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When Telemetry subscription is configured to push data related to interface on IOS-XE device, the device throws error logs such as: *Nov 19 20:26:05.586: %DBAL-4-LONG_EXEC_BATCH: R0/0: linux_iosd-image: Long exec [XX:XX] create:exec:now [XXXXXX:XXXXXX:XXXXXX] e:p [XXXX:XX] resumes [0] peer [BPROC_MDT_PUBD] *Nov 19 20:26:05.586: %DBAL-4-DELAYED_BATCH: R0/0: pubd: Delayed batch [XX:X] create:exec:notif:now [XXXXXX:XXXXXX:XXXXXX:XXXXXX] eproc [X] e:p [X:X] peer [BPROC_IOSD_RP] Eventually the logging buffer and syslog is filled with the error logs. The telemetry information is pushed with no apparently issues.
The issue was reported in IOS-XE 17.9.4 but other versions might be impacted. Telemetry subscription configuration example: telemetry ietf subscription 560 encoding encode-kvgpb filter xpath /interfaces-ios-xe-oper:interfaces/interface[name='GigabitEthernet1/0/5']/statistics source-address X.X.X.X source-vrf Mgmt-vrf stream yang-push update-policy periodic 1000 receiver ip address X.X.X.X 57344 protocol grpc-tcp The port channel does not have to be actively forwarding traffic. It is necessary that the port channel is created and associated to interfaces in the device such as: interface Port-channel1 switchport mode trunk switchport nonegotiate interface TenGigabitEthernet2/0/7 switchport mode trunk switchport nonegotiate channel-group 1 mode active interface TenGigabitEthernet2/0/8 switchport mode trunk switchport nonegotiate channel-group 1 mode active Other conditions are still under review.
The error logs can be filtered using a logging discriminator to filter DBAL error logs and applied to the required logging services: (config)#logging discriminator Telemetr facility drops DBAL (config)#logging buffered discriminator Telemetr (config)#logging console discriminator Telemetr (config)#logging monitor discriminator Telemetr
So far the error was reproduced on lab evironment with 17.9.4, other 17.9 releases and higher version can be affected. It was confirmed that 17.6.5 is not impacted by this issue. At this point there is no confirmation of impact in services or telemetry information. The telemetry data is pushed with no issues. The nature of the error log is related to an excesive time to iterate an internal database when the port-channel is configured looking for the data of the interface information in the xpath filter of the telemetry subscription. The tests were done ony with "filter xpath /interfaces-ios-xe-oper:interfaces/interface[name='GigabitEthernetX/X/X']/statistics" filter but might potentially affect other telemetry filters. If suspecting this bug consider to open a TAC case including "show tech" file for proper diagnosis.