# Migrating CTA Frontend from XRootD/SSI to gRPC

- Institution: CERN
- Department: HEP Computing
- Speaker: Konstantina Skovola
- Year: 2025
- Language: English
- Subjects: Computer science
- Source: [CERN](https://videos.cern.ch/record/3022193)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

The CTA Frontend serves the physics workflow event requests made by the disk system buffer, for example EOS or dCache, and cta-admin commands submitted by operators and automated scripts. Communication with the frontend is currently based on XRootD/SSI. However, not all disk front-ends support the SSI extensions to XRootD, which creates a constraint for sites using CTA as a tape backend. As a result, we have decided to migrate CTA to a more widely-supported protocol. This talk will present the ongoing work on migrating from XRootD/SSI to the industry-standard gRPC framework. We will present the implementation of the rpc methods, discuss how authentication works with gRPC vs XRootD/SSI and finally discuss the roadmap for completely switching to gRPC..

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## Lectures

1. [Migrating CTA Frontend from XRootD/SSI to gRPC](https://invisiblenetwork.ai/learn/cern/3022193/abf3a0cc04f2), 14 min (CERN's player)