Shared nothing cluster vs shared disk cluster

• 

  Video Surveillance (CCTV) [+]

  In video surveillance systems, Evidian SafeKit implements high availability with synchronous replication and failover of

  • Milestone XProtect,
  • Samsung Security Manager (SSM),
  • Siemens CCTV Video Surveillance

  Use case: In South Korea, WithNCompany deploys high availability of the Samsung Video Surveillance platform with SafeKit.

  
  
• 

  TV broadcasting [+]

  Harmonic is using SafeKit as a software OEM high availability solution and deploys it with its TV broadcasting solutions over satellites, terrestrials, cable, IPTV. Over 80 SafeKit clusters are deployed on Windows for replication of Harmonic database and automatic failover of the critical application. Philippe Vidal, Product Manager, Harmonic says: “SafeKit is the ideal application clustering solution for a software publisher looking for a simple and economical high availability software. We are deploying SafeKit worldwide and we currently have more than 80 SafeKit clusters on Windows with our critical TV broadcasting application through terrestrial, satellite, cable and IP-TV. SafeKit implements the continuous and real-time replication of our database as well as the automatic failover of our application for software and hardware failures. Without modifying our application, it was possible for us to customize the installation of SafeKit. Since then, the time of preparation and implementation has been significantly reduced.”

  
  
• 

  Finance [+]

  The European Society of Warranties and Guarantees in Natixis uses SafeKit as a high availability solution for its applications.

  Over 30 SafeKit clusters are deployed on AIX and Windows in Natixis.

  
  
• 

  Industry [+]

  The Sydel software editor implements high availability of its ERP with SafeKit and deploys the solution in the food industry.

  Over 20 SafeKit clusters are deployed on Linux and AIX with Oracle.

  
  
• 

  Air traffic control [+]

  Air traffic control systems supplier, Copperchase, deploys SafeKit high availability in airports.

  Over 20 SafeKit clusters are deployed on Windows.

  Tony Myers, Director of Business Development says:

  “By developing applications for air traffic control, Copperchase is in one of the most critical business activities. We absolutely need our applications to be available all the time. We have found with SafeKit a simple and complete clustering solution for our needs. This software combines in a single product load balancing, real time data replication with no data loss and automatic failover. This is why, Copperchase deploys SafeKit for air traffic control in airports in the UK and the 30 countries where we are present.”

  
  
• 

  Bank [+]

  Software vendor Wellington IT deploys SafeKit high availability with its banking application for Credit Unions in Ireland and UK.

  Over 25 SafeKit clusters are deployed on Linux with Oracle.

  Peter Knight, Sales Manager says:

  “Business continuity and disaster recovery are a major concern for our Locus banking application deployed in numerous Credit Unions around Ireland and the UK. We have found with SafeKit a simple and robust solution for high availability and synchronous replication between two servers with no data loss. With this software solution, we are not dependent on a specific and costly hardware clustering solution. It is a perfect tool to provide a software high availability option to an application of a software vendor.”

  
  
• 

  Transport [+]

  Paris transport company (RATP) chose the SafeKit high availability and load balancing solution for the centralized control room of line 1 of the Paris subway.

  20 SafeKit clusters are deployed on Windows and Linux.

  Stéphane Guilmin, RATP, Project manager says:

  “Automation of line 1 of the Paris subway is a major project for RATP, requiring a centralized command room (CCR) designed to resist IT failures. With SafeKit, we have three distinct advantages to meet this need. Firstly, SafeKit is a purely software solution that does not demand the use of shared disks on a SAN and network boxes for load balancing. It is very simple to separate our servers into separate machine rooms. Moreover, this clustering solution is homogeneous for our Windows and Unix platforms. SafeKit provides the three functions that we needed: load balancing between servers, automatic failover after an incident and real time data replication.”

  And also, Philippe Marsol,  Atos BU Transport, Integration Manager says:

  “SafeKit is a simple and powerful product for application high availability. We have integrated SafeKit in our critical projects like the supervision of Paris metro Line 4 (the control room) or Marseille Line 1 and Line 2 (the operations center). Thanks to the simplicity of the product, we gained time for the integration and validation of the solution and we had also quick answers to our questions with a responsive Evidian team.”

  
  
• 

  Healthcare [+]

  The software integrator Systel deploys SafeKit high-availability solution in firefighter and emergency medical call centers.

