

yum upgrade telemetry_new_version.rpm

The application is upgraded and the change appears when the application is started again.

Downgrading to a Previous Version

To downgrade the telemetry application to a previous version, use the following command from the bash prompt:
    yum downgrade telemetry

Verifying the Active Version

To verify the active version, run the following command from the switch exec prompt: 

show install active

Note
The show install active command will only show the active installed RPM after an upgrade has occurred. The default RPM that comes bundled with the NX-OS will not be displayed.

Guidelines and Limitations

Telemetry has the following configuration guidelines and limitations:

  • Telemetry is supported in Cisco NX-OS releases that support the data management engine (DME) Native Model.

  • Support is in place for DME data collection, NX-API data sources, Google protocol buffer (GPB) encoding over Google Remote Procedure Call (gRPC) transport, and JSON encoding over HTTP.

  • The smallest sending interval (cadence) supported is five seconds for a depth of 0. The minimum cadence values for depth values greater than 0 depends on the size of the data being streamed out. Configuring cadences below the minimum value may result in undesirable system behavior.

  • Up to five remote management receivers (destinations) are supported. Configuring more than five remote receivers may result in undesirable system behavior.

  • In the event that a telemetry receiver goes down, other receivers will see data flow interrupted. The failed receiver must be restarted. Then start a new connection with the switch by unconfiguring then reconfiguring the failer receiver's IP address under the destination group.

  • Telemetry can consume up to 20% of the CPU resource.

  • To configure SSL certificate based authentication and the encryption of streamed data, you can provide a self signed SSL certificate with certificate ssl cert path hostname "CN" command.

  • QoS Explicit Congestion Notification (ECN) statistics are supported only on Cisco Nexus 9364C, 9336C-FX, and 93240YC-FX switches.

Configuration Commands After Downgrading to an Older Release

After a downgrade to an older release, some configuration commands or command options might fail because the older release may not support them. As a best practice when downgrading to an older release, unconfigure and reconfigure the telemetry feature after the new image comes up to avoid the failure of unsupported commands or command options.

The following example shows this procedure:

  • Copy the telemetry configuration to a file: 
    
switch# show running-config | section telemetry
feature telemetry
telemetry
  destination-group 100
    ip address 1.2.3.4 port 50004 protocol gRPC encoding GPB 
    use-chunking size 4096
  sensor-group 100
    path sys/bgp/inst/dom-default depth 0
  subscription 600
    dst-grp 100
    snsr-grp 100 sample-interval 7000
switch# show running-config | section telemetry > telemetry_running_config
switch# show file bootflash:telemetry_running_config
feature telemetry
telemetry
  destination-group 100
    ip address 1.2.3.4 port 50004 protocol gRPC encoding GPB 
    use-chunking size 4096
  sensor-group 100
    path sys/bgp/inst/dom-default depth 0
  subscription 600
    dst-grp 100
    snsr-grp 100 sample-interval 7000
switch#
  • Execute the downgrade operation. When the image comes up and the switch is ready, copy the telemetry configurations back to the switch: 
    
switch# copy telemetry_running_config running-config echo-commands 
`switch# config terminal`
`switch(config)# feature telemetry`
`switch(config)# telemetry`
`switch(config-telemetry)# destination-group 100`
`switch(conf-tm-dest)# ip address 1.2.3.4 port 50004 protocol gRPC encoding GPB `
`switch(conf-tm-dest)# sensor-group 100`
`switch(conf-tm-sensor)# path sys/bgp/inst/dom-default depth 0`
`switch(conf-tm-sensor)# subscription 600`
`switch(conf-tm-sub)# dst-grp 100`
`switch(conf-tm-sub)# snsr-grp 100 sample-interval 7000`
`switch(conf-tm-sub)# end`
Copy complete, now saving to disk (please wait)...
Copy complete.
switch#

gRPC Error Behavior

The switch client will disable the connection to the gRPC receiver if the gRPC receiver sends 20 errors. You will then need to unconfigure then reconfigure the receiver's IP address under the destination group to enable the gRPC receiver. Errors include:

  • The gRPC client sends the wrong certificate for secure connections,

  • The gRPC receiver takes too long to handle client messages and incurs a timeout. Avoid timeouts by processing messages using a separate message processing thread.

Telemetry Compression for gRPC Transport

Telemetry compression support is available for gRPC transport. You can use the use-compression gzip command to enable compression. (Disable compression with the no use-compression gzip command.)

The following example enables compression: 


switch(config)# telemetry
switch(config-telemetry)# destination-profile 
switch(config-tm-dest-profile)# use-compression gzip

The following example shows compression is enabled: 


switch(conf-tm-dest)# show telemetry transport 0 stats
 
Session Id:                    0                   
Connection Stats                                   
   Connection Count            0                   
   Last Connected:             Never               
   Disconnect Count            0                   
   Last Disconnected:          Never               
Transmission Stats                                 
   Compression:                gzip                
   Source Interface:           loopback1(1.1.3.4)  
   Transmit Count:             0                   
   Last TX time:               None                
   Min Tx Time:                0                   ms
   Max Tx Time:                0                   ms
   Avg Tx Time:                0                   ms
   Cur Tx Time:                0                   ms
 

switch2(config-if)# show telemetry transport 0 stats 

Session Id: 0 
Connection Stats 
Connection Count 0 
Last Connected: Never 
Disconnect Count 0 
Last Disconnected: Never 
Transmission Stats 
Compression: disabled 
Source Interface: loopback1(1.1.3.4)
Transmit Count: 0 
Last TX time: None 
Min Tx Time: 0 ms
Max Tx Time: 0 ms
Avg Tx Time: 0 ms
Cur Tx Time: 0 ms
switch2(config-if)#
The following is an example of use-compression as a POST payload: 

{
              "telemetryDestProfile": {
                "attributes": {
                  "adminSt": "enabled"
                },
                "children": [
                  {
                    "telemetryDestOptCompression": {
                      "attributes": {
                        "name": "gzip"
                      }
                    }
                  } 
                ]
              }
            }

Support for gRPC Chunking

Starting with Release 9.2(1), support for gRPC chunking has been added. For streaming to occur successfully, you must enable chunking if gRPC has to send an amount of data greater than 12MB to the receiver.

gRPC chunking has to be done by the gRPC user. Fragmentation has to be done on the gRPC client side and reassembly has to be done on the gRPC server side. Telemetry is still bound to memory and data can be dropped if the memory size is more than the allowed limit of 12MB for telemetry. In order to support chunking, use the telemetry .proto file that is available at Cisco's GibLab, which has been updated for gRPC chunking, as described in Telemetry Components and Process.

The chunking size is between 64 and 4096 bytes.

Following shows a configuration example through the NX-API CLI:

feature telemetry
!
telemetry
  destination-group 1
    ip address 171.68.197.40 port 50051 protocol gRPC encoding GPB 
    use-chunking size 4096
  destination-group 2
    ip address 10.155.0.15 port 50001 protocol gRPC encoding GPB 
    use-chunking size 64
  sensor-group 1
    path sys/intf depth unbounded
  sensor-group 2
    path sys/intf depth unbounded	
  subscription 1
    dst-grp 1
    snsr-grp 1 sample-interval 10000
  subscription 2
    dst-grp 2
    snsr-grp 2 sample-interval 15000

Following shows a configuration example through the NX-API REST:

{
    "telemetryDestGrpOptChunking": {
        "attributes": {
            "chunkSize": "2048",
            "dn": "sys/tm/dest-1/chunking"
        }
    }
}

The following error message will appear on systems that do not support gRPC chunking, such as the Cisco MDS series switches:

MDS-9706-86(conf-tm-dest)# use-chunking size 200
ERROR: Operation failed: [chunking support not available]

NX-API Sensor Path Limitations

NX-API can collect and stream switch information not yet in the DME using show commands. However, using the NX-API instead of streaming data from the DME has inherent scale limitations as outlined:

  • The switch backend dynamically processes NX-API calls such as show commands,

  • NX-API spawns several processes that can consume up to a maximum of 20% of the CPU.

