Custom Non-LDAP External Accounts Integration

7. Cluster Configuration

This chapter contains general notes about the synchronized configuration of an Oracle Service Registry cluster and gives instructions on how to deploy Oracle Service Registry to a WebLogic Cluster Section 7.4, WebLogic specific configuration for use with cluster .

7.1. Cluster operation

Cluster operation is achieved by running multiple registries and joining their functionality with a load balancer proxy. Load balancing is used to distribute requests among registries to get the optimal load distribution. The load balancer should be configured to distribute requests among all physical endpoints of the registry nodes. If using an application server, refer to its documentation for details about configuring load balancing. Figure 45. Oracle Service Registry in WebLogic Cluster Clients to Oracle Service Registry access TCP ports on the balancer which forwards the connection to a running cluster node with an actual Oracle Service Registry. Each Oracle Service Registry has a connection to a common database so that each Oracle Service Registry has access to the latest data. This connection also serves as a distribution point for changed configurations and inter-node events. When an Oracle Service Registry node fails there are various reasons for this such as hardware problems, network connection problems or software failure, other nodes can work without it. The intelligent load balancer will detect this and further requests will not be directed there until the node starts to respond. Every node has a Node ID - a string identifying the node. Each node should have a different ID. Breaking this rule will cause nodes with the same ID to miss some configuration changes and synchronization events. Node ID can be specified by the administrator in the REGISTRY_HOME\app\uddi\conf\nodeid.xml file. If it is not specified before the initial start of Oracle Service Registry, it will be generated as a unique UUID string. It is possible to change it later, but node-local configurations under the old ID will be left in the database. Ensure that EARWAR file generated for deployment has either: 1. Empty Node ID - so that each deployment of the file will generate a unique Node ID on first run and will retain it until deletion or redeployment of the EARWAR file. You can use the EARWAR file to deploy on all nodes. 2. Specified Node ID - when you deploy the EARWAR file to a single node and generate another EARWAR file for others. You can choose meaningful names for Node ID this way. You can set the Node ID in the nodeid.xml file before starting setup to generate EARWAR file. If you use generation of EARWAR file directly from installer the Node ID will be empty. Page 124

7.1. Cluster operation

Note Latest configurations are identified by internal index sequencing. Time stamps of configurations as displayed in configuration management UI are not relevant as they may be unreliable in case of clock skew on a cluster node. Cluster operation is affected by the interaction of connection security HTTPS and the load balancer. For security reasons, client access is done using the HTTPS protocol. This protocol requires that there is a valid and matching security certificate on the server side possibly on the client side too if client authentication is required. There are generally two methods for achieving clustered operation via independent load balancer. If you deploy on an application server it may provide an integrated load balancer for you which may be easier to configure than an independent load balancer. 1. Secure connection can take a place between a client and the load balancer. The load balacner is the end point for the secure connection which originated at the client. The load balancer will make an independent connection to some of the Oracle Service Registry nodes. This connection may be either in HTTP or HTTPS. The certificate which the client checks has to be placed on the load balancer. A connection between the load balancer and each Oracle Service Registry can be protected by HTTPS in which case the load balancer and the registries should know each others certificates. Figure 46. Security in cluster, method 1. 2. Secure connection can be passed by the load balancer and terminated at the cluster node. This case requires that the certificates on all the nodes be the same to provide the illusion of a single service. However the common name inside the certificate should specify the DNS name of the balancer. Page 125

7.1. Cluster operation