  Over 30 SafeKit clusters are deployed on Windows with SQL Server.

  Marc Pellas, CEO says:

  “SafeKit perfectly meets the needs of a software vendor. Its main advantage is that it brings in high availability through a software option that is added to our own multi-platform software suite. This way, we are not dependent on a specific and costly hardware clustering solution that is not only difficult to install and maintain, but also differs according to client environments. With SafeKit, our firefighter call centers are run with an integrated software clustering solution, which is the same for all our customers, is user friendly and for which we master the installation up to after-sales support.”

  
  
• 

  Government [+]

  ERP high availability and load balancing of the French army (DGA) are made with SafeKit.

  14 SafeKit clusters are deployed on Windows and Linux.

  Alexandre Barth, Systems administrator says:

  “Our production team implemented the SafeKit solution without any difficulty on 14 Windows and Linux clusters. Our critical activity is thus secure, with high-availability and load balancing functions. The advantages of this product are easy deployment and administration of clusters, on the one hand, and uniformity of the solution in the face of heterogeneous operating systems, on the other hand.”

   

  
  

• Low Complexity
• Plug&Play deployment with no specific skills
• Suitable for large deployments in many sites (very simple to deploy)
• 2 nodes (3 nodes replication possibility)
• No shared storage requirement
• No Domain Controller requirement
• Same solution on Windows and Linux
• Support Windows Server and Client editions
• Well documented API and support
• Synchronous data replication (no data loss in case of failure)
• Replicated directories can be in the system disk
• Supports multiple heartbeats and vitual IP addresses
• Offers configurable software, hardware and network checkers
• For the quorum, does not require a special disk or a third machine or a dedicated link between both servers
• Automatic failover of services with a recovery time in the order of one minute
• Automatic failback when a server comes back after a failure (no manual operation)
• A very simple console to deploy the solution and to maintain it afterwards for end-customer
• Supports human errors (40% of causes of unavailability) thanks to its simplicity
• Supports software failures (40% of causes of unavailability): regression on software update (version N and N+1 can coexist), Operating System frozen, software bug
• Supports hardware and environment failures (20% of causes of unavailability), including the complete failure of a computer room with 2 nodes in two remote sites

RTO is the time during which the application is unavailable in case of failure. RTO of the SafeKit mirror solution is in the order of 1 mn.

For a hardware failure, RTO = heartbeat timeout (default 30 s, can be changed in userconfig.xml) + time to restart services.

For a software failure or an administrator restart, RTO = time to (cleanly) stop services + time to restart them.

Be careful, with solutions that reboot a full virtual machine in case of failure, the RTO is unpredictable as manual operations may be required after a hardware crash to reboot the virtual machine.

RPO reflects the data loss in case of failure. RPO of the SafeKit mirror solution is 0 as the replication is synchronous and real-time.

Be careful, with asynchronous replication, RPO is not 0 and there is data loss in case of failure when the application restarts on the secondary server.

• Low Complexity
• Plug&Play deployment with no specific skills
• Suitable for large deployments in many sites (very simple to deploy)
• 2 nodes or more
• No network load balancers requirement
• No proxy server requirement (above the farm cluster)
• No Domain Controller requirement
• No restriction in VMware due to multicast or unicast address
• Same solution on Windows and Linux
• Support Windows Server and Client editions
• Well documented API and support
• Supports multiple monitoring channels on multiple networks for server failure detection
• Supports multiple vitual IP addresses
• Offers configurable software, hardware and network checkers
• Offers the mirror cluster with synchronous real-time replication and failover
• Automatic failover with a recovery time in the order of a few seconds
• Automatic failback when a server comes back after a failure (no manual operation)
• A very simple console to deploy the solution and to maintain it afterwards for end-customer
• Supports human errors (40% of causes of unavailability) thanks to its simplicity
• Supports software failures (40% of causes of unavailability): regression on software update (version N and N+1 can coexist), Operating System frozen, software bug
• Supports hardware and environment failures (20% of causes of unavailability), including the complete failure of a computer room with 2 nodes in two remote sites

RTO is the time during which the application is unavailable in case of failure. RTO of the SafeKit farm solution is in the order of a few seconds on hardware failure.

For a hardware failure, RTO = failure detection timeout through monitoring channels (default a few seconds): after the timeout the load balancing filters are reconfigured.

For a software failure or an administrator restart, RTO = time to (cleanly) stop services + time to restart them.