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HP Serviceguard Solutions for Linux

Guest blog written by Ravichandra Krishnamurthy, HP Serviceguard Technical Architect

 

The HP Serviceguard for Linux (SG/LX) solution ensures high availability of enterprise workloads. It monitors many aspects of cluster health including health of network paths, storage connectivity, volume monitoring, and data replication status.

 

SG/LX is a cluster implemented at the user-level which shares most of its implementation with Serviceguard for HP-UX. Serviceguard for HP-UX has been in the market for over 20 years and is well known as the best in the industry for its availability, robustness and prevention measures against data corruption.

 

SG/LX comes with many existing and new features, of which some of the newer ones are described here.

Availability

  • Live Application Detach (LAD): enables administrators to perform HB network maintenance or maintenance on one or more nodes of the cluster or the entire cluster when the workloads are online.
  • Maintenance can be easily performed by two of the maintenance modes
    1. Partial startup maintenance mode helps in performing maintenance on a single resource while the workload is partially started by bringing up some resources so as to allow easy maintenance on one of the other resources.
    2. Placing a running workload into maintenance mode so that network or a few other resources can be examined and maintenance performed on them without the workload having to failover to another node
  • Online workload reconfiguration: helps administrators add, modify or delete resources from a running workload without having to bring them down at all
  • Rolling Upgrade: helps users to migrate from one version of SG/LX to the next, as well as upgrade the current version with a patch, in a rolling fashion, while keeping all the workloads running on other nodes of the cluster.

Robustness

  • Various server and disk based Quorum methods are available as arbitration mechanisms, to handle network partitions, when they occur. These arbitrators uniquely elect one of the partitions and ensure that all workloads in the cluster are moved to this partition after ensuring I/O quiescence from the other partition is complete.
  • Deadman kernel driver (a mechanism used by SG/LX) ensures that a node which loses its membership in a cluster, due to network partition or any other reason, is rebooted within a certain duration.

Prevention measures against data corruption

  • SCSI-3 Persistent Reservation is used by SG/LX to ensure that only the node that is running the workload is allowed to perform write I/Os to its shared storage disks. As part of cluster reconfiguration, SG/LX includes I/O quiescence stage. This stage comes right after the stage where deadman driver has ensured that nodes who lost membership, have been rebooted and allows time for disk I/O from evicted nodes to complete.

 Handling workload dependencies

  • SG/LX provides multiple ways to specify the dependencies between workloads, providing a rich set of dependency description directives that helps administrators to easily configure and handle dependencies between workloads.

Health and connectivity monitoring

  • SG/LX comes with a wide array of monitoring capabilities, which includes network layer 2 and layer 3 monitoring, storage connectivity monitoring as well as host-based data replication status monitoring, and the capability to affect failover based on this.

 

SG/LX supports many mechanisms for building in redundancies in its configuration, including that of multiple paths for Heartbeat and data network using Linux network bonding, and multiple paths to storage using multipath. In its disaster recovery products like, Extended Distance cluster, Metrocluster and Continentalclusters, it uses multiple switches, routers and FC switches, configured and connected in redundant ways to build in redundancy in the various paths between the sites.

 

It also supports Linux distributions like RHEL and SLES on x86 platforms. Virtualization technologies like VMWare and KVM are supported, allowing administrators a choice of combinations of physical servers and virtual guests in a cluster. This helps to reduce IT costs by using virtual guests for standby nodes or recovery sites, in case of active-standby configurations. SG/LX supports customized toolkits for providing HA for well-known applications like SAP, SAP Sybase ASE and Sybase Replication Server, Oracle, NFS, and Enterprise DB PPAS. Well known configurations of these applications are supported as part of these customized HA toolkits.

 

HP Serviceguard for Linux provides a comprehensive set of solutions ensuring high availability and disaster recovery for the mission critical needs of enterprise workloads. I will write more about of the unique capabilities of this solution in the coming weeks.