  • NX-API data translates from the CLI to XML to JSON.

The following is a suggested user flow to help limit excessive NX-API sensor path bandwidth consumption:

  1. Check whether the show command has NX-API support. You can confirm whether NX-API supports the command from the VSH with the pipe option: show <command> | json or show <command> | json pretty.


    Note
    Avoid commands that take the switch more than 30 seconds to return JSON output.

  2. Refine the show command to include any filters or options.

    • Avoid enumerating the same command for individual outputs; i.e., show vlan id 100, show vlan id 101, etc.. Instead, use the CLI range options; i.e., show vlan id 100-110,204, whenever possible to improve performance.

      If only the summary/counter is needed, then avoid dumping a whole show command output to limit the bandwidth and data storage required for data collection.

  3. Configure telemetry with sensor groups that use NX-API as their data sources. Add the show commands as sensor paths

  4. Configure telemetry with a cadence of 5 times the processing time of the respective show command to limit CPI usage.

  5. Receive and process the streamed NX-API output as part of the existing DME collection.

Telemetry VRF Support

Telemetry VRF support allows you to specify a transport VRF. This means that the telemetry data stream can egress via front-panel ports and avoid possible competition between SSH/NGINX control sessions.

You can use the use-vrf vrf-name command to specify the transport VRF.

The following example specifies the transport VRF: 


switch(config)# telemetry
switch(config-telemetry)# destination-profile 
switch(config-tm-dest-profile)# use-vrf test_vrf
The following is an example of use-vrf as a POST payload: 

{
              "telemetryDestProfile": {
                "attributes": {
                  "adminSt": "enabled"
                },
                "children": [
                  {
                    "telemetryDestOptVrf": {
                      "attributes": {
                        "name": "default"
                      }
                    }
                  }
                ]
              }
            }

Configuring Telemetry Using the CLI

Configuring Telemetry Using the NX-OS CLI

The following steps enables streaming telemetry, and configures the source and destination of the data stream. These steps also include optional steps to enable and configure SSL/TLS certificates and GPB encoding.

Before you begin

Your switch must be running Cisco NX-OS Release 9.2(1) or a later release.

SUMMARY STEPS

  1. (Optional) openssl argument
  2. configure terminal
  3. feature telemetry
  4. feature nxapi
  5. nxapi use-vrf management
  6. telemetry
  7. (Optional) certificate certificate_path host_URL
  8. (Optional) Specify a transport VRF and/or enable telemetry compression for gRPC transport.
  9. sensor-group sgrp_id
  10. (Optional) data-source data-source-type
  11. path sensor_path depth 0 [filter-condition filter]
  12. destination-group dgrp_id
  13. (Optional) ip address ip_address port port protocol procedural-protocol encoding encoding-protocol
  14. ip_version address ip_address port portnum
  15. subscription sub_id
  16. snsr-grp sgrp_id sample-interval interval
  17. dst-grp dgrp_id

DETAILED STEPS

  Command or Action Purpose
Step 1

(Optional) openssl argument

Example:

Generate an SSL/TLS certificate using a specific argument, such as the following:

  • To generate a private RSA key: openssl genrsa -cipher -out filename.key cipher-bit-length

    For example:

    switch# openssl genrsa -des3 server.key 2048

  • To write the RSA key: openssl rsa -in filename.key -out filename.key

    For example:

    switch# openssl rsa -in server.key -out server.key

  • To create a certificate that contains the public/private key: openssl req

    -encoding-standard -new -new filename.key -out filename.csr -subj '/CN=localhost'

    For example:

    switch# openssl req -sha256 -new -key server.key -out server.csr 
-subj '/CN=localhost'

  • To create a public key: openssl x509 -req -encoding-standard -days timeframe -in filename.csr -signkey filename.key -out filename.csr

    For example:

    switch# openssl x509 -req -sha256 -days 365 -in server.csr -signkey server.key 
-out server.crt
 (Optional)

Create an SSL/TLS certificate on the server that will receive the data, where private.key file is the private key and the public.crt is the public key.

Step 2

configure terminal

Example:

switch# configure terminal
switch(config)#

Enter the global configuration mode.
Step 3

feature telemetry

Enable the streaming telemetry feature.
Step 4

feature nxapi

Enable nxapi.
Step 5

nxapi use-vrf management

Enable the VRF management to be used for nxapi communication.
Step 6

telemetry

Example:

switch(config)# telemetry
switch(config-telemetry)#

Enter configuration mode for streaming telemetry.
Step 7

(Optional) certificate certificate_path host_URL

Example:

switch(config-telemetry)# certificate /bootflash/server.key localhost
 (Optional)

Use an existing SSL/TLS certificate.
Step 8

(Optional) Specify a transport VRF and/or enable telemetry compression for gRPC transport.

Example:


switch(config-telemetry)# destination-profile
switch(conf-tm-dest-profile)# use-vrf default
switch(conf-tm-dest-profile)# use-compression gzip
switch(conf-tm-dest-profile)# use-retry size 10
switch(conf-tm-dest-profile)# source-interface loopback1
(Optional)

  • Enter the destination-profile command to specify the default destination profile.

  • Enter any of the following commands:

    • use-vrf vrf to specify the destination vrf.

    • use-compression gzip to specify the destination compression method.

    • use-retry size size to specify the send retry details, with a retry buffer size between 10 and 1500 megabytes.

    • source-interface interface-name to stream data from the configured interface to a destination with the source IP address.

Note 

After configuring the use-vrf command, you need to configure a new destination IP address within the new VRF. However, you may re-use the same destination IP address by un-configuring and re-configuring the destination. This ensures that the telemetry data streams to the same destination IP address in the new VRF.

Step 9

sensor-group sgrp_id

Example:

switch(config-telemetry)# sensor-group 100
switch(conf-tm-sensor)#

Create a sensor group with ID srgp_id and enter sensor group configuration mode.

Currently only numeric ID values are supported. The sensor group defines nodes that will be monitored for telemetry reporting.

Step 10

(Optional) data-source data-source-type

Example:

switch(config-telemetry)# data-source NX-API
 (Optional)

Select a data source. Select from either DME or NX-API as the data source.

Note 
DME is the default data source.
Step 11

path sensor_path depth 0 [filter-condition filter]

Example:

  • The following command is applicable for DME, not for NX-API:
    switch(conf-tm-sensor)# path sys/bd/bd-[vlan-100] depth 0 
filter-condition eq(l2BD.operSt, "down")

    Use the syntax below for state-based filtering to trigger only when operSt changes from up to down, with no notifications of when the MO changes. 

    switch(conf-tm-sensor)# path sys/bd/bd-[vlan-100] depth 0 
filter-condition and(updated(l2BD.operSt),eq(l2BD.operSt,"down"))
  • The following command is applicable for NX-API, not for DME:
    switch(conf-tm-sensor)# path "show interface" depth 0

Add a sensor path to the sensor group.

  • The depth setting specifies the retrieval level for the sensor path. Depth settings of 0 - 32 , unbounded are supported.

    Note 

    depth 0 is the default depth.

    NX-API-based sensor paths can only use depth 0 .

    If a path is subscribed for the event collection, the depth only supports 0 and unbounded. Other values would be treated as 0.

  • The optional filter-condition parameter can be specified to create a specific filter for event-based subscriptions.

