Product Technical FAQs
Below is a list of commonly asked questions. Click on a question to reveal the answer. For questions not covered below, please contact Marathon at 888-682-1142 or send us an email.
How do the Marathon availability solutions work?
everRun FT and everRun HA are software solutions that enable essentially any two standard Windows servers to operate as a single, fully redundant Windows environment, protecting applications from costly downtime due to failures within the hardware, network, and data. The software creates a virtual Windows environment on top of the two physical servers (and their installed Windows operating environments) upon which your applications are installed and run. With everRun FT, the virtual layer enables the two servers to operate in “lockstep” – executing identical instruction paths at the exact same time to ensure the application never suffers downtime or loss of data due to a device or even complete server failure. With everRun HA , the virtual layer utilizes the redundancy of the two physical servers to eliminate downtime due to device and storage failures. Should the active device fail, everRun HA will immediately utilize the redundant device on the second server to continue processing application requests without interruption. A complete server failure will result in the immediate migration of the virtual Windows environment to the secondary server.
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What is the difference between everRun FT and everRun HA?
everRun HA is a High Availability solution that provides protection for any Windows applications from the effects of hardware and server failures. everRun HA is for those systems and applications that require an automatic and immediate recovery should a complete server fail. The applications typically have a Recovery Time Objective (RTO) of a few minutes or less.
everRun FT provides complete fault tolerance for any Windows application, preventing application interruptions regardless of the severity of the failure. Even a complete server failure has no impact on the application state. everRun FT is for those mission critical applications that can’t afford ANY downtime, as even a few minutes of downtime is costly and unacceptable. These systems and applications generally have an RTO of 0.
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What is a CoServer?
A CoServer, in Marathon terminology, is a physical server configured with a licensed version of Windows and with Marathon software and drivers installed. A pair of CoServers form the base upon which the Marathon software creates a virtual Windows environment.
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Where does the Virtual OS run?
With everRun FT , the virtual OS runs on each CoServer simultaneously and in lockstep to ensure both physical servers are completely synchronized, including CPU, memory, I/O, and disk. With everRun HA , the virtual OS runs on just one of the CoServers at any given time, however it has a fully mirrored copy on the other CoServer. Should the active CoServer suffer a complete failure, the virtual environment will immediately start on the standby server. With either product, the virtual OS appears as a single Windows environment to administrators and users.
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Is everRun like a cluster?
Clustering technologies accomplish increased availability by use of failover techniques in order to minimize downtime. everRun eliminates downtime by proactively addressing failures to not require a failover when components and systems fail. Rather, failed components are taken offline while applications continue to run using their redundant counterparts on the paired host.
In addition, everRun works with ANY
Windows-based application without modification, whereas clustering
technologies require some amount of application awareness of the
clustering technology. This typically will require either writing
scripts or rewriting the applications to conform to the cluster API
(Application Programming Interface).
Cluster deployments also require
significant design considerations with ongoing maintenance and
support to maintain high availability of applications. everRun works
“out of the box” and requires no special scripting or ongoing
maintenance to assure continuous availability.
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How many application licenses do I need to purchase?
Generally only a single application license is
required as only one instance is installed, managed, and exposed on the network
within the everRun configuration. However some software licensing models dictate
that two licenses are required regardless of this fact. You should refer to your
specific license agreements to determine the correct licensing requirements.
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Are Marathon products like a replication solution?
Marathon sells replication solutions; everRun DR and everRun CDP, as well as availability solutions as the address different requirements. Replication, or DR, solutions provide data redundancy by copying data to a remote location. Some offer a failover option to have a standby server assume processing for a failed production server.; These are generally asynchronous copy solutions and will inherently incur data loss in the event of a failover. Failover is generally only a redirection of the server identity. Depending on the particular environment, completing the failover could take more than a few minutes and require clients to be restarted. This is often, and recommended, to be a manually initiated process.
For more details on the differences
between availability and replication/recovery please refer to our
whitepaper Breaking through the Noise Around Application
Availability’ or contact Marathon or one of our resellers.
