[LU-13055] add ability for named Changelog consumers

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.12.8, Lustre 2.15.0
• Assignee: Mikhail Pershin
• Reporter: Andreas Dilger

Description

Currently Lustre Changelog consumers are always named e.g. "cl1" or "cl14". It would be useful to be able to declare the changelog username (e.g. "cl-rbh" or "cl-audit") so that it is clear who the Changelog users are, and to avoid duplicate changelog registrations. Otherwise, it can happen that the original Changelog user registration can be lost, and the application registers a new user, and the old user causes the Changelog records to accumulate.

Issue Links

• is duplicated by: LU-8517 Changelog Users
• is duplicated by: LU-13338 add changelog mask per registered user
• is related to: LU-14699 changelog garbage collection is too lax
• is related to: LU-16268 per-server changelog mask change doesn't change effective mask in some cases
• is related to: LU-13338 add changelog mask per registered user

Comments

[Gerrit Updater]

"Andreas Dilger <[e-mail]>" merged in patch https://review.whamcloud.com/c/doc/manual/+/57435/
Subject: LU-13055 doc: add changelog_register name/mask
Project: doc/manual
Branch: master
Current Patch Set:
Commit: 49a66627ea6fd91d0fe475a031b5ba9fa8e6f7bd

[Gerrit Updater]

"Andreas Dilger <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/doc/manual/+/57435
Subject: LU-13055 doc: add changelog_register name/mask
Project: doc/manual
Branch: master
Current Patch Set: 1
Commit: a19e58c24a1a194358b242eab35e00534556aa07

[Olaf Weber (Inactive)]

For context, llapi_changelog_start() works by opening /dev/changelog-MDTnnnn and then llapi_changelog_recv() reads from the file descriptor. There is no obvious way to make the kernel side aware of which changelog user is reading the log, so some new mechanism would have to be added.

[Mikhail Pershin]

Andreas, right, mask is used to decide what record to write. As for processing case, if we know particular user doing that processing then I think it is possible to filter records