openstack
/
tripleo-heat-templates
Code Issues Proposed changes

Optimize kernel neighbour table for large scale environments 

Changing the default values of neighbor table (also known as ARP table)
in the kernel to avoid neighbour table overflow and thus fix
communication errors between overcloud nodes.
default kernel values support L2 network up to 1024 hosts (/22).
The patch will allow up to 4096 hosts (/20).

Change-Id: I5fabc766dd75a38cd3d835deee7e168f04dd30ce
Closes-Bug: #1690087
This commit is contained in:
Or Idgar 2017-05-11 08:32:17 +00:00
parent 6c43d5b4ff
commit 1651a1805a
1 changed files with 29 additions and 0 deletions
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29
puppet/services/kernel.yaml
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@ -26,6 +26,28 @@ parameters:
default: 0
description: Configures sysctl net.ipv6.{default/all}.disable_ipv6 keys
type: number
NeighbourGcThreshold1:
default: 1024
description: Configures sysctl net.ipv4.neigh.default.gc_thresh1 value.
This is the minimum number of entries to keep in the ARP
cache. The garbage collector will not run if there are
fewer than this number of entries in the cache.
type: number
NeighbourGcThreshold2:
default: 2048
description: Configures sysctl net.ipv4.neigh.default.gc_thresh2 value.
This is the soft maximum number of entries to keep in the
ARP cache. The garbage collector will allow the number of
entries to exceed this for 5 seconds before collection will
be performed.
type: number
NeighbourGcThreshold3:
default: 4096
description: Configures sysctl net.ipv4.neigh.default.gc_thresh3 value.
This is the hard maximum number of entries to keep in the
ARP cache. The garbage collector will always run if there
are more than this number of entries in the cache.
type: number
outputs:
role_data:
@ -86,5 +108,12 @@ outputs:
value: 1
fs.suid_dumpable:
value: 0
#avoid neighbour table overflow on large deployments
net.ipv4.neigh.default.gc_thresh1:
value: {get_param: NeighbourGcThreshold1}
net.ipv4.neigh.default.gc_thresh2:
value: {get_param: NeighbourGcThreshold2}
net.ipv4.neigh.default.gc_thresh3:
value: {get_param: NeighbourGcThreshold3}
step_config: |
include ::tripleo::profile::base::kernel