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What versions of Windows does everRun FT run on?
everRun FT has been qualified on Windows 2000 Server and Advanced Server and Windows Server 2003 Standard and Enterprise Editions.
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What versions of Windows does everRun HA run on?
everRun HA has been qualified on Windows Server 2003 Standard and Enterprise Editions with SP1.
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Does everRun FT or everRun HA run on Web Edition or Small Business Server?
Marathon products have not been qualified on either Web Edition or Small Business Server based on customer demands and market analysis. Marathon continuously monitors the market for changes in user trends and will qualify additional operating system editions as these trends dictate.
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What servers do Marathon solutions run on?
Marathon products have been designed and proven to be hardware agnostic, however Marathon recommends basic formal qualification testing be performed for non-qualified platforms being considered for use. We continue to qualify new platforms as they become available. To check on specific servers, please contact Marathon or a Marathon reseller.
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Where does my application run – in the virtual or CoServer level?
Applications in a Marathon environment run in a virtual OS environment to enable the availability provided by everRun. The application is installed and managed in only one place, the virtual environment, which provides for very simple deployment and management. It’s the same as if the application were installed on a single standalone server, yet it is protectedagainst device and hardware failures. The Marathon software handles all of the underlying logic for providing redundancy and availability without any changes to the application.
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Can I run Windows applications at the CoServer level?
It is possible to run additional applications on the physical CoServer however this is not a recommended configuration.
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Do the Windows versions have to be identical in all 3 environments?
No. Running Standard Edition on the CoServers and Enterprise Edition on the Virtual, is a common practice. It is recommended that OS updates and service packs are.
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How do Marathon products protect my network connections?
Both everRun FT and everRun HAprotect network connectivity by creating a single ‘virtual’ NIC from two physical NIC’s; one from each CoServer. In essence, the two network cards share a MAC address, and Marathon provides a single network connection and IP address to applications. Should one physical NIC fail, the application will continue processing without interruption utilizing the other physical NIC.
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How do Marathon products accomplish disk mirroring?
everRun guarantees data and transactional integrity by performing simultaneous writes to each CoServer, ensuring each is committed before giving acknowledgement back to the application. These writes are done at the same time to prevent performance impact to the application.
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Do the two servers have to be exactly identical?
With everRun FT , in order to operate in lockstep, both CoServers need to be identical with respect to CPU and memory configurations. Network adapters do not need to be identical but need to operate at the same speed. Storage configurations do not need to be identical; however mirroring disks of different sizes will result in a virtual disk limited by the smaller of the two disks. everRun HA allows for different hardware configurations within each CoServer.
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Does Marathon support SAN and NAS storage configurations?
While not requiring any specific shared storage architecture, Marathon products provide general SAN and NAS support as part of the base product. To assure a successful implementation, Marathon recommends formal qualification with any SAN or NAS architecture not already qualified by Marathon.
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What is involved in migrating our existing applications to a Marathon environment?
The servers to be used for the Marathon environment will need to be configured with just a base Windows OS installed. The Marathon software is then installed on top of these environments to create the virtual Windows environment, on which applications can then be installed. For existing servers, Marathon and its partners can work with you to develop a migration plan that assures minimal impact to users.
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How does Marathon qualify Windows security patches?
Because of their critical nature, we screen and test Microsoft Security Updates that apply to Windows 2003 and are posted on Microsoft’s automatic update website area. In the majority of cases, Windows security updates are fully compatible with Marathon products. In the rare cases where an issue is found, we post an advisory on our support website knowledgebase and provide an update to resolve the issue.
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How does everRun provide Disaster Tolerance?
The everRun SplitSite option provides the ability to separate the two everRun CoServers geographically to provide protection against site and regional failures.
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How far can a SplitSite configuration span?
The distance limitations of SplitSite are dependent on the network connections between the two CoServers. SplitSite requires a 10ms or less round trip latency between CoServers.
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