    For state-based filtering, the filter will return both when a state has changed and when an event has occurred during the specified state. That is, a filter condition for the DN sys/bd/bd-[vlan] of eq(l2Bd.operSt, "down") will trigger when the operSt changes, and when the DN's property changes while the operSt remains down , such as a no shutdown command is issued while the vlan is operationally down .

    Note 

    query-condition parameter — For DME, based on the DN, the query-condition parameter can be specified to fetch MOTL and ephemeral data with the following syntax: query-condition "rsp-foreign-subtree=applied-config"; query-condition "rsp-foreign-subtree=ephemeral".

Step 12

destination-group dgrp_id

Example:

switch(conf-tm-sensor)# destination-group 100
switch(conf-tm-dest)#

Create a destination group and enter destination group configuration mode.

Currently dgrp_id only supports numeric ID values.

Step 13

(Optional) ip address ip_address port port protocol procedural-protocol encoding encoding-protocol

Example:

switch(conf-tm-sensor)# ip address 171.70.55.69 port 50001 protocol gRPC encoding GPB
switch(conf-tm-sensor)# ip address 171.70.55.69 port 50007 protocol HTTP encoding JSON

switch(conf-tm-sensor)# ip address 171.70.55.69 port 50009 protocol UDP encoding JSON
(Optional)

Specify an IPv4 IP address and port to receive encoded telemetry data.

Note 

gRPC is the default transport protocol.

GPB is the default encoding.

Step 14

ip_version address ip_address port portnum

Example:

switch(conf-tm-dest)# ip address 1.2.3.4 port 50003

Create a destination profile for the outgoing data.

When the destination group is linked to a subscription, telemetry data is sent to the IP address and port specified by this profile.

Step 15

subscription sub_id

Example:

switch(conf-tm-dest)# subscription 100
switch(conf-tm-sub)#

Create a subscription node with ID and enter the subscription configuration mode.

Currently sub_id only supports numeric ID values.

Note 
When subscribing to to a DN, check whether the DN is supported by DME using REST to ensure that events will stream.
Step 16

snsr-grp sgrp_id sample-interval interval

Example:

switch(conf-tm-sub)# snsr-grp 100 sample-interval 15000

Link the sensor group with ID sgrp_id to this subscription and set the data sampling interval in milliseconds.

An interval value of 0 creates an event-based subscription, in which telemetry data is sent only upon changes under the specified MO. An interval value greater than 0 creates a frequency-based subscription, in which telemetry data is sent periodically at the specified interval. For example, an interval value of 15000 results in the sending of telemetry data every 15 seconds.

Step 17

dst-grp dgrp_id

Example:

switch(conf-tm-sub)# dst-grp 100

Link the destination group with ID dgrp_id to this subscription.

Configuration Examples for Telemetry Using the CLI

This example creates a subscription that streams data for the sys/bgp root MO every 5 seconds to the destination IP 1.2.3.4 port 50003. 


switch(config)# telemetry
switch(config-telemetry)# sensor-group 100
switch(conf-tm-sensor)# path sys/bgp depth 0
switch(conf-tm-sensor)# destination-group 100
switch(conf-tm-dest)# ip address 1.2.3.4 port 50003
switch(conf-tm-dest)# subscription 100
switch(conf-tm-sub)# snsr-grp 100 sample-interval 5000
switch(conf-tm-sub)# dst-grp 100

This example creates a subscription that streams data for sys/intf every 5 seconds to destination IP 1.2.3.4 port 50003, and encrypts the stream using GPB encoding verified using the test.pem. 

switch(config)# telemetry
switch(config-telemetry)# certificate /bootflash/test.pem foo.test.google.fr
switch(conf-tm-telemetry)# destination-group 100
switch(conf-tm-dest)# ip address 1.2.3.4 port 50003 protocol gRPC encoding GPB
switch(config-dest)# sensor-group 100
switch(conf-tm-sensor)# path sys/bgp depth 0
switch(conf-tm-sensor)# subscription 100
switch(conf-tm-sub)# snsr-grp 100 sample-interval 5000
switch(conf-tm-sub)# dst-grp 100

This example creates a subscription that streams data for sys/cdp every 15 seconds to destination IP 1.2.3.4 port 50004. 


switch(config)# telemetry
switch(config-telemetry)# sensor-group 100
switch(conf-tm-sensor)# path sys/cdp depth 0
switch(conf-tm-sensor)# destination-group 100
switch(conf-tm-dest)# ip address 1.2.3.4 port 50004
switch(conf-tm-dest)# subscription 100
switch(conf-tm-sub)# snsr-grp 100 sample-interval 15000
switch(conf-tm-sub)# dst-grp 100

This example creates a cadence-based collection of show command data every 750 seconds. 


switch(config)# telemetry
switch(config-telemetry)# destination-group 1
switch(conf-tm-dest)# ip address 172.27.247.72 port 60001 protocol gRPC encoding GPB 
switch(conf-tm-dest)# sensor-group 1
switch(conf-tm-sensor# data-source NX-API
switch(conf-tm-sensor)# path "show system resources" depth 0
switch(conf-tm-sensor)# path "show version" depth 0 
switch(conf-tm-sensor)# path "show environment power" depth 0 
switch(conf-tm-sensor)# path "show environment fan" depth 0 
switch(conf-tm-sensor)# path "show environment temperature" depth 0 
switch(conf-tm-sensor)# path "show process cpu" depth 0 
switch(conf-tm-sensor)# path "show nve peers" depth 0 
switch(conf-tm-sensor)# path "show nve vni" depth 0 
switch(conf-tm-sensor)# path "show nve vni 4002 counters" depth 0 
switch(conf-tm-sensor)# path "show int nve 1 counters" depth 0 
switch(conf-tm-sensor)# path "show policy-map vlan" depth 0 
switch(conf-tm-sensor)# path "show ip access-list test" depth 0 
switch(conf-tm-sensor)# path "show system internal access-list resource utilization" depth 0 
switch(conf-tm-sensor)# subscription 1
switch(conf-tm-sub)# dst-grp 1
switch(conf-tm-dest)# snsr-grp 1 sample-interval 750000

This example creates an event-based subscription for sys/fm. Data is streamed to the destination only if there is a change under the sys/fm MO. 


switch(config)# telemetry
switch(config-telemetry)# sensor-group 100
switch(conf-tm-sensor)# path sys/fm depth 0
switch(conf-tm-sensor)# destination-group 100
switch(conf-tm-dest)# ip address 1.2.3.4 port 50005
switch(conf-tm-dest)# subscription 100
switch(conf-tm-sub)# snsr-grp 100 sample-interval 0
switch(conf-tm-sub)# dst-grp 100

During operation, you can change a sensor group from frequency-based to event-based, and change event-based to frequency-based by changing the sample-interval. This example changes the sensor-group from the previous example to frequency-based. After the following commands, the telemetry application will begin streaming the sys/fm data to the destination every 7 seconds. 


switch(config)# telemetry
switch(config-telemetry)# subscription 100
switch(conf-tm-sub)# snsr-grp 100 sample-interval 7000

Multiple sensor groups and destinations can be linked to a single subscription. The subscription in this example streams the data for Ethernet port 1/1 to four different destinations every 10 seconds. 


switch(config)# telemetry
switch(config-telemetry)# sensor-group 100
switch(conf-tm-sensor)# path sys/intf/phys-[eth1/1] depth 0
switch(conf-tm-sensor)# destination-group 100
switch(conf-tm-dest)# ip address 1.2.3.4 port 50004
switch(conf-tm-dest)# ip address 1.2.3.4 port 50005
switch(conf-tm-sensor)# destination-group 200
switch(conf-tm-dest)# ip address 5.6.7.8 port 50001 protocol HTTP encoding JSON
switch(conf-tm-dest)# ip address 1.4.8.2 port 60003
switch(conf-tm-dest)# subscription 100
switch(conf-tm-sub)# snsr-grp 100 sample-interval 10000
switch(conf-tm-sub)# dst-grp 100
switch(conf-tm-sub)# dst-grp 200

