# Archive metadata

- Institution: CERN
- Department: HEP Computing
- Speaker: Julien Leduc
- Year: 2024
- Language: English
- Subjects: Computer science
- Source: [CERN](https://videos.cern.ch/record/3004520)
- 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 software and service have been designed to match the Run-3 write performance requirements at WLCG Tier-0. The queuing system, coupled with a small SSD-based cache, has demonstrated its performance predictability over the first two years of the run.

This performance was achieved with FIFO scheduling, resulting in a pure temporal collocation on tapes, with only the legacy "storage class" concept to separate data into different tape pools.

As tape data is becoming "warmer" in experiment data workflows, the performance of data retrieval from tape is becoming more important. Optimising retrieval requires additional metadata to deliver staging efficiency gains, which can be exploited in the evolution of the CTA tape scheduler.

This presentation will focus on various scheduling issues observed during Run-3, and how archive metadata will enable improvements to the CTA tape site write and read efficiencies..

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## Lectures

1. [Archive metadata](https://invisiblenetwork.ai/learn/cern/3004520/c570929c50a2), 27 min (CERN's player)