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HP Servers, Converged Infrastructure, Converged Systems and ExpertOne
About the Author(s)
  • I work as a Master Architect in HP Servers R & D group. I work with teams spread across the lab and outside to build solutions which are highly available on HP-UX, OpenVMS and Mission Critical Linux platforms. In particular I contribute to develop HP Serviceguard clusters, HP-UX Security and Middleware products. I have been with HP for last 17 years and have exposure to HA/DR field from both R & D and customer perspectives.
  • Kirk Bresniker is the Vice President/Chief Technologist for HP Business Critical Systems where he has technical responsibility for all things Mission Critical, including HP-UX, NonStop and scalable x86 platforms. He joined HP in 1989 after graduating from Santa Clara University and has been an HP Fellow since 2008.
  • I’m the worldwide marketing manager for HP NonStop. I’ll be blogging and tweeting out news as it relates to NonStop solutions – you can find me here and on twitter at @CarolynatHP
  • Cynthia is part of the HP ExpertOne team. ExpertOne offers professional IT training and certifications from infrastructure refresh to areas that span across the datacenter like Cloud and Converged Infrastructure.
  • Hi, I work on the HP Servers team as HP-UX worldwide product marketing manager. I´m interested in how customers use our technology and will be blogging about their stories and on how our products evolve to help their businesses be always on.
  • I have worked with NonStop systems since 1982. I am a Master Technologist for HP and am part of the IT SWAT organization, the Cloud SWAT and work with HP Labs. I report into the Enterprise Solutions and Architecture organization.
  • Joe Androlowicz is a Technical Communications and Marketing manager in HP’s NonStop Product Division. Joe is a 25 year journeyman in information systems design, instructional technologies and multimedia development. He left Apple Computer for Tandem Computers to help launch G03 and hasn’t looked back yet. He previously managed the program management team for the NonStop Education and Training Center and drove the development and growth of the NonStop Certification programs.
  • Hello! I am a social media manager for servers, so my posts will be geared towards HP server-related news & info.
  • HP Servers, Converged Infrastructure, Converged Systems and ExpertOne
  • Luke Oda is a member of the HP's BCS Marketing team. With a primary focus on marketing programs that support HP's BCS portfolio. His interests include all things mission-critical and the continuing innovation that HP demonstrates across the globe.
  • I am the Superdome 2 Product Manager. My interest is to learn how mission critical platform helps customers and would also like to share my thoughts on how Superdome has been helping customers and will continue to do so.
  • I work in the HP Servers marketing group, managing a marketing team responsible for marketing solutions for enterprise customers who run mission-critical workloads and depend on HP to keep their business continuously running.
  • Mohan Parthasarathy is a Technical Architect in the HP-UX lab. His primary focus currently is in the core kernel, platform enablement and virtualization areas of HP-UX. Mohan has worked on various modules of HP-UX, including networking protocol stacks, drivers, core kernel and virtualization
  • I’m the Worldwide Product Marketing Manager for HP Serviceguard Solutions for Linux in BCS. I’ll be blogging about the latest news and enhancements as it relates to this product.
  • Greetings! I am on the HP Enterprise Group marketing team. Topics I am interested in include Converged Infrastructure, Converged Systems and Management, and HP BladeSystem.
  • As a Managing Consultant for HP’s Enterprise Solution & Architecture group, I collaborate with client business and IT senior management to understand, prioritize and architect advanced use of data and information, drawing insights required to make informed business decisions. My current focus leverages event-driven business intelligence design techniques and technologies to identify patterns, anticipate outcomes and proactively optimize business response creating a differentiated position in the marketplace for the client.
  • Wendy Bartlett is a Distinguished Technologist in HP’s NonStop Enterprise Division, and focuses on dependability – security and availability - for the NonStop server line. She joined Tandem in 1978. Her other main area of interest is system architecture evolution. She has an M.S. degree in computer science from Stanford University.
  • I am part of the integrated marketing team focused on HP Moonshot System and HP Scale-up x86 and Mission-critical solutions.


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