Wasser drauf, umrühren, fertig?

Transcription

1 <Insert Picture Here> Wasser drauf, umrühren, fertig? Steffen Miller Principal Sales Consultant

2 Agenda Motivation Was ist ein WebLogic Cluster? Cluster Konzepte Q & A

3 WLS HA Focus Areas Data Failure Human Error WLS with Oracle RAC Site Disaster Software Failure WAN Clusters for Disaster Recovery UNPLANNED DOWNTIME Failures & Solutions Clusters Service Migration Hardware Failure Clusters Server & Service Migration Clusterware integration

4 WLS HA Focus Areas Application Upgrades Hot redeployment Side By Side Deployment PLANNED DOWNTIME Operations & Solutions Configuration Changes Server Upgrades Dynamic changes Rolling cluster upgrade

5 Agenda Motivation Was ist ein WebLogic Cluster? Cluster Konzepte Q & A

6 What is WebLogic Cluster? Domain A Cluster Cluster Servlet/JSP Clusters Cluster EJB/RMI Object Clusters

7 Agenda Motivation Was ist ein WebLogic Cluster? Cluster Konzepte Q & A

8 Concepts for WLS HA-itilities Cluster communication IP Multicast/Unicast IP Sockets Web Cluster Proxy plug-in External load balancer Sync/Async session replication EJB/RMI clustering Replica-aware stub Multiple LB algorithms ActiveCache Session Rep. MAN/WAN replication Whole Server Migration Automatic Service Meet SLAs Migration Develop Secure Hot Redeployment Manage Integrate Side-by-side deployment Configure, Deploy Dynamic config changes Rolling upgrade WLS with Oracle RAC

9 Key Benefits of Clustering Scalability Load Balance Even distribution of jobs Multiple copies of an object that can do a particular job must be available High-Availability Failover When a object processing a job becomes unavailable, a copy of the object elsewhere takes over and finishes the job

10 Web Cluster (JSPs and Servlets) Replication: HTTP session state of clients Primary replicates session to Secondary (both Sync and Async) Replication: Failover Initiated by load balancer after encountering an error Secondary becomes the new Primary and chooses a Secondary Load Balance New client sessions are load balanced Must maintain session affinity or sticky load balance Types of load balancers Proxy plug-in running within a iplanet, Apache or IIS HttpClusterServlet running within another WLS External load balancer, e.g. BigIP/F5, Alteon/Nortel,Cisco Load balancing algorithms: Round robin

11 Web Cluster WebServer with proxy plug-in Cluster WebServer WLS instance Proxy plugin WLS instance WebServer Proxy plugin WLS instance iplanet/sunone Apache IIS WLS with HttpCLusterServlet

12 Session State Replication LAN replication Availability via synchronous or asynchronous, inmemory replication between primary and secondary #1 #2 A B A CB Browser Web Servers B C Servlet Engines

13 EJB/RMI Object Cluster EJB invocations Stateless Session EJB Invocations are load balanced to all members where the EJB is deployed ( replicas ). Stateful Session EJB If not clustered, they are pinned to the member where created If clustered, the state is replicated (to a secondary server instance) and the replica aware stub is aware of locations (primary and secondary).

14 Metro-Area Network Replication Local LB Cluster A Global LB Local LB Cluster B

15 Disaster Recovery - Site Replication Wide-Area Network Replication Local LB Cluster A DB-1 Global LB Async replication Local LB Cluster B DB-2

16 Whole server migration WebLogic Cluster Services Typically deployed homogeneously, enabling transparent fail over Pinned services" such as JMS and JTA are targeted to individual servers, requiring migration Before WLS 9.0, migration was manual Unless using an expensive third-party solution (Veritas, Sun Cluster,...) Service Level Migration of services was a manual process High Availability targets such as 5 9's % 5.26 minutes downtime per year Is there an automated process for migration of pinned services?

17 The server with the earliest start time becomes the cluster master Failure Scenario with Whole Server Migration/Consensus Leasing Node managers start the servers in the cluster All hosts compete to get the lease to run Server 4. The cluster master grants the lease to this server and calls the node manager to start the server. Server 1 Server 2 Server 4 NM NM Servers send heartbeats to the cluster master to renew their leases, and the cluster master sends lease table data to other servers in the cluster. NM Server 3 Server 4 NM This host fails and then loses its lease to run Server 4.

18 Service Migration Applies to services that run as singletons in a cluster: JMS servers, their hosted destinations, and related services JTA transaction recovery service for a server User-defined singleton services Enables you to restart these services on another running server in the cluster: For JMS, rescue stranded persistent messages For JTA, process incomplete transactions for a failed server For user-defined singleton services, guarantees that the process runs exactly once in the cluster (WLS automatically restarts it somewhere in the cluster)

19 How automatic JMS migration works Servers in a cluster compete to be the cluster leader. The cluster leader grants leases to servers to host migratable targets JMS Server 3 Queue3_1 Queue3_2 FileStore3 JMS Server 2 Queue2_1 Queue2_2 FileStore2 JMS Server 4 Queue4_1 Queue4_2 FileStore4 JMS Server 1 Other servers poll the Queue1_1 lease master and compete for the lease Queue1_2 to host a migratable target. The lease master FileStore1 grants a When lease a to server the most becomes unhealthy appropriate or fails, host. it loses it s lease to host the It migratable all starts with target. Migratable Targets groups of deployed objects that migrate together as a unit

20 Production Redeployment Side by Side Deployment Multiple application versions can coexist New client requests are routed to active version; Existing client requests can finish up with existing version Automatic Retirement Policy: Graceful, Timeout Test application version before opening up for business Rollback to previous application version Two versions of the application can be active at any given point of time

21 WebLogic Server Dynamic Updates Batch Updates User obtains a configuration lock Makes multiple config changes and deployments Activates or rolls back changes Previous configurations archived Configuration Deployment Configuration changes deployed to managed servers Managed servers listen for dynamic settings Static settings reflected on server restart Dynamic configuration settings Take effect when changes activated Approximately 1,400 dynamic configuration settings Supports common tunables, channels, scalability, performance settings

22 WLS Rolling Upgrade Upgrades a running cluster with a patch, maintenance pack, or minor release without shutting down the entire cluster. During the rolling upgrade of a cluster, each server in the cluster is individually upgraded and restarted while the other servers in the cluster continue to host your application. You can also uninstall a patch, maintenance pack, or minor release in a rolling fashion.

23 WLS Clusters Customer deployments Typical configuration is 2,4 or 8 node cluster across 2 or 4 machines with a max of 8-32 nodes per cluster. We recommend splitting large session objects (e.g. 10 mbyte) into smaller sessions across multiple JVMs as opposed to a larger session in one JVM Replicating the session data across 2 JVMs reduces the memory utilization More efficient to have 2 JVMs with 1 Gig vs. running on a JVM with 2 Gig. Not just garbage collection but work scheduling, paging etc. makes the 2 JVMs attractive.

24