A sensor group can contain multiple paths, a destination group can contain multiple destination profiles, and a subscription can be linked to multiple sensor groups and destination groups, as shown in this example. 


switch(config)# telemetry
switch(config-telemetry)# sensor-group 100
switch(conf-tm-sensor)# path sys/intf/phys-[eth1/1] depth 0
switch(conf-tm-sensor)# path sys/epId-1 depth 0
switch(conf-tm-sensor)# path sys/bgp/inst/dom-default depth 0

switch(config-telemetry)# sensor-group 200
switch(conf-tm-sensor)# path sys/cdp depth 0
switch(conf-tm-sensor)# path sys/ipv4 depth 0

switch(config-telemetry)# sensor-group 300
switch(conf-tm-sensor)# path sys/fm depth 0
switch(conf-tm-sensor)# path sys/bgp depth 0

switch(conf-tm-sensor)# destination-group 100
switch(conf-tm-dest)# ip address 1.2.3.4 port 50004
switch(conf-tm-dest)# ip address 4.3.2.5 port 50005

switch(conf-tm-dest)# destination-group 200
switch(conf-tm-dest)# ip address 5.6.7.8 port 50001

switch(conf-tm-dest)# destination-group 300
switch(conf-tm-dest)# ip address 1.2.3.4 port 60003

switch(conf-tm-dest)# subscription 600
switch(conf-tm-sub)# snsr-grp 100 sample-interval 7000
switch(conf-tm-sub)# snsr-grp 200 sample-interval 20000
switch(conf-tm-sub)# dst-grp 100
switch(conf-tm-sub)# dst-grp 200

switch(conf-tm-dest)# subscription 900
switch(conf-tm-sub)# snsr-grp 200 sample-interval 7000
switch(conf-tm-sub)# snsr-grp 300 sample-interval 0
switch(conf-tm-sub)# dst-grp 100
switch(conf-tm-sub)# dst-grp 300

You can verify the telemetry configuration using the show running-config telemetry command, as shown in this example. 


switch(config)# telemetry 
switch(config-telemetry)# destination-group 100
switch(conf-tm-dest)# ip address 1.2.3.4 port 50003
switch(conf-tm-dest)# ip address 1.2.3.4 port 50004
switch(conf-tm-dest)# end
switch# show run telemetry 

!Command: show running-config telemetry
!Time: Thu Oct 13 21:10:12 2016

version 7.0(3)I5(1)
feature telemetry

telemetry
destination-group 100
ip address 1.2.3.4 port 50003 protocol gRPC encoding GPB 
ip address 1.2.3.4 port 50004 protocol gRPC encoding GPB

You can specify transport VRF and telemetry data compression for gRPC using the use-vrf and use-compression gzip commands, as shown in this example. 


switch(config)# telemetry
switch(config-telemetry)# destination-profile
switch(conf-tm-dest-profile)# use-vrf default
switch(conf-tm-dest-profile)# use-compression gzip
switch(conf-tm-dest-profile)# sensor-group 1
switch(conf-tm-sensor)# path sys/bgp depth unbounded
switch(conf-tm-sensor)# destination-group 1
switch(conf-tm-dest)# ip address 1.2.3.4 port 50004
switch(conf-tm-dest)# subscription 1
switch(conf-tm-sub)# dst-grp 1
switch(conf-tm-sub)# snsr-grp 1 sample-interval 10000

Displaying Telemetry Configuration and Statistics

Use the following NX-OS CLI show commands to display telemetry configuration, statistics, errors, and session information.

show telemetry control database

This command displays the internal databases that reflect the configuration of telemetry.


switch# show telemetry control database ?
  <CR>                
  >                   Redirect it to a file
  >>                  Redirect it to a file in append mode
  destination-groups  Show destination-groups
  destinations        Show destinations
  sensor-groups       Show sensor-groups
  sensor-paths        Show sensor-paths
  subscriptions       Show subscriptions
  |                   Pipe command output to filter

switch# show telemetry control database 

Subscription Database size = 1

--------------------------------------------------------------------------------
Subscription ID      Data Collector Type 
--------------------------------------------------------------------------------
100                  DME NX-API                

Sensor Group Database size = 1

--------------------------------------------------------------------------------
Sensor Group ID  Sensor Group type  Sampling interval(ms)  Linked subscriptions 
--------------------------------------------------------------------------------
100              Timer              10000(Running)         1                    

Sensor Path Database size = 1

--------------------------------------------------------------------------------
Subscribed Query Filter  Linked Groups  Sec Groups  Retrieve level  Sensor Path 
--------------------------------------------------------------------------------
No                       1              0           Full            sys/fm      

Destination group Database size = 2

--------------------------------------------------------------------------------
Destination Group ID  Refcount  
--------------------------------------------------------------------------------
100                   1         

Destination Database size = 2

--------------------------------------------------------------------------------
Dst IP Addr     Dst Port   Encoding   Transport  Count     
--------------------------------------------------------------------------------
192.168.20.111       12345      JSON       HTTP       1
192.168.20.123	50001      GPB        gRPC       1

show telemetry control stats

This command displays the statistic regarding the internal databases regarding configuration of telemetry.


switch# show telemetry control stats 
show telemetry control stats entered

--------------------------------------------------------------------------------
Error Description                                            Error Count 
--------------------------------------------------------------------------------
Chunk allocation failures                                    0
Sensor path Database chunk creation failures                 0
Sensor Group Database chunk creation failures                0
Destination Database chunk creation failures                 0
Destination Group Database chunk creation failures           0
Subscription Database chunk creation failures                0
Sensor path Database creation failures                       0
Sensor Group Database creation failures                      0
Destination Database creation failures                       0
Destination Group Database creation failures                 0
Subscription Database creation failures                      0
Sensor path Database insert failures                         0
Sensor Group Database insert failures                        0
Destination Database insert failures                         0
Destination Group Database insert failures                   0
Subscription insert to Subscription Database failures        0
Sensor path Database delete failures                         0
Sensor Group Database delete failures                        0
Destination Database delete failures                         0
Destination Group Database delete failures                   0
Delete Subscription from Subscription Database failures      0
Sensor path delete in use                                    0
Sensor Group delete in use                                   0
Destination delete in use                                    0
Destination Group delete in use                              0
Delete destination(in use) failure count                     0
Failed to get encode callback                                0
Sensor path Sensor Group list creation failures              0
Sensor path prop list creation failures                      0
Sensor path sec Sensor path list creation failures           0
Sensor path sec Sensor Group list creation failures          0
Sensor Group Sensor path list creation failures              0
Sensor Group Sensor subs list creation failures              0
Destination Group subs list creation failures                0
Destination Group Destinations list creation failures        0
Destination Destination Groups list creation failures        0
Subscription Sensor Group list creation failures             0
Subscription Destination Groups list creation failures       0
Sensor Group Sensor path list delete failures                0
Sensor Group Subscriptions list delete failures              0
Destination Group Subscriptions list delete failures         0
Destination Group Destinations list delete failures          0
Subscription Sensor Groups list delete failures              0
Subscription Destination Groups list delete failures         0
Destination Destination Groups list delete failures          0
Failed to delete Destination from Destination Group          0
Failed to delete Destination Group from Subscription         0
Failed to delete Sensor Group from Subscription              0
Failed to delete Sensor path from Sensor Group               0
Failed to get encode callback                                0
Failed to get transport callback                             0
switch#  Destination Database size = 1

--------------------------------------------------------------------------------
Dst IP Addr     Dst Port   Encoding   Transport  Count     
--------------------------------------------------------------------------------
192.168.20.123	50001      GPB        gRPC       1

show telemetry data collector brief

This command displays the brief statistic regarding the data collection.


