What is a cluster? What is High Availability and Fail over?
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Answer / shrinath
A weblogic server cluster consists of multiple weblogic
server server instances running simultaneously working
together to provide increased scalability and reliability.
A cluster appears to clients to be a single weblogic server
instance. the server instances that constitute a cluster can
run on the same machine or be located on different machines.
you can increase a cluster's capacity by adding additional
server instances to the cluster on an existing machine or
you can add machines to the cluster to host the incremental
server instances. Each instance in a cluster must run the
same version of Weblogic Server.
HIGH AVAILABILITY:- In a weblogic server cluster,
application processing can continue when a server instance
fails. You "cluster " application components by deploying
them on multiple server instances in the cluster-so, if a
server instance on which a component is running fails,
another server instance on which that component is deployed
can continue application processing.
Fail Over:-simple put failover means that when an
application component doing a particular job some set of
processing tasks-becomes unavailable for any reason, a copy
of the failed object finishes the job. Web logic server uses
standards based communication techniques and facilities
including IP sockets and the java Naming and Directory
Interface (JNDI) to share and maintain information about the
availability of objects in a cluster.
| Is This Answer Correct ? | 5 Yes | 0 No |
Answer / supreet yadav
WebLogic Server instances in a cluster detect failures of
their peer server instances by monitoring:
* Socket connections to a peer server
* Regular server heartbeat messages
In clusters that utilize Web servers with WebLogic proxy
plug-ins, the proxy plug-in handles failover transparently
to the client. If a server fails, the plug-in locates the
replicated HTTP session state on a secondary server and
redirects the client's request accordingly.
For clusters that use a supported hardware load balancing
solution, the load balancing hardware simply redirects
client requests to any available server in the WebLogic
Server cluster. The cluster itself obtains the replica of
the client's HTTP session state from a secondary server in
the cluster.
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / ramu2k20
ctuster is a group of managed server act as a single server
is called a cluster.
High availability:high availability is the guaranty of the
availability of the application server in a weblogic server
cluster application processing can continue when server
instance fails.By deploying multiple server instance in a
cluster. so if a server instance on which the component is
running fails. Another server instance on which the
component is deployed can continue application processing.
Fail Over:To distribute the request across all members of
the clusters, according to the workload on each server.
| Is This Answer Correct ? | 1 Yes | 0 No |
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