Oracle WebLogic Server Basic Concepts

WebLogic Server Overview Topology, Configuration and Administration Oracle WebLogic Server

Agenda Topology Domain Server Admin Server Managed Server Cluster Node Manager Machine Configuration Files Administration Tools Sample Configuration Schemes

Domain What is it? a logically related group of WebLogic Server instances that you manage from a single set of configuration artifacts. What’s in a domain? Servers Clusters of servers Rules: All WebLogic Server instances within the same domain must be at the same major and minor version. Servers within a domain can be at different Maintenance Pack levels as long as the Administration Server is at the same Maintenance Pack Level or higher than its Managed Servers. config.xml

Server What is it? A configured instance to host applications and resources WebApps, Enterprise Apps, Web Services, … JMS, JDBC, Diagnostics, … What types of servers are there? Administration Server Managed Server JNDI JMS Queue JDBC Pool

Administration Server What is it? Central configuration controller for the entire domain What else does it do? Hosts the Administration Console Enables you to start and stop servers from a central location Enables you to migrate servers and services within the domain Enables you to deploy applications within the domain Guidelines: There must be exactly one* Administration Server in domain An Administration Server controls only one domain. For production use, we recommend not hosting application logic or resources on the Administration Server *The Administration Server does not need to run at all times, but is required for making configuration and deployment changes to a running domain. Managed Servers Admin Console Admin Server config.xml

Managed Server What is it? A running instance that hosts applications and resources needed by those applications - The real work horses in a WebLogic domain Each Managed Server is independent of all other Managed Servers in the domain (unless they are in a cluster, defined later) You can have as many Managed Servers in a domain as you need Individual Managed Servers are typically added for capacity and application isolation JNDI JMS Queue JDBC Pool

Administration Server to Managed Server Interaction The Administration Server stores the master copy of the domain configuration, including the configuration for all managed servers in the domain Each Managed Server stores a local copy of its configuration. When a Managed Server starts, it connects to the Administration Server to synchronize the configuration When configuration is changed, the Administration Server sends changed configuration to Managed Servers

Cluster A cluster is a group of Managed Servers running simultaneously and working together to provide increased scalability and reliability Scalability: through parallelism Reliability/Availability: through replication and redundancy A cluster appears as a single instance to most clients. Clusters enable some advanced features, such as Whole Server Migration, Service Migration, and clustered JMS destinations. Cluster 1 Cluster 2 Admin Svr

Cluster Guidelines All servers in a cluster must also be in the same domain. All servers within a cluster must be at the same Maintenance Pack level. Clustered servers can be on the same or different machines. You can have multiple clusters in a domain.

Load Balancing in a Cluster For JSPs and Servlets: load balancing is external Web server proxy plug-in (round robin) HTTP Proxy servlet (i.e., using WLS as a load balancer) 3 rd party hw or sw load balancer EJBs and RMI Objects: load balancing is done at connection Objects are cluster-aware Load balancing algorithm is stored in the clustered object’s stub Objects are available on all cluster members; remote objects connect/use according the LB algorithm in the stub Load balancing algorithms: Round robin, weighted, random, server affinity

Failover in a Cluster Servlets and JSPs: HTTP session state is replicated to a secondary server in the cluster or to a database EJBs and RMI Objects: Replicas available throughout the cluster Exceptions caught and retried on another instance For Stateful Session Beans, state is replicated on a secondary server

Communication in a Cluster Peer to Peer using Sockets - used for: Accessing non-clustered objects deployed to another clustered server instance on a different machine. Replicating HTTP session states and stateful session EJB states between a primary and secondary server instance. Accessing clustered objects that reside on a remote server instance. Peer to Peer using Unicast or Multicast - used for: Cluster-wide JNDI updates Heartbeats Cluster-wide JNDI tree Lists local resources and resources available throughout the cluster List is maintained on all servers in the cluster

Node Manager Utility/process running on a physical server that enables you to start, stop, suspend, and restart WebLogic Server instances remotely Must run on each physical server that hosts WebLogic Server instances that you want to control with Node Manager Not associated with a domain. Can start any server instance that resides on the same physical server. Optional, but required to start/stop servers using the Administration Console Required for Whole Server Migration and for some configurations of Automatic Service Migration Admin Server Managed Server Node Manager

Machine A definition that identifies a particular, physical piece of hardware. A machine definition is used to associate a computer with the Managed Servers it hosts. Used by Node Manager in restarting a failed Managed Server Used by a clustered Managed Server in selecting the best location for storing replicated session data

Service Configuration Besides topology elements, you also configure the services in a domain that applications rely on: JMS, JDBC, Diagnostics, etc. General notion: Configure the service in the domain Target to specific servers or clusters An instance of the resource is created on each server specified

Domain Directory Domain name Start and stop scripts Root configuration for the domain Configuration files for WLDF, JDBC, JMS, and Security Pending configuration changes Subdirectory for each Managed Server in the domain

