Cisco_telemetry_mdt input plugin incorrect parsing of data sent by sensor "Cisco-IOS-XR-qos-ma-oper:qos/interface-table/interface/input/service-policy-names/service-policy-instance/statistics"

[marioullio]

Relevant telegraf.conf:

[[inputs.cisco_telemetry_mdt]]
 ## Telemetry transport can be "tcp" or "grpc".  TLS is only supported when
 # ## using the grpc transport.
   transport = "grpc"
 #
 #   ## Address and port to host telemetry listener
     service_address = "163.162.220.100:54321"

System info:

Operating system: redhat:enterprise_linux 7.6

Steps to reproduce:

1. Cisco equipment details
   Cisco IOS XR Software, Version 6.6.25
   Copyright (c) 2013-2019 by Cisco Systems, Inc.
   Build Information:
   Built By : deenayak
   Built On : Wed May 29 06:42:35 PDT 2019
   Built Host : iox-lnx-030
   Workspace : /auto/srcarchive13/prod/6.6.25/ncs560/ws
   Version : 6.6.25
   Location : /opt/cisco/XR/packages/
   cisco NCS-560 () processor

2. Relevant Cisco equipment configuration
   telemetry model-driven
   destination-group DGroup1
   address-family ipv4 163.162.220.100 port 54321
   encoding self-describing-gpb
   protocol grpc no-tls
   !
   !
   sensor-group SGroup
   sensor-path Cisco-IOS-XR-qos-ma-oper:qos/interface-table/interface/input/service-policy-names/service-policy-instance/statistics
   !
   subscription Sub1
   sensor-group-id SGroup sample-interval 300000
   destination-id DGroup1
   source-interface Loopback0
   !

3. Send the telegraf output to file

Expected behavior:

All the metrics included in the output of Pipeline Collector (see dump.pipeline.txt) are also included in Telegraf output.

dump.pipeline.txt

Actual behavior:

In the Telegraf output only the "default class" metrics are included. It seems that Telegraf is not understanding correctly that "class-stats_PIPELINE_EDIT" is an array.

dump.telegraf.txt

Additional info:

[sbyx]

The problem seems to be that the device does not declare the class-name to be a key therefore the telegraf plugin doesnt know to differentiate the measurements.

Does it make a difference if you change the subscription from "Cisco-IOS-XR-qos-ma-oper:qos/interface-table/interface/input/service-policy-names/service-policy-instance/statistics" to "Cisco-IOS-XR-qos-ma-oper:qos/interface-table/interface/input/service-policy-names/service-policy-instance/statistics/class_stats"?

[marioullio]

Changing the configuration as subjected results in an invalid configuration RP/0/RP1/CPU0:RONALDO-RF2#show telemetry model-driven sensor-group Sat Aug 31 22:31:45.833 CEST Sensor Group Id:SGroup Sensor Path: Cisco-IOS-XR-qos-ma-oper:qos/interface-table/interface/input/service-policy-names/service-policy-instance/statistics/class_stats Sensor Path State: Not Resolved Status: Invalid sensor path

[sbyx]

There should be a changeset now merged that should allow you to specify the extra key-field so that the nested structure is parsed corretly. See the embedded_keys option in latest commits.

[yoplin]

How did you fix this? We're having the exact same problem with telegraf version 1.22.4