Q) Weblogic Architecture
When we install weblogic server, first thing it ask to
create domain. (base_domain)
Q) What is domain?
-> Domain is a collection of logical grouping of
resources and services and consist of Administration server, Managed
server and cluster.
->There can only be one admin server and zero-n
Managed servers in domain.
->These total domain information is stored
in config.xml file.
->A domain is cluster of weblogic pices, they are group
together to make logically easy for u to administrator.
-> Domain is Logical Group of web logic server instances
that we manage from a single set of configuration artefact’s.
-> It allow for a single point of administrator for a
collection of servers.
Different environment like development, test, production.
Nature of application deployed/supported like SOA, OSB
BAM.
-> A domain is the basic administration unit for
WebLogic Server instances. i.e. Domains include a special WebLogic Server
instance called the Administration
Server, which is the central point from which you configure and manage all
resources in the domain.
Note: Rule
All weblogic server instances within the same domain must be
at the same major and minor version.
Server within domain can be add different maintenance pack
level
Every
domain has Admin server
Managed Server
-> SOA is one managed server
-> OSB is one managed server
-> Portal is one managed server
Etc…
Suppose we installed SOA server, It will ask to create
domain. Either we can create new domain or we can give under base_domain.
Suppose we create new domain for SOA, lets say ”Soa_domain”
then it will create clone(copy) of admin server(weblogic server )
We can cluster two managed server together. And here when we deploy something in one
server it will auto reflect in other server.
Q) What Happens
if the Administration Server Fails?
The failure of an Administration Server does not affect the
operation of Managed Servers in the domain.
You can start a Managed Server even if the Administration
Server is not running.
Q) What is
Cluster in Weblogic ?
A cluster is a collection of multiple WebLogic
Server instances running simultaneously and working together to provide
increased scalability and reliability.
Weblogic Servers with in cluster can run on same machine or
different machines. These are also called as managed Server cluster.
In a cluster, most resources and services are deployed
identically to each Managed Server (as opposed to a single Managed Server),
enabling failover and load balancing.
Each server instance in a cluster must run the same version
of WebLogic Server.
A cluster appears to clients to be a single WebLogic Server
instance.
The key difference between clustered and nonclustered
Managed Servers is support for failover and load balancing.
Q) What
is cluster and how do you configure?
Cluster is a group of managed servers.
You need to provide the Multicast address, Multicast port,
Cluster Address which is nothing but the listen addresses, listen port of all
managed servers need to group together.
Using console
Using WLST
What is Dynamic Cluster in 12c?
Cluster that contain more one or more dynamic server.Servers is dynamically scaled up based on application need.
Q) What is
Weblogic?
WebLogic is a server software application that
runs on a middle-tier between the Database and related applications and
browser-based thin clients.
Q) What are
the WebLogic servers we have to manage?
There are two type of WebLogic Server instance in a domain
Administration Server and Managed Server.
The Administration Server is used for the administration
purpose and will not be used for deployments even if technically is
possible.
The Managed Servers are used for deployments.
ATTENTION:
Generally, when the WebLogic Administration Console is not
working, the WebLogic Admin Server is not working.
ATTENTION:
When we speak, starting the WebLogic Server generally is the
same as starting the Admin Server.
ATTENTION:
Starting the Application Server, generally is the same as
starting the WebLogic Managed Server.
Q) Things you should know before
creating domain in WebLogic Server?
Group of WebLogic Managed Server Instances that work
together to provide high availability and scalability for applications is
called cluster.
WebLogic Servers with in cluster can run on same
machine or different machines. These are also called as managed Server cluster.
You use configuration wizard to create or extend
domain but this can be used only in offline mode (when weblogic
server is not running)
You can also use WLST (WebLogic Scripting Tool),
command line tool to create and extend domains in WebLogic Server.
You can also use unpack command to create new
domain. This command can’t be used to extend domain.
Extending a domain means, you already created domain and now
wish to extend it (use more application, add managed server, create cluster…)
Configuration wizard can be run in Graphical Mode
(interactive GUI) or Console Mode (interactive text based)
For silent mode use WLST (WebLogic Scripting Tool)
While creating domain you specify Startup
Mode (Development or Production). In development mode, you
get autodeploy option and security is low.
In production mode
you need username/password to deploy applications.
