Bug 1266977 - ipset - Hash is full, cannot add more elements
Summary: ipset - Hash is full, cannot add more elements
Alias: None
Product: Red Hat OpenStack
Classification: Red Hat
Component: openstack-neutron
Version: 6.0 (Juno)
Hardware: x86_64
OS: Linux
Target Milestone: async
: 6.0 (Juno)
Assignee: Miguel Angel Ajo
QA Contact: Itzik Brown
Depends On:
TreeView+ depends on / blocked
Reported: 2015-09-28 17:30 UTC by Benjamin Schmaus
Modified: 2019-09-12 08:59 UTC (History)
10 users (show)

Fixed In Version: openstack-neutron-2014.2.3-16.el7ost
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2015-10-15 16:10:20 UTC
Target Upstream Version:

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Launchpad 1439817 0 None None None Never
OpenStack gerrit 173753 0 None None None Never
Red Hat Product Errata RHSA-2015:1909 0 normal SHIPPED_LIVE Moderate: openstack-neutron security and bug fix update 2015-10-15 20:09:00 UTC

Description Benjamin Schmaus 2015-09-28 17:30:10 UTC
Description of problem:

We have instances failing to boot because users are putting very large
subnets (e.g., /15) into allowed_address_pairs in Neutron.  It appears
that we're hitting some sort of 64K limit in the ipset implementation.

The users putting subnets into allowed_address_pairs, so it seems that
they should be stored in ipset as a subnet as well, not individual

This results in errors like from an instance booting:
2015-09-25 17:17:21.418 51840 INFO heat.engine.stack [-] Stack CREATE
FAILED (VMG-NEC2-OAMA-24ilgto3rllb): Resource CREATE failed: Error:
Server VMG-NEC2-OAM-A delete failed: (500) Build of instance
6031be29-f194-43fb-b05b-92e0c2d7cd18 aborted: Failed to allocate the
network(s), not rescheduling.

On the compute host, the neutron logs contain items like:
2015-09-25 12:04:13.129 58378 ERROR neutron.agent.linux.utils
[req-c8c2e2e2-1cc5-4fab-b1b6-b84f78043459 None]
Command: ['sudo', 'neutron-rootwrap', '/etc/neutron/rootwrap.conf',
'ipset', 'add', '-exist', 'IPv4c3742bfb-7f15-4c92-b', '']
Exit code: 1
Stdout: ''
Stderr: 'ipset v6.19: Hash is full, cannot add more elements\n'

We can see that the ipset hash is indeed near a 64K limit, if that is
[root@host nova]# ipset list | wc -l

We can see that the sets have a limit of 65536:
Name: IPv6f60f0540-fa6c-4a8d-9
Type: hash:ip
Revision: 1
Header: family inet6 hashsize 1024 maxelem 65536

Version-Release number of selected component (if applicable): OSP6

How reproducible:
100% in larger deployments

Steps to Reproduce:

Actual results:

Expected results:

Additional info:

Upstream bug: https://bugs.launchpad.net/neutron/+bug/1439817

Upstream code commit for OSP6: https://git.openstack.org/cgit/openstack/neutron/commit/?id=0325b98c54af276064e367db603bfeb525bbb790

Comment 12 Benjamin Schmaus 2015-10-09 15:21:03 UTC
Hotfix worked for my client where it was applied.

Comment 16 Itzik Brown 2015-10-15 11:06:20 UTC
Checked with openstack-neutron-2014.2.3-19.el7ost.noarch

Comment 18 errata-xmlrpc 2015-10-15 16:10:20 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.


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