switch# show telemetry data collector brief 

----------------------------------------------------------------------
Collector Type       Successful Collections     Failed Collections        
----------------------------------------------------------------------
DME                   143                        0

show telemetry data collector details

This command displays details statistic regarding the data collection which includes breakdown of all sensor paths.


switch# show telemetry data collector details 

--------------------------------------------------------------------------------
Succ Collections      Failed Collections     Sensor Path
--------------------------------------------------------------------------------
150                   0                      sys/fm

show telemetry event collector errors

This command displays the errors statistic regarding the event collection.


switch# show telemetry event collector errors 

--------------------------------------------------------------------------------
Error Description                                  Error Count 
--------------------------------------------------------------------------------
APIC-Cookie Generation Failures                    - 0
Authentication Failures                            - 0
Authentication Refresh Failures                    - 0
Authentication Refresh Timer Start Failures        - 0
Connection Timer Start Failures                    - 0
Connection Attempts                                - 3
Dme Event Subscription Init Failures               - 0
Event Data Enqueue Failures                        - 0
Event Subscription Failures                        - 0
Event Subscription Refresh Failures                - 0
Pending Subscription List Create Failures          - 0
Subscription Hash Table Create Failures            - 0
Subscription Hash Table Destroy Failures           - 0
Subscription Hash Table Insert Failures            - 0
Subscription Hash Table Remove Failures            - 0
Subscription Refresh Timer Start Failures          - 0
Websocket Connect Failures                         - 0

show telemetry event collector stats

This command displays the statistic regarding the event collection which includes breakdown of all sensor paths.


switch# show telemetry event collector stats 

--------------------------------------------------------------------------------
Collection Count  Latest Collection Time    Sensor Path
--------------------------------------------------------------------------------

show telemetry control pipeline stats

This command displays the statistic for the telemetry pipeline.


switch# show telemetry pipeline stats 
Main Statistics:
    Timers:
        Errors:
            Start Fail        =     0

    Data Collector:
        Errors:
            Node Create Fail  =     0

    Event Collector:
        Errors:
            Node Create Fail  =     0    Node Add Fail     =     0
            Invalid Data      =     0

Queue Statistics:
    Request Queue:
        High Priority Queue:
            Info:
                Actual Size       =    50    Current Size      =     0
                Max Size          =     0    Full Count        =     0

            Errors:
                Enqueue Error     =     0    Dequeue Error     =     0

        Low Priority Queue:
            Info:
                Actual Size       =    50    Current Size      =     0
                Max Size          =     0    Full Count        =     0

            Errors:
                Enqueue Error     =     0    Dequeue Error     =     0

    Data Queue:
        High Priority Queue:
            Info:
                Actual Size       =    50    Current Size      =     0
                Max Size          =     0    Full Count        =     0

            Errors:
                Enqueue Error     =     0    Dequeue Error     =     0

        Low Priority Queue:
            Info:
                Actual Size       =    50    Current Size      =     0
                Max Size          =     0    Full Count        =     0

            Errors:
                Enqueue Error     =     0    Dequeue Error     =     0

show telemetry transport

This command displays all configured transport sessions.


switch# show telemetry transport 

Session Id      IP Address      Port       Encoding   Transport  Status    
-----------------------------------------------------------------------------------
0               192.168.20.123   50001      GPB        gRPC       Connected

show telemetry transport <session-id>

This command displays detailed session information for a specific transport session.


switch# show telemetry transport 0 

Session Id:          0                   
IP Address:Port      192.168.20.123:50001 
Encoding:            GPB                 
Transport:           gRPC                
Status:              Disconnected        
Last Connected:      Fri Sep 02 11:45:57.505 UTC
Tx Error Count:      224                 
Last Tx Error:       Fri Sep 02 12:23:49.555 UTC

switch# show telemetry transport 1

Session Id:          1                   
IP Address:Port      10.30.218.56:51235  
Encoding:            JSON                
Transport:           HTTP                
Status:              Disconnected        
Last Connected:      Never               
Last Disconnected:   Never               
Tx Error Count:      3                   
Last Tx Error:       Wed Apr 19 15:56:51.617 PDT

show telemetry transport <session-id> stats

This command displays details of a specific transport session.


switch# show telemetry transport 0 stats 

Session Id:          0                   
IP Address:Port      192.168.20.123:50001 
Encoding:            GPB                 
Transport:           GRPC                
Status:              Connected           
Last Connected:      Mon May 01 11:29:46.912 PST
Last Disconnected:   Never               
Tx Error Count:      0                   
Last Tx Error:       None

show telemetry transport <session-id> errors

This command displays detailed error statistics for a specific transport session.


switch# show telemetry transport 0 errors 

Session Id:                    0                   
Connection Stats                                   
   Connection Count            1                   
   Last Connected:             Mon May 01 11:29:46.912 PST
   Disconnect Count            0                   
   Last Disconnected:          Never               
Transmission Stats                                 
   Transmit Count:             1225                
   Last TX time:               Tue May 02 11:40:03.531 PST
   Min Tx Time:                7                   ms
   Max Tx Time:                1760                ms
   Avg Tx Time:                500                 ms

Displaying Telemetry Log and Trace Information

Use the following NX-OS CLI commands to display the log and trace information.

show tech-support telemetry

This NX-OS CLI command collects the telemetry log contents from the tech-support log. In this example, the command output is redirected into a file in bootflash. 


switch# show tech-support telemetry > bootflash:tmst.log

show system internal telemetry trace

The show system internal telemetry trace [tm-events | tm-errors |tm-logs | all] command displays system internal telemetry trace information. 


switch# show system internal telemetry trace all
Telemetry All Traces:
Telemetry Error Traces:
[07/26/17 15:22:29.156 UTC 1 28577] [3960399872][tm_cfg_api.c:367] Not able to destroy dest profile list for config node rc:-1610612714 reason:Invalid argument
[07/26/17 15:22:44.972 UTC 2 28577] [3960399872][tm_stream.c:248] No subscriptions for destination group 1
[07/26/17 15:22:49.463 UTC 3 28577] [3960399872][tm_stream.c:576] TM_STREAM: Subscriptoin 1 does not have any sensor groups

3 entries printed
Telemetry Event Traces:
[07/26/17 15:19:40.610 UTC 1 28577] [3960399872][tm_debug.c:41] Telemetry xostrace buffers initialized successfully!
[07/26/17 15:19:40.610 UTC 2 28577] [3960399872][tm.c:744] Telemetry statistics created successfully!
[07/26/17 15:19:40.610 UTC 3 28577] [3960399872][tm_init_n9k.c:97] Platform intf: grpc_traces:compression,channel
switch# 

switch# show system internal telemetry trace tm-logs
Telemetry Log Traces:
0 entries printed
switch#
switch# show system internal telemetry trace tm-events
Telemetry Event Traces:
[07/26/17 15:19:40.610 UTC 1 28577] [3960399872][tm_debug.c:41] Telemetry xostrace buffers initialized successfully!
[07/26/17 15:19:40.610 UTC 2 28577] [3960399872][tm.c:744] Telemetry statistics created successfully!
[07/26/17 15:19:40.610 UTC 3 28577] [3960399872][tm_init_n9k.c:97] Platform intf: grpc_traces:compression,channel
[07/26/17 15:19:40.610 UTC 4 28577] [3960399872][tm_init_n9k.c:207] Adding telemetry to cgroup
[07/26/17 15:19:40.670 UTC 5 28577] [3960399872][tm_init_n9k.c:215] Added telemetry to cgroup successfully!

switch# show system internal telemetry trace tm-errors
Telemetry Error Traces:
0 entries printed
switch#

Configuring Telemetry Using the NX-API

Configuring Telemetry Using the NX-API

In the object model of the switch DME, the configuration of the telemetry feature is defined in a hierarchical structure of objects as shown in Telemetry Model in the DME. Following are the main objects to be configured:

  • fmEntity — Contains the NX-API and Telemetry feature states.

