Project

General

Profile

Bug #6922

mon: do not allow unreasonable PG splitting

Added by Greg Farnum over 5 years ago. Updated over 5 years ago.

Status:
Resolved
Priority:
Normal
Assignee:
Category:
Monitor
Target version:
Start date:
12/02/2013
Due date:
% Done:

0%

Source:
Support
Tags:
Backport:
emperor
Regression:
No
Severity:
Reviewed:
Affected Versions:
ceph-qa-suite:
Pull request ID:

Description

We've had two different kinds of issues with PG splits:
1) the incorrectly-interpreted PG values from the Dumpling->Emperor upgrade (with a Dumpling leader) causing creation of millions of PGs,
2) Users splitting by a 255x multiple within a pool.

This causes issues with the OSD of various kinds; the first one for obvious reasons and the second one because the OSD internals are simply not designed to handle a sufficiently-large number of multiples in one go. In particular, in reproducing (2) locally I saw it taking 4 minutes to process the splits, during which time the internal heartbeating failed while waiting for stuff to get into the queue (which was at the default 50-op limit). To deal with both issues, have the monitors specify a maximum PG split ratio and enforce it.


Related issues

Related to Ceph - Fix #6908: OSD: do not do PG creates in-line with incoming request Rejected 11/27/2013

Associated revisions

Revision f57dad64 (diff)
Added by Greg Farnum over 5 years ago

OSDMonitor: prevent extreme multipliers on PG splits

Fixes: #6922
Backport: emperor

Signed-off-by: Greg Farnum <>

Revision c0c4448d (diff)
Added by Greg Farnum over 5 years ago

OSDMonitor: prevent extreme multipliers on PG splits

Fixes: #6922
Backport: emperor

Signed-off-by: Greg Farnum <>
Reviewed-by: Sage Weil <>
(cherry picked from commit f57dad6461171c903e8b5255eaed300374b00e74)

Conflicts:

src/mon/OSDMonitor.cc

History

#1 Updated by Greg Farnum over 5 years ago

  • Status changed from In Progress to Need Review
  • Backport set to emperor

#2 Updated by Greg Farnum over 5 years ago

Hrm, a customer has asked that we backport this patch to dumpling as well; is that sort of UI change appropriate on an established version?

#3 Updated by Greg Farnum over 5 years ago

  • Target version changed from v0.73 to v0.74

#4 Updated by Sage Weil over 5 years ago

  • Tracker changed from Fix to Bug
  • Status changed from Need Review to Pending Backport

#6 Updated by Greg Farnum over 5 years ago

  • Status changed from Pending Backport to Resolved

Sam merged this.

Also available in: Atom PDF