--exclude=<database list> command line option

Bug #688717 reported by Nick Pavey on 2010-12-10
14
This bug affects 3 people
Affects Status Importance Assigned to Milestone
Percona XtraBackup
Wishlist
Unassigned
2.0
Undecided
Unassigned
2.1
Wishlist
Unassigned
2.2
Wishlist
Unassigned
2.3
Wishlist
Unassigned

Bug Description

Hi Percona,

I've modified the innobackupex-1.5.1 tool to add the following features:

  * --exclude=<database list> command line option : Exclude certain databases from copying of .frm, .MRG, .MYD, .MYI, .TRG, .TRN, .ARM, .ARZ and .opt files
  * Added code to tolerate race condition in copying of .frm etc files
  * Added additional output to display more information on backups which don't complete 100% properly
  * minor code restructuring for readability

Given that this is open source, I thought I'd submit my modifications back to you, in case you feel like including them in a subsequent release.

Regarding the race condition, here's the scenario I'm trying to avoid

  1. MySQL server running during backup
  2. innobackupex in --no-lock mode, because I don't want to quiesce the database during the copy of .frm etc files
  3. In subroutine backup_files, a READDIR generates a list of all files to be copied to the backup area
  4. Copy starts, but can take a long time
  5. At some point after the READDIR but before to copy the active MySQL server receives a DROP TABLE command
  6. The associated files are removed, by the time innobackupex gets to try to do the copy
  7. innobackupex throws a fatal error, shutting down the backup

Depending on the use model of the database, this may or may not be a major issue. For us it is not, because the tables which come and go like this do not hold critical information - it's scratchpad information, essentially.

In this modification, I trap the return code for the 'cp' command (I also cover the scp and tar features, but in a different way) and make a note of which files could not be copied.

At the end of the backup process, the code displays which databases / files were either skipped (with --exclude) or were only partially copied. The exit code of innobackupex is modified so that only a 100% complete backup will return a zero exit code.

I will _try_ to attach a patch to this bug. If I can't do that, please contact me directly and I'll forward it along.

Regards,

Nick Pavey

Vadim Tkachenko (vadim-tk) wrote :

Assigned to core-longbow to prepare test-case

Changed in percona-xtrabackup:
status: New → Confirmed
assignee: nobody → Valentine Gostev (core-longbow)
assignee: Valentine Gostev (core-longbow) → nobody
assignee: nobody → Valentine Gostev (core-longbow)
Changed in percona-xtrabackup:
status: Confirmed → Triaged
importance: Undecided → Low
milestone: none → 1.6
Valentine Gostev (longbow) wrote :

Added test case to a linked branch.

1. Patch breaks streaming backup. (test xb_stream fails)
2. While using patched innobackupex with exclude option, backup is done, but innobackupex completes with exit code '1'

Changed in percona-xtrabackup:
importance: Low → Wishlist
status: Triaged → Incomplete
Changed in percona-xtrabackup:
milestone: 1.6 → none
Stewart Smith (stewart) on 2012-09-04
Changed in percona-xtrabackup:
assignee: Valentine Gostev (longbow) → nobody
tags: added: contribution
summary: - Possible patch for innobackupex-1.5.1 to add features?
+ --exclude=<database list> command line option
Alexey Kopytov (akopytov) wrote :

See also bug #1272329.

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