CephFS Code Walkthroughs¶

The CephFS Code Walkthrough meetings will be used to establish a durable knowledge base for CephFS developers.

This weekly meeting will occur every Monday at 9 AM EDT at: https://meet.jit.si/cephfs-code-walkthroughs

• "Ceph Community calendar": https://ceph.io/contribute/#community-calendar
• "Google Calendar": https://calendar.google.com/calendar/b/1?cid=OXRzOWM3bHQ3dTF2aWMyaWp2dnFxbGZwbzBAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ
• "iCal": https://calendar.google.com/calendar/ical/9ts9c7lt7u1vic2ijvvqqlfpo0%40group.calendar.google.com/public/basic.ics

Developers may pick a topic from the below list or create their own.

Scheduled Topics¶

• 2024-04-02: Patrick: Monitor upgrades - sequence and handling feature compat
• 2023-06-12: Patrick: minor log segments (rescheduled due to recording uncertainty)

Open Topics¶

• High-level Overview of the MDS (overall design, function and flow)
• Capability Revoke
• Capability Grant
• cephfs-data-scan
• MDS Scrub
• MDS path traversal
• Client path traversal
• MDS Balancer (!Migration)
• MDS Migrator
• MDS Locker (break up as necessary, very large topic)
• MDS MDCache rejoin
• MDS MDCache resolve
• MDS CDir (directory fragment)
• MDS CDir Fragment/Merge
• MDS Subtree management
• MDS OpenFileTable
• MDS <-> MDS messages
• Client auth MDS picking for requests
• MDS Journal on-disk format (cephfs-journal-tool examples)
• MDS on-disk metadata format (CInode, CDir, CDentry)
• rstats
• MDS session map (reset too as part of disaster recovery)
• MDSMap/FSMap
• MDS journal trimming
• MDS Stray directory / hard link reintegration
• MDS stats reporting (MDSPinger/MetricAggregator/MetricsHandler)
• MDS Context (within MDS and Ceph in-general)
• osdc/Journaler
• osdc/Filer + osdc/ObjectCacher
• Snapshots

Past Topics¶

• 2022-05-16: Jeff: kernel client overview - https://www.youtube.com/watch?v=ecbtfgumG34
• 2022-01-24: Patrick: fs:upgrade suite
• 2021-11-22: Venky Shankar - MDS Locker, Part 2 - https://www.youtube.com/watch?v=Ah4H3apSvXw
• 2021-11-15: Jeff Layton - kclient overview - https://www.youtube.com/watch?v=kXFsDwoRuyM
• 2021-09-27: Patrick Donnelly - MDS Journal Machinery - https://www.youtube.com/watch?v=yB5JvIvZ764
• 2021-08-09: Milind Changire - rstats https://www.youtube.com/watch?v=85lnSSfXkBk
• 2021-07-26: Kotresh HR - MDS path traversal https://www.youtube.com/watch?v=dYJ84qpR0kY
• 2021-07-19: Venky Shankar - MDS Locker, Part 1 https://www.youtube.com/watch?v=jkWJ6x_Bz-s
• 2021-05-03: Patrick Donnelly - MDSMonitor https://www.youtube.com/watch?v=rUJZy-2jKOo
• 2021-04-26: Venky Shankar - cephfs-mirror daemon part 2: https://www.youtube.com/watch?v=oMs7appb20s
• 2021-04-19: Venky Shankar - CephFS Mirroring https://www.youtube.com/watch?v=nZSN1zkSXSs