SUSE_template Jan 2014 v2_ks
Compute node HA
a.k.a. can pets survive in OpenStack?
Adam SpiersSenior Software Engineer, Cloud & High
[email protected]
OpenStack London Meetup, Wednesday 18th November
short update on upstream development
High Availability in
a typical OpenStack cloud today
Typical HA control plane in OpenStack
Pacemaker ClusterControl Node 1Node
DRBDPostgreSQLRabbitMQKeystoneGlanceNovaDashboardCinderNeutronDatabase
Cluster Node 1Node 2DRBD or shared storageDatabaseMessage
QueueServices ClusterNode 1Node 2Node
3OrchestrationKeystoneGlanceNovaDashboardCinderTelemetryNeutronMaximises
cloud uptime
Automatic restart of OpenStack controller services
Active/Active API services with load balancing
DB + MQ either Active/Active or Active/Passive
Under the covers
Services ClusterNode 1Node 2Node 3Recommended by
official HA guide
HAProxy distributes service requests
Pacemakermonitoring and control of nodes and services
Corosynccluster membership / messaging / quorum / leadership
election
Corosync
PacemakerHAProxyBut what I really want to do is keep my
workloads up!
Why do we need HA for compute nodes?
HA Cluster
Control node
OSMessage queueDatabaseIdentityImagesBlock
storageNetworkingDashboardCompute
OSCompute node
nova-computelibvirt
HA only on control plane
OSCompute node
nova-computelibvirt
OSCompute node
nova-computelibvirt
HA Cluster
Control node
OSMessage queueDatabaseIdentityImagesBlock
storageNetworkingDashboardCompute
OSCompute node
nova-computelibvirt
Can we simply extend the cluster?
OSCompute node
nova-computelibvirt
OSCompute node
nova-computelibvirt
Scaling up
Corosync requires