When you create domain, it creates following directories
ii) bin
iii) config (config.xml for domain sits here)
iv) console-ext
v) lib
vi)security
vii) servers
You use config.cmd (windows)
or config.sh (unix) from $BEA_HOME/ wlserver_<ver>/
common/ bin to start configuration manager to create domain
Q) What is Administration
Server?
A domain
has one WLS instance configured as an admin server.
It is central configuration controller for the entire domain
-> It hosts the admin console.
-> Central
point of control of configuring and monitoring a domain.
-> Act a
repository for the xml configurations.
-> The
central source of logging information.
-> In a
domain, there can be only one admin server and one or more managed servers.
-> It enables us to start and stop
managed server from a central location
-> It enables us to migrate server
and services within the domain.
-> It enables us to deploy
applications within the domain.
-> In a domain,
there will be only one admin server and admin server controls only one domain.
-> It is
recommended not to host any application on admin server.
-> Administration
server used for configuration and maintenance.
-> You can deploy your application on administration
Server but it is recommended to create managed Server and deploy your
application in managed server and leave Administration domain for configuration
and maintenance.
-> Administration server is weblogic server instance
that maintains configuration data for a domain.
-> In weblogic, each domain will have one Administration
Server and Multiple Manage servers.
-> WebLogic Server allows you to quickly develop and
deploy reliable, secure, scalable and manageable applications. It manages
system-level details so you can concentrate on business logic and presentation.
WebLogic Admin
Server Details
Each WebLogic Server domain must have one server instance
that acts as the Administration Server.
An WebLogic Admin Server can administrate the WebLogic
domain, but it can act as a Managed Server as well.
However in Production environment a WebLogic Admin Server
must act only as an Admin Server.
The Administration Server is used all the time when you
configure all other server instances and resources in the domain.
This is why before you start the Managed Servers in a domain
you have to start the Administration Server.
ATTENTION
When you start a Managed Server, it contacts the
Administration Server for its configuration information.
. In this way, the Administration Server acts as the central
control entity for the configuration of the entire domain.
The failure of an Administration Server for a domain does
not affect the operation of Managed Servers in the domain.
WebLogic
Managed Server
-> Is an instance of weblogic server
-> It loads its configuration remotely from an
administration server.
-> All other WLS instances in a domain are called
Managed Servers. Managed servers host application components and resources.
->This is weblogic server where you deploy your
application
(Though you can deploy your application in Administration server as well but it is not recommended in production/UAT instance).
-> In a domain,
server instances other than the Administration Server are referred to
as Managed Servers.
-> Two or more Managed Servers can be
configured as a WebLogic Server cluster to increase application
scalability and availability.
-> In a WebLogic Server cluster, most resources and
services are deployed to each Managed Server (as opposed to a single Managed
Server) enabling failover and load balancing.
-> The servers within a cluster can run on the same
machine, or they can reside on different machines. To the client, a cluster
appears as a single Oracle WebLogic Server instance.
Q) What is EM ?
EM stands for Enterprise Manager. It is webpage we
deploy, test, monitor, diagnose and resolve problem for composites. It is
hosted on the Admin Server.
Q) What is soa-infra ?
soa-infra is a J2EE application that is targeted to
either a managed server or a cluster. All the composites gets deployed under
soa-infra application.
Q) What Is
Partition?
Sections of the SOA Infrastructure where we deploy SOA composite
applications known as partition.
When we install SOA suite tool, default partition get
created with name “default” but we can add as many as partitions as required.
Q)
What Are Benefits Of Partition?
1. Logically group SOA composites.
2. Perform bulk lifecycle management tasks on large numbers
of composites.
Q) What All
Bulk Operations We Can Perform On Partition?
1. Start all composites
2. Shut down all composites
3. Undeploy all composites
4. Retire all composites
5. Activate all composites
6. List all composites
Q) What All
Schema We Need For Oracle Soa Suite Tool ?
We require following schema.
1. MDS – This schema is used to store all the artefact’s
like WSDL, XML, XSD etc.
2. SOA_INFRA – This schema is used to
store SOA Component Engine properties, deployed composites, payloads, runtime
metadata etc.
3. ORABAM – This schema is used to store
the metadata that is related to BAM and its components and this is optional
schema.
