Updated: Jul 28
Software-based logical replication for IBM i has been the mainstay for high availability and disaster recovery for many years, due to its ability to adapt to changing landscapes such as co-locations, and more recently the cloud. Maxava’s logical replication solution, Maxava HA, is based on remote journaling, an intrinsic part of the operating system with efficiency at its core, but what makes Maxava HA stand out from the competition?
Maxava HA has the capability to use before and after images, a feature provided by remote journaling which has credible benefit to the area of audits. The before image is used to check that a record is as it should be before it is updated to the after image. If a difference is detected between the before Image and what is on the TARGET server prior to update, corrective action is automatically initiated by requesting a partial audit of the file along with a check for any other bad records, fixing just the bad records found. This gives Maxava HA better real-time in-flight data consistency checking which in turn means that both SOURCE and TARGET are synchronized more than some other HA solutions, resulting in less resources being required to maintain synchronization. Maxava HA is conducting continual audit checking on an update-by-update basis, self-healing where possible while flagging exceptions which may require further investigation.
CPU Consumed on Production (SOURCE)
While some logical replication solutions are fully dependent upon the IBM i Audit Journal (QAUDJRN) as a foundation for high availability, Maxava have opted for a different approach. The primary use of QAUDJRN is auditing and relying on it for high availability can have an unwelcome impact on the SOURCE server’s resources. As an example, in busy environments the Audit Journal become a bottleneck, potentially causing a delay in transactions being processed and sent before being applied to the TARGET machine, leaving you potentially exposed. Maxava HA has no requirement for there to be any core jobs active on the SOURCE server reading QAUDJRN.
Maxava’s innovative command intercept method has been designed to remove much of the resource required to maintain high availability away from the SOURCE server with most of the processing taking place on the TARGET, away from the demands that running production environments bring. This approach relays activity in the order in which it occurs, meaning the TARGET system need only process the activity it is sent, without the need for any re-sequencing.
Maxava HA has been designed to have a small and efficient footprint and is suitable for the most demanding environments with the largest of transaction volumes. This efficiency has been achieved with the introduction of a library called MAXSYS which contains a copy of IBM commands necessary to perform dynamic replication. The MAXSYS library sits above QSYS in QSYSLIBL (System Library List). Each copied command has its CPP (Command Processing Program) changed to a Maxava version and is also tagged with an exit point program to initiate a Maxava HA function prior to the normal execution of the QSYS command of the same name. This Maxava HA action has no significance to applications and the QSYS command executes as normal. As such both object and data activity are captured and moved off the SOURCE server immediately and without the delays that pre-processing introduces. Because of these efficiencies Maxava HA has fewer reasons to audit and fix, which in turn reduces the overhead on the SOURCE system.
Price and Flexibility
The most popular pricing option throughout the industry is now subscription based and Maxava are a pioneer of this offering, having provided it for several years. Subscription-based pricing allows you to switch from a traditional capital expenditure model to an easier to digest monthly or annual operational number. Subscription pricing provides the opportunity for you to adapt and flex as your requirements ebb and flow.
Perpetual license and maintenance options are still available for those preferring this traditional approach to software ownership.
Maxava have a long-standing pedigree in working with both Managed Server Providers operating their own Power Cloud, and Public Cloud providers such as Skytap and IBM (Power Virtual Server). Our Migrate Live™ service supports customers when they need to upgrade their IBM i environment or migrate to a new system, either on-premise or to the Cloud, without downtime thereby ensuring data integrity. Maxava’s replication technologies are a quick and dependable way to enable data to be copied to a new system while keeping it synchronized in real-time.
The Cloud is also a popular option for those looking to move away from on-premise or co-location forms of disaster recovery while taking advantage of consumption-based pricing while eliminating the need to pay for hardware and software maintenance. Maxava HA provides fast and reliable real-time IBM i replication to the Cloud.
Maxava HA runs natively in the Cloud, from region to region or between Cloud providers.
Maxava offer 24 X 7 customer service and support having adopted a follow-the-sun model with fully qualified experienced personnel in North America, Europe, Asia Pacific, and Japan. This model enables Maxava to offer first class local support while reducing response times and delays when solving customer issues and queries.
This article is written by Ash Giddings, Product Manager at Maxava