Shield Goes Lean and Mean with HA Software
May 20, 2015 Alex Woodie
Shield Advanced Solutions is shipping a new release of its IBM i high availability software that weighs significantly less than previous releases, and should consume fewer resources as well, thereby boosting performance. The HA audit and role swap processes were also enhanced with HA4i version 7.2, and the user interface also saw some improvements.
IBM remote journaling, which forms the basis for the majority of HA products on the market, is a fantastic technology, as it moves the replication of database files underneath the operating system layer, and in the process makes it nearly foolproof to use. But the flipside of that ease-of-use is a performance hit and increased latency, as large amounts of data are automatically sent across the wire.
When remote journaling first started to be used for HA more than 15 years ago, it brought with it a performance hit in excess of 10 percent on the production server, keeping in mind that most of the performance hit takes place on the secondary machine with remote journaling. Over the years, that performance hit on the production system has come down to the five percent range, which is the baseline, if you will, for high availability software vendors who build their applications atop IBM’s remote journaling technology.
Shield president Chris Hird says packaging improvements in HA4i 7.2 should provide a performance boost. “Just the way we package the product has changed–we now have service programs instead of binding modules at compile time)–so the footprint of the product is far smaller and meaner in terms of memory and CPU requirements,” he says. “It is now only 9 MB to install, where a PTF would be 130 MB-plus in the old method.”
HA4i, which is entering its eighth year in the market, has grown over the years to include many enterprise-level HA features, and perhaps was ready for a little belt-tightening.
“Performance has always been important,” Hird says, “[but] we have tightened up some of the code as part of the new packaging model and removed some features that caused slowdowns under some circumstances. This has removed a lot of overhead simply by making the programs smaller so paging in and out and memory management is lower. We are always striving for optimal performance, so code is constantly reviewed to see if we can be more efficient. New APIs from IBM bring a lot of that to the table.”
While the overhead has been reduced, Hird still managed to add useful new features that should help IBM i shops maintain the role-swap readiness that is so critical in production HA environments. The new features are in the areas of:
Auditing: Detecting out-of-synch files and objects is a critical element in any HA environment, and Shield has added a number of new audit processes to make that easier. For starters, it’s created a new audit mapping process that will enable HA4i to track the objects being audited, including knowing what objects were audited and what command was used to audit it.
According to Hird, this brings the additional benefit of allowing the product to manage the audits of very large libraries across multiple days. Because audits must be carried out when the objects are not being accessed, it imposes strict time windows on audits. With HA4i’s new auditing process, Shield is allowing users to conduct the audit in a piecemeal manner, thereby making it more convenient for the customer to conduct the audits.
Role Swap: The all-important role-swap process is where the rubber meets the road for HA products, and Shield has bolstered this process with version 7.2. According to Hird, the enhancements are all about enabling more automated data collection and more detailed configurations.
“Before, when a role swap was carried out, we expected the users to carry out some configuration of the start points,” he says. “We now set up start points and get the users to confirm that we have selected the correct ones. This is nearly always right, as we manage the journals as part of the role swap, but it does give the user the ability to change if required.” HA4i also automatically cleans up and resets certain statuses that previously had to be done manually, thereby making the role-swaps faster and better.
User Interface: The HA4i UI has also gone on a diet, as Shield has removed some clutter from the screen and improved the context-sensitive help. “We have also added new monitoring options on the target that allow source status to be collected and displayed,” Hird says. “The PHP interface also went through an overhaul to provide some new monitoring and management features.”
Hird says the new features and enhancements have taken the product beyond its original concepts, while still retaining the easy to manage philosophy. He dubs it “Big HA for SMBs,” referring to the small and medium-sized businesses that are Shield’s bread and butter with the HA4i product.
“Big HA for SMBs is really about providing an enterprise-level solution for the SMB market,” he says. “It uses the same technology that you would expect from an enterprise-level solution, but in an SMB package. It’s simple to install, configure and manage without the complexity you get from an enterprise-level product.”
For more info, see the company’s website at www.shieldadvanced.com.