    • fmNxapi — Contains the NX-API state.

    • fmTelemetry — Contains the Telemetry feature state.

  • telemetryEntity — Contains the telemetry feature configuration.

    • telemetrySensorGroup — Contains the definitions of one or more sensor paths or nodes to be monitored for telemetry. The telemetry entity can contain one or more sensor groups.

      • telemetryRtSensorGroupRel — Associates the sensor group with a telemetry subscription.

      • telemetrySensorPath — A path to be monitored. The sensor group can contain multiple objects of this type.

    • telemetryDestGroup — Contains the definitions of one or more destinations to receive telemetry data. The telemetry entity can contain one or more destination groups.

      • telemetryRtDestGroupRel — Associates the destination group with a telemetry subscription.

      • telemetryDest — A destination address. The destination group can contain multiple objects of this type.

    • telemetrySubscription — Specifies how and when the telemetry data from one or more sensor groups is sent to one or more destination groups.

      • telemetryRsDestGroupRel — Associates the telemetry subscription with a destination group.

      • telemetryRsSensorGroupRel — Associates the telemetry subscription with a sensor group.

    • telemetryCertificate — Associates the telemetry subscription with a certificate and hostname.

To configure the telemetry feature using the NX-API, you must construct a JSON representation of the telemetry object structure and push it to the DME with an HTTP or HTTPS POST operation.


Note
For detailed instructions on using the NX-API, see the Cisco Nexus 3000 and 9000 Series NX-API REST SDK User Guide and API Reference.

Before you begin

Your switch must be configured to run the NX-API from the CLI:

switch(config)# feature nxapi


nxapi use-vrf vrf_name
nxapi http port port_number

SUMMARY STEPS

  1. Enable the telemetry feature.
  2. Create the root level of the JSON payload to describe the telemetry configuration.
  3. Create a sensor group to contain the defined sensor paths.
  4. (Optional) Add an SSL/TLS certificate and a host.
  5. Define a telemetry destination group.
  6. Define a telemetry destination profile.
  7. Define one or more telemetry destinations, consisting of an IP address and port number to which telemetry data will be sent.
  8. Enable gRPC chunking and set the chunking size, between 64 and 4096 bytes.
  9. Create a telemetry subscription to configure the telemetry behavior.
  10. Add the sensor group object as a child object to the telemetrySubscription element under the root element (telemetryEntity ).
  11. Create a relation object as a child object of the subscription to associate the subscription to the telemetry sensor group and to specify the data sampling behavior.
  12. Define one or more sensor paths or nodes to be monitored for telemetry.
  13. Add sensor paths as child objects to the sensor group object (telemetrySensorGroup ).
  14. Add destinations as child objects to the destination group object (telemetryDestGroup ).
  15. Add the destination group object as a child object to the root element (telemetryEntity ).
  16. Create a relation object as a child object of the telemetry sensor group to associate the sensor group to the subscription.
  17. Create a relation object as a child object of the telemetry destination group to associate the destination group to the subscription.
  18. Create a relation object as a child object of the subscription to associate the subscription to the telemetry destination group.
  19. Send the resulting JSON structure as an HTTP/HTTPS POST payload to the NX-API endpoint for telemetry configuration.

DETAILED STEPS

  Command or Action Purpose
Step 1

Enable the telemetry feature.

Example:


{
  "fmEntity" : {
    "children" : [{ 
      "fmTelemetry" : {
        "attributes" : {
          "adminSt" : "enabled"
        }
      }
    }
    ]
  }
}

The root element is fmTelemetry and the base path for this element is sys/fm. Configure the adminSt attribute as enabled.

Step 2

Create the root level of the JSON payload to describe the telemetry configuration.

Example:


{
    "telemetryEntity": {
        "attributes": {
            "dn": "sys/tm"
        },
    }
}

The root element is telemetryEntity and the base path for this element is sys/tm. Configure the dn attribute as sys/tm.

Step 3

Create a sensor group to contain the defined sensor paths.

Example:


"telemetrySensorGroup": {
    "attributes": {
        "id": "10",
        "rn": "sensor-10"
        "dataSrc": "NX-API"
    },  "children": [{
    }]
}

A telemetry sensor group is defined in an object of class telemetrySensorGroup . Configure the following attributes of the object:

  • id — An identifier for the sensor group. Currently only numeric ID values are supported.

  • rn — The relative name of the sensor group object in the format: sensor-id .

  • dataSrc — Selects the data source from DEFAULT , DME , or NX-API .

Children of the sensor group object will include sensor paths and one or more relation objects (telemetryRtSensorGroupRel ) to associate the sensor group with a telemetry subscription.

Step 4

(Optional) Add an SSL/TLS certificate and a host.

Example:

{
    "telemetryCertificate": {
        "attributes": {
            "filename": "root.pem"
             "hostname": "c.com"
         }
    }
}
 (Optional)

The telemetryCertificate defines the location of the SSL/TLS certificate with the telemetry subscription/destination.

Step 5

Define a telemetry destination group.

Example:

{
      "telemetryDestGroup": {
        "attributes": {
          "id": "20"
        }
      }
}

A telemetry destination group is defined in telemetryEntity . Configure the id attribute.

Step 6

Define a telemetry destination profile.

Example:


{
   "telemetryDestProfile": {
      "attributes": {
         "adminSt": "enabled"
      },
      "children": [
         {
            "telemetryDestOptSourceInterface": {
               "attributes": {
                  "name": "lo0"
               }
            }
         }
      ]
   }
}

A telemetry destination profile is defined in telemetryDestProfile .

  • Configure the adminSt attribute as enabled.

  • Under telemetryDestOptSourceInterface , configure the name attribute with an interface name to stream data from the configured interface to a destination with the source IP address.

Step 7

Define one or more telemetry destinations, consisting of an IP address and port number to which telemetry data will be sent.

Example:


{
    "telemetryDest": {
        "attributes": {
             "addr": "1.2.3.4",
             "enc": "GPB",
             "port": "50001",
             "proto": "gRPC",
             "rn": "addr-[1.2.3.4]-port-50001"
        }
    }
}

A telemetry destination is defined in an object of class telemetryDest . Configure the following attributes of the object:

  • addr — The IP address of the destination.

  • port — The port number of the destination.

  • rn — The relative name of the destination object in the format: path-[path] .

  • enc — The encoding type of the telemetry data to be sent. NX-OS supports:

    • Google protocol buffers (GPB) for gRPC.

    • JSON for C.

    • GPB or JSON for UDP and secure UDP (DTLS).

  • proto — The transport protocol type of the telemetry data to be sent. NX-OS supports:

    • gRPC

    • HTTP

    • VUDP and secure UDP (DTLS)
Step 8

Enable gRPC chunking and set the chunking size, between 64 and 4096 bytes.

Example:


{
    "telemetryDestGrpOptChunking": {
        "attributes": {
            "chunkSize": "2048",
            "dn": "sys/tm/dest-1/chunking"
        }
    }
}

See Support for gRPC Chunking for more information.

Step 9

Create a telemetry subscription to configure the telemetry behavior.

Example:


"telemetrySubscription": {
    "attributes": {
        "id": "30",
        "rn": "subs-30"
    },  "children": [{
    }]
}

A telemetry subscription is defined in an object of class telemetrySubscription . Configure the following attributes of the object:

  • id — An identifier for the subscription. Currently only numeric ID values are supported.