4. ORASDPM – This schema is used to store
metadata about the user messaging systems.
Q) How we can deploy composite to
SOA server?
There are different methods to deploy SOA composite to SOA
server.
1. Through EM console
2. Directly from JDeveloper
3. Scripting (Ant, WLST etc.)
Q) What Is
Config Plan ?
Config plan is used during composite deployment.
"This is a xml file where we specify the parameters
that we want to replace while doing the deployment to next environment."
Q) Can We
Have Multiple Composites With Same Name On Soa Server ?
Yes, we can have multiple composites with same name on SOA
server but this is possible when we have composites with revisions.
Q) If
We Have Multiple Composites On Soa Server With Same Name Then How Composites
Run?
If we have multiple composites with same name then only one
composite will act as default composite which will run only. But we can go to
EM console and make other composite default.
Difference
between the production mode and development mode in Weblogic server?
Development
Mode:
->The Default JDK for development domain is Sun
jdk.
-> you can use the demo certificates for
SSL.
-> Auto deployment is enabled.
->server instances rotate their log files on
startup.
-> Admin server uses an automatically
created boot. Properties during startup.
-> The default maximum capacity for JDBC Data source is 15.
Production
Mode:
->The default JDK for production domain is
JRocket.
-> If you use the demo certificate for SSL
a warning is displayed.
-> Auto deployment is disabled.
-> server instance rotate their log files
when it reaches 5MB.
-> Admin server prompts for username and
password during startup.
-> The default maximum capacity for JDBC
Data source is 25.
What is
config.xml file?
This file specifies the configuration of each server
instance, cluster, resource and services in the domain.
This file located in
MW_HOME/user_projects/domains/doamin_name/config/config.xml(DOMAIN_HOME/config/config.xml)
"Each time the Administration server starts
successfully, a backup configuration file config.xml
booted file is created in domain directory."
How many
ways to startup the Weblogic server?
Weblogic server can be started in the following ways:
-> startWeblogic.sh
-> Using WLST and ANT scripts.
-> Node manager
-> Weblogic.Admin
start command
Start
the Administration Server (WebLogic Server)
To start the Admin server we have to run the following
command:
nohup $DOMAIN_HOME/bin/startWebLogic.sh > nohup.out
&
or if we are in the $DOMAIN_HOME/bin:
./startWebLogic.sh&
If a command is terminated by the control operator &, the shell executes the command in the background in a subshell. The shell does not wait for the command to finish, and the return status is 0.
Stop the
Administration Server (WebLogic Server)
To stop the Admin server we have to run the following
command under $DOMAIN_HOME/bin :
./stopWebLogic.sh&
When the WebLogic Admin Server is stopped, we cannot use
the WebLogic Administration Console.
In order to start that server from the Administration console, you must start the Node Manager first. That server must be associated with a machine as well.
Start a
Managed WebLogic Server
From WebLogic Administration Console you have to go to
the Environment -> Servers -> Control Tab. Check the Managed Server
you want to start and click on "Start"
Stop (Shutdown) WebLogic Managed Server
Stopping the Managed Server is similar with starting the
Managed Server. Instead pressing on "Start" we press on
"Shutdown" button. Here we can choose "When work complete"
or "Force shutdown now".
In order to avoid this problem, WebLogic introduce the
concept of Unit-of-Order. With this concept, more messages are associated with
an ID (UOO). The Message Unit-of-Order enforces the order of messages with
the same key so that the messages are consumed in the order they were added to
the queue.
queue = (Queue)(ctx.lookup(destName));
qsender = (WLMessageProducer) qs.createProducer(queue);
qsender.setUnitOfOrder();
uooname = qsender.getUnitOfOrder();
System.out.println("Using UnitOfOrder :" +
uooname);
How do
you troubleshoot if config.xml file will be deleted?
First we look for is there any last good backup of configuration is available on the Admin machine. If it is not found then alternatively you can find it on remote machines where the managed servers running.
Best practice is whenever there is a configuration changes made before and after you need to take a backup.That will help you such situation where you might need old configuration sometime.
How do u
trouble shoot if managed server is in FAILED state?
If any managed server is in FAILED state there could be
reasons as follows:
i) deployment failed
ii) JDBC DataSource issue
iii) JMS configuration issue
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