Configuration Files <domain (schema locations)> <name> wl_server </name> <security-configuration></security-configuration> <jta></jta> <server> <name> examplesServer </name> </server> <app-deployment></app-deployment> <jms-server></jms-server> <jms-system-resource></jms-system-resource> <jdbc-system-resource> <name> examples-demo </name> <target> examplesServer,managedServer-0 </target> <descriptor-file-name> jdbc/examples-demo-jdbc.xml </descriptor-file-name> </jdbc-system-resource> </domain> config.xml config.xml – central configuration file for a domain includes the configuration of each server instance, cluster, resource, and service in the domain. references additional XML files that are stored in subdirectories of the domain/config directory: JMS, JDBC, WLDF, and Security All files are based on schemas examples-demo-jdbc.xml <jdbc-data-source> <name> examples-demo </name> <jdbc-driver-params></jdbc-driver-params> <jdbc-driver-params></jdbc-driver-params> <jdbc-data-source-params></jdbc-data-source-params> </jdbc-data-source> references to other files

Two-Phase Configuration Changes Changes activated in batches: Reliability, consistency: Make (related) changes as a group Validate before making the change Activate or Roll back as a single unit( all changes on all servers General process: Get an edit lock make changes changes are stored in the pending directory activate your changes (with implicit validation through the Admin Console or WLST) changes are distributed to servers in the domain Two phases: prepare and commit Prepared on all servers; any failures will cause total rollback

Administration Tools Configuration Wizard GUI/scriptable tool to create and extend WebLogic domains Template based Administration Console Browser-based tool for configuring and monitoring domains, deploying applications, and controlling servers WebLogic Scripting Tool (WLST) Script or command line tool to do the same thing as the Administration Console and Configuration Wizard Note that we will cover details on WLST in a separate document weblogic.Admin Deprecated command line tool for configuring a domain Recommend using WLST instead weblogic.Deployer Command line tool for deploying applications

Configuration Wizard Wizard that walks you through domain creation off line Not intended to run against a running domain Requires a domain template WLS ships with a default template and templates for samples domains Customers and layered products can create their own templates Scriptable (aka “WLST Offline”) More info: http://e-docs.bea.com/common/docs100/confgwiz/index.html http://e-docs.bea.com/common/docs100/interm/config.html http://e-docs.bea.com/common/docs100/tempbuild/index.html http://e-docs.bea.com/common/docs100/tempref/index.html

Administration Console Graphical interface to configure, manage, monitor a domain One Administration Console for each domain The Administration Server in the domain hosts the Admin Console application Open the Admin Console with the following URL: http://host:port/console Typically in dev: http://localhost:7001/console Sample domains use weblogic/weblogic as the user name and password In WLS 10.3, the Admin Console application deploys lazily – on first use More info: http://e-docs.bea.com/wls/docs100/intro/console.html

WebLogic Scripting Tool (WLST) Scripting tool for administering a domain (create, configure, manage, monitor, deploy applications) Based on Jython, which is a pure Java implementation of Python Great for automating repetitive tasks Heavy use by customers and within BEA “ Record” feature in Admin console: record actions to a WLST script Two modes: Offline: analogous to the Configuration Wizard Online: analogous to the Administration Console More info: http://e-docs.bea.com/wls/docs100/config_scripting/index.html

Single Server/Development Configuration Single server acts as the Administration Server and as a host for applications Not recommended for production, but standard for development Admin Console JNDI JMS Queue JDBC Pool config.xml

Configuring for Application Isolation Deploy applications to their own servers Admin server on its own server (highly recommended) Each managed server on its own physical server A1 A2 A3 Admin Server Managed Server Node Manager

Configuring for Extreme Application Isolation Each application gets its own domain Admin server on its own server (highly recommended) Each managed server on its own physical server A1 A1 A1 A2 A2 A2 Domain 1 Domain 2

Configuring for High Availability Clustered servers for HA and scalability All managed servers in the same cluster are on different machines, although machines are frequently shared Admin Server Managed Server Node Manager A1 A2 A2 A2 A1 A1 A2 A1

Configuring for Perf and Utilization Multiple Managed Servers per machine All Managed Servers in one cluster Cluster replication scheme considers location in determining secondary Managed Servers A1 A1 A1 A1 A1 A1 A1 A1

Simplified Administration Multiple applications deployed to a single cluster Admin server on its own server (highly recommended) Single domain to manage A1 A2 A3 A1 A2 A3 A1 A2 A3

Summary WebLogic Server configuration is segmented by domain Each domain represents a configuration entity and uses one set of configuration artifacts Each domain has one Administration Server, and can have multiple managed servers and clusters Node Manager is a per-machine process used to start and stop WebLogic Server instances There are a number of administration tools available for configuring and managing a WebLogic domain: Config Wizard, Admin Console, WLST, weblogic.Deployer Admin Server Managed Servers config.xml Admin Console

Oracle WebLogic Server Basic Concepts

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Oracle WebLogic Server Basic Concepts