  • rn — The relative name of the subscription object in the format: subs-id .

Children of the subscription object will include relation objects for sensor groups (telemetryRsSensorGroupRel ) and destination groups (telemetryRsDestGroupRel ).

Step 10

Add the sensor group object as a child object to the telemetrySubscription element under the root element (telemetryEntity ).

Example:

{
      "telemetrySubscription": {
        "attributes": {
          "id": "30"
        }
        "children": [{
          "telemetryRsSensorGroupRel": {
            "attributes": {
              "sampleIntvl": "5000",
              "tDn": "sys/tm/sensor-10"
            }
          }
        }
        ]
      }
    }
Step 11

Create a relation object as a child object of the subscription to associate the subscription to the telemetry sensor group and to specify the data sampling behavior.

Example:


"telemetryRsSensorGroupRel": {
    "attributes": {
        "rType": "mo",
        "rn": "rssensorGroupRel-[sys/tm/sensor-10]",
        "sampleIntvl": "5000",
        "tCl": "telemetrySensorGroup",
        "tDn": "sys/tm/sensor-10",
        "tType": "mo"
    }
 }

The relation object is of class telemetryRsSensorGroupRel and is a child object of telemetrySubscription . Configure the following attributes of the relation object:

  • rn — The relative name of the relation object in the format: rssensorGroupRel-[sys/tm/sensor-group-id] .

  • sampleIntvl — The data sampling period in milliseconds. An interval value of 0 creates an event-based subscription, in which telemetry data is sent only upon changes under the specified MO. An interval value greater than 0 creates a frequency-based subscription, in which telemetry data is sent periodically at the specified interval. For example, an interval value of 15000 results in the sending of telemetry data every 15 seconds.

  • tCl — The class of the target (sensor group) object, which is telemetrySensorGroup .

  • tDn — The distinguished name of the target (sensor group) object, which is sys/tm/sensor-group-id .

  • rType — The relation type, which is mo for managed object.

  • tType — The target type, which is mo for managed object.

Step 12

Define one or more sensor paths or nodes to be monitored for telemetry.

Example:

Single sensor path

{
    "telemetrySensorPath": {
        "attributes": {
            "path": "sys/cdp",
            "rn": "path-[sys/cdp]",
            "excludeFilter": "",
            "filterCondition": "",
            "path": "sys/fm/bgp",
            "secondaryGroup": "0",
            "secondaryPath": "",
            "depth": "0"
        }
    }
}

Example:

Single sensor path for NX-API

{
    "telemetrySensorPath": {
        "attributes": {
            "path": "show interface",
            "path": "show bgp",
            "rn": "path-[sys/cdp]",
            "excludeFilter": "",
            "filterCondition": "",
            "path": "sys/fm/bgp",
            "secondaryGroup": "0",
            "secondaryPath": "",
            "depth": "0"
        }
    }
}

Example:

Multiple sensor paths

{
    "telemetrySensorPath": {
        "attributes": {
            "path": "sys/cdp",
            "rn": "path-[sys/cdp]",
            "excludeFilter": "",
            "filterCondition": "",
            "path": "sys/fm/bgp",
            "secondaryGroup": "0",
            "secondaryPath": "",
            "depth": "0"
        }
    }
},
{
     "telemetrySensorPath": {
         "attributes": {
            "excludeFilter": "",
            "filterCondition": "",
            "path": "sys/fm/dhcp",
            "secondaryGroup": "0",
            "secondaryPath": "",
            "depth": "0"
        }
    }
}

Example:

Single sensor path filtering for BGP disable events:

{
    "telemetrySensorPath": {
        "attributes": {
            "path": "sys/cdp",
            "rn": "path-[sys/cdp]",
            "excludeFilter": "",
            "filterCondition": "eq(fmBgp.operSt.\"disabled\")",
            "path": "sys/fm/bgp",
            "secondaryGroup": "0",
            "secondaryPath": "",
            "depth": "0"
        }
    }
}

A sensor path is defined in an object of class telemetrySensorPath . Configure the following attributes of the object:

Step 13

Add sensor paths as child objects to the sensor group object (telemetrySensorGroup ).

Step 14

Add destinations as child objects to the destination group object (telemetryDestGroup ).

Step 15

Add the destination group object as a child object to the root element (telemetryEntity ).

Step 16

Create a relation object as a child object of the telemetry sensor group to associate the sensor group to the subscription.

Example:


"telemetryRtSensorGroupRel": {
    "attributes": {
        "rn": "rtsensorGroupRel-[sys/tm/subs-30]",
        "tCl": "telemetrySubscription",
        "tDn": "sys/tm/subs-30"
    }
}

The relation object is of class telemetryRtSensorGroupRel and is a child object of telemetrySensorGroup . Configure the following attributes of the relation object:

  • rn — The relative name of the relation object in the format: rtsensorGroupRel-[sys/tm/subscription-id] .

  • tCl — The target class of the subscription object, which is telemetrySubscription .

  • tDn — The target distinguished name of the subscription object, which is sys/tm/subscription-id .

Step 17

Create a relation object as a child object of the telemetry destination group to associate the destination group to the subscription.

Example:


"telemetryRtDestGroupRel": {
    "attributes": {
        "rn": "rtdestGroupRel-[sys/tm/subs-30]",
        "tCl": "telemetrySubscription",
        "tDn": "sys/tm/subs-30"
    }
}

The relation object is of class telemetryRtDestGroupRel and is a child object of telemetryDestGroup . Configure the following attributes of the relation object:

  • rn — The relative name of the relation object in the format: rtdestGroupRel-[sys/tm/subscription-id] .

  • tCl — The target class of the subscription object, which is telemetrySubscription .

  • tDn — The target distinguished name of the subscription object, which is sys/tm/subscription-id .

Step 18

Create a relation object as a child object of the subscription to associate the subscription to the telemetry destination group.

Example:


"telemetryRsDestGroupRel": {
    "attributes": {
        "rType": "mo",
        "rn": "rsdestGroupRel-[sys/tm/dest-20]",
        "tCl": "telemetryDestGroup",
        "tDn": "sys/tm/dest-20",
        "tType": "mo"
    }
}

The relation object is of class telemetryRsDestGroupRel and is a child object of telemetrySubscription . Configure the following attributes of the relation object:

  • rn — The relative name of the relation object in the format: rsdestGroupRel-[sys/tm/destination-group-id] .

  • tCl — The class of the target (destination group) object, which is telemetryDestGroup .

  • tDn — The distinguished name of the target (destination group) object, which is sys/tm/destination-group-id .

  • rType — The relation type, which is mo for managed object.

  • tType — The target type, which is mo for managed object.

Step 19

Send the resulting JSON structure as an HTTP/HTTPS POST payload to the NX-API endpoint for telemetry configuration.

The base path for the telemetry entity is sys/tm and the NX-API endpoint is: 

{{URL}}/api/node/mo/sys/tm.json

Example

The following is an example of all the previous steps collected into one POST payload (note that some attributes may not match):
{
  "telemetryEntity": {
    "children": [{
      "telemetrySensorGroup": {
        "attributes": {
          "id": "10"
        }
        "children": [{
          "telemetrySensorPath": {
            "attributes": {
              "excludeFilter": "",
              "filterCondition": "",
              "path": "sys/fm/bgp",
              "secondaryGroup": "0",
              "secondaryPath": "",
              "depth": "0"
            }
          }
        }
        ]
      }
    },
    {
      "telemetryDestGroup": {
        "attributes": {
          "id": "20"
        }
        "children": [{
          "telemetryDest": {
            "attributes": {
              "addr": "10.30.217.80",
              "port": "50051",
              "enc": "GPB",
              "proto": "gRPC"
            }
          }
        }
        ]
      }
    },
    {
      "telemetrySubscription": {
        "attributes": {
          "id": "30"
        }
        "children": [{
          "telemetryRsSensorGroupRel": {
            "attributes": {
              "sampleIntvl": "5000",
              "tDn": "sys/tm/sensor-10"
            }
          }
        },
        {
          "telemetryRsDestGroupRel": {
            "attributes": {
              "tDn": "sys/tm/dest-20"
            }
          }
        }
        ]
      }
    }
    ]
  }
}

Configuration Example for Telemetry Using the NX-API

Streaming Paths to a Destination

This example creates a subscription that streams paths sys/cdp and sys/ipv4 to a destination 1.2.3.4 port 50001 every five seconds. 


