# EPF5 Week-18: Building a Histogram for Teku

## Week overview
- [X] Continued work on Lighthouse PR after the review
- [X] Compared Lighthouse and Prysm metrics
- [X] Collaborated with Hangleang on Grandine metrics overview
- [X] Discussed metric corrections with Prysm
- [X] Updated the Besu metrics library in Teku
- [X] Encountered issues building a histogram on Besu due to library limitations
- [X] Attended a local crypto event, met with the Lido team to discuss staking and running validator nodes

This week focused on implementing a histogram for Teku. I also attended a local crypto conference and continued collaborating with other CL clients on PeerDAS metrics.

### Kurtosis
My [PR with PeerDAS dashboard](https://github.com/ethpandaops/ethereum-package/pull/790) was merged into Kurtosis. I tested it, and it works fine. I used it frequently while working on Teku this week.

### CL clients
I worked with Hangleang on the Grandine dashboard, where we discussed how to use the supernode flag and apply filters for supernodes. After Lighthouse reviewed my PR, I continued discussions with João regarding its implementation. I also talked with Manu about Prysm’s metrics, which are implemented in milliseconds. Prysm uses millisecond-based buckets, which seems overly detailed. I shared the Prysm graphs, and we agreed they should be transformed into seconds.


## Teku
This week I collaborated closely with Dmitry on [implementing the histogram](https://github.com/Nashatyrev/teku/pull/160). I updated Teku’s Besu metrics-core library and tried different approaches to implement the histogram as needed. However, the library didn’t function as expected. Next week, I plan to continue working on the histogram implementation and discuss the possibility of updating the Besu library in the upcoming release.

## Weekly EPF Activity
- [EPF5 Standup]()

- [EPF5 Office Hours](https://github.com/eth-protocol-fellows/cohort-five/issues/488)
AMA with Andrew Ashikhmin, core developer and CTO at Erigon, Ethereum Execution Layer

- [ACDE #198](https://youtube.com/live/YQwdKE0d8LI)
[Github issue #1163](https://github.com/ethereum/pm/issues/1163)
Devnet-4, CL spec release v1.5.0-alpha.8, EIPs 7702, 7623, 7783

## TODO
- [ ] Implement the histogram in Teku
- [ ] Refactor the Lighthouse PR after the review
- [ ] Discuss metrics in the PeerDAS Breakout Room

## Links
[Engine API: A Visual Guide](https://hackmd.io/@danielrachi/engine_api)
[Data Structures in Execution Layer](https://epf.wiki/#/wiki/EL/data-structures)
[Kurtosis PeerDAS dashboard](https://github.com/ethpandaops/ethereum-package/blob/main/static_files/grafana-config/dashboards/peerdas-dashboard.json)