OpenVMS Cluster Connection Manager and the Quorum Scheme

1. OpenVMS Cluster Connection Manager and the Quorum Scheme Keith Parris Systems/Software Engineer Multivendor Systems Engineering Global Solutions Engineering HP Services Welcome. My name is Keith Parris. By now you�ve probably seen the presentation entitled �Cluster Technology Overview and OpenVMS Cluster Summary.� Today we�re going to take a deeper look at the Theory of Operations of OpenVMS clusters.Welcome. My name is Keith Parris. By now you�ve probably seen the presentation entitled �Cluster Technology Overview and OpenVMS Cluster Summary.� Today we�re going to take a deeper look at the Theory of Operations of OpenVMS clusters.

2. page 2 June 23, 2012 Preview The Connection Manager protects against partitioned clusters (a.k.a. Split-Brain Syndrome) First, let�s review some of the basic capabilities of OpenVMS Clusters: The Quorum Scheme prevents subsets of the cluster from accessing shared resources like disks and file systems in an uncoordinated manner Access to these shared resources is orchestrated with the help of the Distributed Lock Manager OpenVMS has a Cluster-wide File System And although it may contain many separate server or workstation nodes, there is a common security environment, and it can be managed as a whole Looking in from the outside, it looks and behaves like a single system, and To the users or applications running within the cluster, it doesn�t make any difference which node they�re running on, because it all looks the sameFirst, let�s review some of the basic capabilities of OpenVMS Clusters: The Quorum Scheme prevents subsets of the cluster from accessing shared resources like disks and file systems in an uncoordinated manner Access to these shared resources is orchestrated with the help of the Distributed Lock Manager OpenVMS has a Cluster-wide File System And although it may contain many separate server or workstation nodes, there is a common security environment, and it can be managed as a whole Looking in from the outside, it looks and behaves like a single system, and To the users or applications running within the cluster, it doesn�t make any difference which node they�re running on, because it all looks the same

3. page 3 June 23, 2012 Overview of Topics System Communication Architecture (SCA) and its guarantees Interconnects Connection Manager Rule of Total Connectivity Quorum Scheme Failure detection mechanisms Failure ride-through State transitions This is an overview of what we�ll be talking about today: First, we�ll look at the System Communications Architecture and what it provides Next, we�ll look at the Connection Manager, with its Rule of Total Connectivity and Quorum Scheme After that, we�ll look at the OpenVMS Distributed Lock Manager We�ll look briefly at the Cluster Server Process and what it does Next, we�ll look at how the Mass Storage Control Protocol servers work for disks and tapes And finally, we�ll look at how OpenVMS provides support for redundant hardware.This is an overview of what we�ll be talking about today: First, we�ll look at the System Communications Architecture and what it provides Next, we�ll look at the Connection Manager, with its Rule of Total Connectivity and Quorum Scheme After that, we�ll look at the OpenVMS Distributed Lock Manager We�ll look briefly at the Cluster Server Process and what it does Next, we�ll look at how the Mass Storage Control Protocol servers work for disks and tapes And finally, we�ll look at how OpenVMS provides support for redundant hardware.

4. page 4 June 23, 2012 OpenVMS Cluster Overview An OpenVMS Cluster is a set of distributed systems which cooperate Cooperation requires coordination, which requires communication An OpenVMS Cluster consists of a set of servers and/or workstations that are connected together and which work together in a cooperative fashion. In order to cooperate, they must talk with one another.An OpenVMS Cluster consists of a set of servers and/or workstations that are connected together and which work together in a cooperative fashion. In order to cooperate, they must talk with one another.

5. page 5 June 23, 2012 Foundation for Shared Access