continue processing. Workload is distributed among Web containers and EJB containers in a cluster using a weighted round-robin scheme. Figure 3-6 illustrates the basic components of an application server in a distributed server environment. Cell Deploym ent Manager Adm in UI HTTP(s) Adm in application Adm in Service Nam e Server (NDI) SOAP or RMI/IIOP Master repository (file) Scripting client Node Node Agent Adm in Service Application Server W eb browser client W eb container HTTP server W ebSphere plug-in HTTP(s) Em bedded HTTP server SO AP (W eb Services) engine UDDI registry Config repository (file) Session Database application (EAR) Client container Java client RMI/IIOP EJB container Admin service Web Services Gateway JCA services Application Database Name server (JNDI) Security server m anaged by external provider (W ebSphere MQ) Msg Queue Msg Queue m anages JMS, MQ Messaging engine Figure 3-6 Distributed server environment 3.5 Cells, nodes and servers Regardless of the configuration, the WebSphere Application Server is organized based on the concepts of cells, nodes and servers. While all these elements are present in each configuration, cells and nodes do not play an important role until you start taking advantage of the features provided with Network Deployment. Chapter 3. Product overview 61