Cisco telemetry and monitoring with N9K

Hi all,

We're currently building a BGP EVPN fabric based on N9K (9300 as both spine and leaf), and we're exploring new ways to get some visibility in our datacenter (no, we're not aiming at Tetration or a netflow collector like LiveAction).

I've started exploring ELK as syslog, telemetry collector plus the option of running some custom scripts in NX-OS guestshell and uploading the results to the ElasticSearch cluster. However, I cannot think about some advanced data to gather - you know, something that will have an additional value to simple SNMP-style syslog and maybe telemetry (which is quite disappointing so far. very few sources, cli commands which don't support JSON cannot be exported as telemetry, and I can't really send interfaces stats like throughput).

Are you familiar with implementations of ELK as cisco monitoring solution? I'd love to see some advice (yes I know there's a lab in the DevNet) and examples or ideas to things you can monitor with custom scripts in guestshell etc...