Ecomm Enterprise High Availability Solution. Ecomm Enterprise High Availability Solution (EEHAS) Page 1 of 7

Transcription

1 Ecomm Enterprise High Availability Solution Ecomm Enterprise High Availability Solution (EEHAS) Page 1 of 7

2 Ecomm Enterprise High Availability Solution Table of Contents 1. INTRODUCTION OVERVIEW ARCHITECTURE CLUSTERING APPLICATION SERVERS Failover Load balancing Web server load balancing Application server load balancing Scalability Terminology DATABASE HIGH AVAILABILITY SUMMARY OF EEHAS PROCESS SUPPORTED TOPOLOGIES CONCLUSION Page 2 of 7

3 1. Introduction Organizations today face a tough challenge in choosing an appropriate high availability solution that meets their business requirements and IT budgets. Until recently, such solutions were based on proprietary systems, involved significant investment in capital, time, and resources to assemble, integrate, test, manage, and support. This scenario has been changed dramatically with the introduction of software-based high availability solutions. Our Ecomm Enterprise High Availability Solution (EEHAS) provides IBM software based high availability solutions for your e-applications with our strong technical expertise. EEHAS encompasses appropriate redundancy, provides adequate protection from all types of outages and ensure consistent high performance and availability. EEHAS provides a range of high availability solutions that fit every organization regardless of size. Small workgroups and global enterprises alike are able to extend the reach of their critical business applications. 2. Overview Choosing and implementing the architecture that best fits the availability requirements of a business can be a daunting task. The availability of business applications are often threatened by network overloads as well as server and application failures. Resource utilization is often out of balance, resulting in the low-performance resources being overloaded with requests while the highperformance resources remain idle. Server load balancing is a widely adopted solution to performance and availability problems. Our EEHAS should be driven by well-understood business requirements with the back bone of reliable IBM products. Features of EEHAS, Be transparent to most failures Provide built-in preventative measures Provide proactive monitoring and fast detection of failures Provide fast recoverability Centralized management Protect the data so that there is minimal or no data loss Implement the operational best practices to manage your environment Provide the high availability solution

4 3. Product Groups There are three product groups utilized in this solution. WebSphere Core for WebSphere Application Server Network Deployment, IM Data Management for DB2 Enterprise Server Edition and WebSphere for WebSphere Application Server. The specific components used per product is Network Deployment for WebSphere Application Server and High Availability Disaster Recovery for DB2. 4. Architecture 5. Clustering Application Servers in WAS ND A cluster is a group of Websphere ND application server instances, running simultaneously, that act like a single system enabling high availability and load balancing. EEHAS can be supported for both Horizontal and Vertical clustering, so client work can be distributed across several nodes. In a clustered environment, application server instances are server members of the cluster, all of whom must have identical application components deployed on them. However, other than the configured applications, cluster members do not have to share any other configuration parameters. By clustering, you can achieve one or more of the following benefits. How you implement clustering determines which benefits are achieved: Failover Load balancing

5 Scalability 5.1. Failover Failover allows one application server instance to act as a backup to a failed application server instance and resume processing the task, thereby enabling one application server to carry on processing Load balancing Load balancing is a technique used to distribute processing and communications activity evenly across a number of systems so that no single device is overwhelmed. If one server starts to get congested or overloaded, requests are forwarded to another server with more capacity Web server load balancing Web server load balancing is useful for queuing and throttling requests. According to requirements web server load balancing can be done through IBM Edge components and HTTP server Application server load balancing Application server load balancing is useful for managing the load between application server tiers. Application servers can be configured to use a weighted round-robin routing policy that ensures a balanced routing distribution based on the set of server weights that have been assigned to the members of a cluster. Application server load balancing is best used when balancing is needed between tiers Scalability Scalability in a cluster is the capability of an administrator to increase the capacity of the application dynamically to meet the demand without interrupting or negatively impacting service. Websphere ND clusters allow administrators to remove nodes from a cluster in order to upgrade components, such as memory, or to add nodes to the cluster without bringing down the cluster itself Terminology Websphere ND uses specific terminology, which is included here to avoid confusion:

6 server: Represents an instance of a Java virtual machine (JVM). node: Represents a physical system running one or more WebSphere servers. cell: Represents a physical grouping of multiple nodes for administrative purposes. cluster: Represents a logical grouping of multiple application servers within a cell for administration, application deployment, load balancing, and fail over purposes. federation: The process of joining a stand-alone WebSphere node to a WebSphere cell. 6. Database High Availability EEHAS using the advantages of HADR facility in DB2 ENTERPRISE SERVER for allowing replication of any logged database activity to a local or remote location. We can safely minimize the downtime to only a few seconds. HADR protects against data loss by continually replicating data changes from a source database, called the primary, to a target database, called the standby. Furthermore, you can seamlessly redirect clients that were using the original primary database to the standby database (which becomes the new primary database) by using Automatic Client Reroute (ACR) and retry logic in the application. This seamless redirection is also possible using software solutions discussed in other chapters, which can manage IP address redirection Passive (local) standby node: If the active primary node fails, the local standby node takes over the resources, including shared disk. HADR (remote) standby node: The node where the HADR standby database is running. When both active primary node and the passive standby node are not available, this node can provide service. HADR standby can be placed in the same local site as the other nodes, but it must be in a remote site for the purpose of disaster recovery.

7 7. Summary of EEHAS process Installing the web servers Installing the deployment manager Installing instances of Websphere Network Deployment Server Installing DB2 ENTERPRISE SERVER Creating the cluster Creating the federation of servers Starting the deployment manager Setting up the cluster Configuring the cluster members Starting the cluster Deploying applications Generating the WebSphere HTTP plug-in Configuring Load balance Configuring HADR 8. Supported Topologies The following sections discuss various topologies, both clustered and non-clustered, that can be employed. Combined web, application, and database server Combined web and application server with separate database server Single web server with combined application and database server Separate web, application, and database servers Adding additional web servers Adding additional application servers 9. Conclusion EEHAS minimize the risk of server down time and improve the productivity of the organization. Ecomm Technologies provides 24x7 customer onsite and remote support for EEHAS customers. Currently EEHAS solution is also available with TSM backup and recovery and enhancements with IBM monitoring tools like ITM, ITCAM and Performance Expert. EEHAS updates available in