Beginning with EFA 2.3.0, you can deploy
EFA in a two-node cluster for high availability.
Overview
A high-availability cluster is a group of servers that provide continuous up time, or
at least minimum down time, for the applications on the servers in the group. If an
application on one server fails, another server in the cluster maintains the
availability of the application.
In the following diagram, EFA is deployed in the TPVM running on SLX-OS. The two EFA
instances are clustered and configured with one IP address, so that clients need to
reach only one endpoint. All EFA services are installed on each node. The node on
which EFA is installed is the active node and processes all requests. The other node
is the standby.
All operations provided by EFA services must be idempotent, meaning they produce the same
result for multiple identical requests or operations. For more information, see the
"Idempotency" section of the
Extreme Fabric Automation Administration
Guide, 2.4.0
.
Two-node high-availability
deployment
PV: Persistent Volume
A piece of storage in the
cluster that was provisioned by an administrator.
PVC: Persistent Volume Claims
A request for storage,
similar to how a Pod requests compute resources.
Brick
The basic unit of storage in
GlusterFS, represented by an export directory on a server in the trusted
storage pool.
SC: Storage Class
A description of the
“classes” of storage in a Kubernetes realm.
SVC: Kubernetes Service
A logical set of Pods and a
policy by which to access them.
ING: Kubernetes Ingress
A collection of routing rules
that govern how external users access services running in a Kubernetes
cluster.
RS: Kubernetes Replica Sets
Ensures how many replicas of
a Pod should be running.
K3s
Manages the life cycle of the
EFA services in failover or fallback scenarios.
Traefik
An embedded ingress
controller (load balancer) packaged with K3s.
GlusterFS
A high-availability
replicated volume that maintains the persistent storage for the K3s cluster,
the EFA database, and EFA logs.
MariaDB
A database service deployed
outside of the K3s cluster in active-standby mode.
RabbitMQ
A messaging service deployed
in the cluster in active-active mode.
Services in high-availability mode
EFA services running on K3s are in active-active mode or active-standby mode, depending on the
design of the service.
