cloudstack/systemvm
Will Stevens ebc70a51e2 Merge pull request #1486 from remibergsma/reimplement-vrrp-setting-47
Reimplement router.redundant.vrrp.interval settingGlobal setting `router.redundant.vrrp.interval` is not used any more and it is now set to a hardcoded 1.

This results in a failover from master->backup when the backup doesn't hear from the master in ~3.6sec. This is a bit too tight, as we've seen failovers during live migrations. We could reproduce it in about half of the cases. Setting this to setting to 2 (tested it by hardcoding it in the systemvms) gives twice as much time and we didn't see issues any more. Instead of updating the hardcoded setting from 1 to 2, I reimplemented the global setting by sending it to the router with the cmd_line, as the non-VPC router also does.

Background:
Why is the maximum failover time in the example 3.6 seconds? This comes from the advertisement interval and the skew time. The default advertisement interval is 1 second (configurable in keepalived.conf). The skew time helps to keep everyone from trying to transition at once. It is a number between 0 and 1, based on the formula (256 - priority) / 256

As defined in the RFC, the backup must receive an advertisement from the master every (3 * advert_int) + skew_time seconds. If it doesn't hear anything from the master, it takes over. With a backup router priority of 100 (as in the example), the failover will happen at most 3.6 seconds after the master goes down.

Source: http://www.hollenback.net/KeepalivedForNetworkReliability

* pr/1486:
  Configure rVPC for router.redundant.vrrp.interval advert_int setting
  Have rVPCs use the router.redundant.vrrp.interval setting

Signed-off-by: Will Stevens <williamstevens@gmail.com>
2016-05-18 15:52:38 -04:00
..
bindir Move the system vm to a separate maven project. 2013-09-20 18:31:02 +08:00
certs Move the system vm to a separate maven project. 2013-09-20 18:31:02 +08:00
conf CLOUDSTACK-9062: Improve S3 implementation. 2015-11-19 15:29:10 +01:00
conf.dom0 CLOUDSTACK-9105: Logging enhancement: Handle/reference to track API calls end to end in the MS logs 2015-12-04 12:45:57 +05:30
css console-proxy add support of AltGr key and FR azerty keyboard 2014-12-08 18:05:43 +05:30
distro CLOUDSTACK-6220: Take 2, Fix cloudstack init scripts so that they 2014-03-10 16:11:52 -06:00
images Move the system vm to a separate maven project. 2013-09-20 18:31:02 +08:00
js console-proxy add support of AltGr key and FR azerty keyboard 2014-12-08 18:05:43 +05:30
libexec Move the system vm to a separate maven project. 2013-09-20 18:31:02 +08:00
patches/debian Merge pull request #1486 from remibergsma/reimplement-vrrp-setting-47 2016-05-18 15:52:38 -04:00
scripts Merge branch 'volume-upload' into master 2015-04-29 11:12:53 +05:30
test/python Fixed defaultroute on VPC routers in CsRoute and CsAddress 2015-08-24 13:35:29 +02:00
ui Move the system vm to a separate maven project. 2013-09-20 18:31:02 +08:00
vm-script Move the system vm to a separate maven project. 2013-09-20 18:31:02 +08:00
pom.xml Updating pom.xml version numbers for release 4.7.2-SNAPSHOT 2016-01-26 09:33:56 +01:00
systemvm-descriptor.xml Remove duplicate scripts and move the remaining items to the systemvm project 2013-10-14 08:02:35 +02:00