POST https://192.168.20.123/api/node/mo/sys/tm.json

Payload:
{
    "telemetryEntity": {
        "attributes": {
            "dn": "sys/tm"
        },
        "children": [{
            "telemetrySensorGroup": {
                "attributes": {
                    "id": "10",
                    "rn": "sensor-10"
                },  "children": [{
                    "telemetryRtSensorGroupRel": {
                        "attributes": {
                            "rn": "rtsensorGroupRel-[sys/tm/subs-30]",
                            "tCl": "telemetrySubscription",
                            "tDn": "sys/tm/subs-30"
                        }
                    }
                }, {
                    "telemetrySensorPath": {
                        "attributes": {
                            "path": "sys/cdp",
                            "rn": "path-[sys/cdp]",
                            "excludeFilter": "",
                            "filterCondition": "",
                            "secondaryGroup": "0",
                            "secondaryPath": "",
                            "depth": "0"
                        }
                    }
                }, {
                    "telemetrySensorPath": {
                        "attributes": {
                            "path": "sys/ipv4",
                            "rn": "path-[sys/ipv4]",
                            "excludeFilter": "",
                            "filterCondition": "",
                            "secondaryGroup": "0",
                            "secondaryPath": "",
                            "depth": "0"
                        }
                    }
                }]
            }
        }, {
            "telemetryDestGroup": {
                "attributes": {
                    "id": "20",
                    "rn": "dest-20"
                },
                "children": [{
                    "telemetryRtDestGroupRel": {
                        "attributes": {
                            "rn": "rtdestGroupRel-[sys/tm/subs-30]",
                            "tCl": "telemetrySubscription",
                            "tDn": "sys/tm/subs-30"
                        }
                    }
                }, {
                    "telemetryDest": {
                        "attributes": {
                            "addr": "1.2.3.4",
                            "enc": "GPB",
                            "port": "50001",
                            "proto": "gRPC",
                            "rn": "addr-[1.2.3.4]-port-50001"
                        }
                    }
                }]
            }
        }, {
            "telemetrySubscription": {
                "attributes": {
                    "id": "30",
                    "rn": "subs-30"
                },
                "children": [{
                    "telemetryRsDestGroupRel": {
                        "attributes": {
                            "rType": "mo",
                            "rn": "rsdestGroupRel-[sys/tm/dest-20]",
                            "tCl": "telemetryDestGroup",
                            "tDn": "sys/tm/dest-20",
                            "tType": "mo"
                        }
                    }
                }, {
                    "telemetryRsSensorGroupRel": {
                        "attributes": {
                            "rType": "mo",
                            "rn": "rssensorGroupRel-[sys/tm/sensor-10]",
                            "sampleIntvl": "5000",
                            "tCl": "telemetrySensorGroup",
                            "tDn": "sys/tm/sensor-10",
                            "tType": "mo"
                        }
                    }
                }]
            }
        }]
    }
}

Filter Conditions on BGP Notifications

The following example payload enables notifications that trigger when the BFP feature is disabled as per the filterCondition attribute in the telemetrySensorPath MO. The data is streamed to10.30.217.80 port 50055. 

POST  https://192.168.20.123/api/node/mo/sys/tm.json

Payload:
{
  "telemetryEntity": {
    "children": [{
      "telemetrySensorGroup": {
        "attributes": {
          "id": "10"
        }
        "children": [{
          "telemetrySensorPath": {
            "attributes": {
              "excludeFilter": "",
              "filterCondition": "eq(fmBgp.operSt,\"disabled\")",
              "path": "sys/fm/bgp",
              "secondaryGroup": "0",
              "secondaryPath": "",
              "depth": "0"
            }
          }
        }
        ]
      }
    },
    {
      "telemetryDestGroup": {
        "attributes": {
          "id": "20"
        }
        "children": [{
          "telemetryDest": {
            "attributes": {
              "addr": "10.30.217.80",
              "port": "50055",
              "enc": "GPB",
              "proto": "gRPC"
            }
          }
        }
        ]
      }
    },
    {
      "telemetrySubscription": {
        "attributes": {
          "id": "30"
        }
        "children": [{
          "telemetryRsSensorGroupRel": {
            "attributes": {
              "sampleIntvl": "0",
              "tDn": "sys/tm/sensor-10"
            }
          }
        },
        {
          "telemetryRsDestGroupRel": {
            "attributes": {
              "tDn": "sys/tm/dest-20"
            }
          }
        }
        ]
      }
    }
    ]
  }
}

Using Postman Collection for Telemetry Configuration

An example Postman collection is an easy way to start configuring the telemetry feature, and can run all telemetry CLI equivalents in a single payload. Modify the file in the preceding link using your preferred text editor to update the payload to your needs, then open the collection in Postman and run the collection.

Telemetry Model in the DME

The telemetry application is modeled in the DME with the following structure: 


model
|----package [name:telemetry]
    |  @name:telemetry
    |----objects
         |----mo [name:Entity]
              |    @name:Entity
              |      @label:Telemetry System
              |--property 
              |    @name:adminSt
              |      @type:AdminState
              |
              |----mo [name:SensorGroup]
              |    |    @name:SensorGroup
              |    |      @label:Sensor Group
              |    |--property
              |    |    @name:id [key]
              |    |      @type:string:Basic
              |    |    @name:dataSrc
              |    |      @type:DataSource
              |    |
              |    |----mo [name:SensorPath]
              |         |   @name:SensorPath
              |         |     @label:Sensor Path
              |         |--property
              |         |    @name:path [key]
              |         |      @type:string:Basic
              |         |    @name:filterCondition
              |         |      @type:string:Basic
              |         |    @name:excludeFilter
              |         |      @type:string:Basic
              |         |    @name:depth
              |         |      @type:RetrieveDepth
              |
              |----mo [name:DestGroup]
              |    |    @name:DestGroup
              |    |      @label:Destination Group
              |    |--property
              |    |    @name:id
              |    |      @type:string:Basic
              |    |        
              |    |----mo [name:Dest]
              |         |   @name:Dest
              |         |     @label:Destination
              |         |--property
              |         |    @name:addr [key]
              |         |      @type:address:Ip
              |         |    @name:port [key]
              |         |      @type:scalar:Uint16
              |         |    @name:proto
              |         |      @type:Protocol
              |         |    @name:enc
              |         |      @type:Encoding
              |
              |----mo [name:Subscription]
                   |    @name:Subscription
                   |      @label:Subscription
                   |--property
                   |    @name:id
                   |      @type:scalar:Uint64
                   |----reldef
                   |    |  @name:SensorGroupRel
                   |    |    @to:SensorGroup
                   |    |    @cardinality:ntom
                   |    |    @label:Link to sensorGroup entry
                   |    |--property
                   |         @name:sampleIntvl
                   |           @type:scalar:Uint64
                   |
                   |----reldef
                        |  @name:DestGroupRel
                        |    @to:DestGroup
                        |    @cardinality:ntom
                        |    @label:Link to destGroup entry

DNs Available to Telemetry

For a list of DNs available to the telemetry feature, see Streaming Telemetry Sources.