DataMirror's iCluster 2.1 Offers Full Mirroring of iASPs
by Alex Woodie
To simplify storing data for different areas of their business, iSeries shops are increasingly turning to independent auxiliary storage pools, several sources have said. In support of this trend, DataMirror recently started shipping a new release of its OS/400 clustering application, iCluster Version 2.1, which offers full support for mirroring of iASPs, as well as improved monitoring and autonomic functions.
The iCluster is DataMirror's flagship high availability offering for iSeries shops. While the company also offers its older High Availability suite, the iCluster product, which is based on OS/400 cluster services and its integrated heartbeat monitoring and automated failovers, now accounts for the majority of DataMirror's high availability sales, with hundreds of companies using iCluster, says Glen Sakuth, senior director of development for Toronto-based DataMirror.
"This is a very large release for us," Sakuth says of iCluster 2.1, the first major release of the product in more than a year. "It improves the customer experience significantly, as well as gives the capabilities to utilize iASPs more effectively."
Previously, iCluster did not offer full support for OS/400 objects in iASPs. With this release, DataMirror has delivered fully integrated support for iASP mirroring, giving customers the capability to mirror both native and IFS objects stored on iASPs. In addition to allowing users to mirror all OS/400 objects stored in an iASP, it makes it easier for users to do the initial move of data into iASPs, says Victor Szabo, DataMirror's manager of development for iCluster.
One of DataMirror's iCluster customers, a very large bank that did not want its name used, is already making good use of the expanded support for iASPs in iCluster 2.1. This particular company is using iCluster to replicate data from five OS/400 servers to a single backup machine. By setting up iASPs on the target machine, the company has been able to avoid library name conflicts, which greatly simplified things for them, Sakuth says.
"The only other alternative [to using iASPs] would have been to use five different partitions," he says, which would have put a larger burden on their iSeries hardware resources and would have led to greater cost.
The iCluster 2.1 also has new performance monitoring features that should help customers to better understand the current state of their iSeries and their iCluster mirroring. "We're giving a lot more information to the end user about what's occurring on the system," Sakuth says.
For example, the iCluster monitor will now provide administrators with the progress of mirroring certain objects. "Let's say a file reorganization is happening," Sakuth says. "Reorgs can take a significant amount of time. The product is doing everything correctly, but it might look like it has stalled, when it hasn't. It's just a normal system activity like a reorg."
Similarly, iCluster sports new autonomic functions that will enable it to recover from life's little bumps. For example, if there is a lock on an object that prevents iCluster from touching it (such as the reorg discussed above), iCluster will stop trying to replicate that object until it has been refreshed, and will then continue with replication. "It will handle it seamlessly under the covers," Sakuth says.
Finally, DataMirror is also giving users more flexibility to use different versions of OS/400 in their cluster. The iCluster 2.1 offers failover support for any combination of supported OS/400 releases that are current for IBM. Specifically, this should allow iCluster users to set up clusters using OS/400 V5R1 and OS/400 V5R3 (or i5/OS).