Cloud Provides A Third HA Option
September 20, 2017 Alex Woodie
In the third part of our series on IBM i high availability options, we’re looking up — to the cloud, that is.
If you’re in the market to implement an IBM i high availability solution – and the best data we’ve seen indicates that many IBM i shops are shopping in 2017 – then you basically have three options to choose from: logical replication software solutions, IBM’s Power HA hardware solution, and a cloud-based HA solution.
Here’s the good news: There are literally dozens of managed service providers (MSPs) plying the IBM i high availability waters. When you include disaster recovery, the combination of HA and DR arguably is the most popular workload for MSPs in the IBM i ecosystem.
Benefits of Cloud HA
Customers can ring up compelling benefits from getting HA from the cloud. The big one, of course, is eliminating the need to have a secondary IBM i server as a hot standby, which can be an expensive proposition (although IBM’s incentives can soften that burden).
Instead of buying and running their own secondary server, IBM i customers essentially rent room on an MSP’s Power Systems server on a monthly or yearly basis. An MSP can host several clients’ IBM i HA workloads on a single machine, and pass the savings on to the client.
The cloud approach also saves customers from the expense and hassle of dealing with HA software. Many logical replication solutions require daily care and feeding to ensure that everything is in sync between the primary and the secondary IBM i machines, and ensuring that everything is failover-ready. When you work with an MSP, those concerns (mostly) become their responsibility.
Despite all the benefits of cloud-based HA, there are some downsides that IBM i shops should be aware of.
First and foremost, clients should be willing to cede control of managing the high availability to the MSP partner. In most instances, this shouldn’t be a big deal, because the MSP is likely quite familiar with the day-to-day requirements and the intricacies of the logical replication solution they’re using (some MSPs support PowerHA, but they are in the minority). In any event, the IBM i customer should be aware that they’re reliant on the MSP for setting up, monitoring, managing, testing role swaps, and ultimately conducting emergency failovers.
Security also must be mentioned in this conversation. The MSP partner is storing a full copy of your database on its server, so you must ensure your partner has adequate data security protections in place. Anecdotal evidence suggests that the average MSP is as good, if not better, at following security best-practices than IBM i shops themselves, but there will always be exceptions.
Check the MSP’s investment in data protection. Is your database backed up to a tape and stored offsite, or does that remain your responsibility? Does the MSP store IBM i data on non-IBM i storage servers, such as a Windows-based file share? Can they guarantee that the data will be recoverable in the event of a disaster? Do they have all the requisite UPS systems, batteries, and generators required to stay in business during a power outage?
There is also the possibility that a disaster will strike that exceeds the MSP’s capability to ensure HA service, particularly if all its clients are clustered in the same FEMA region. For this reason, many IBM i shops opt to pay extra to have a dedicated IBM i server in the MSP’s data center. It’s also worth checking to see how many data centers the MSP owns, or has rights to use, and in what parts of the country.
Also, some MSPs may charge you a fee to declare a disaster, which is not something you would have to pay if you were running everything yourself. Some MSPs also will not let you declare a disaster, and thus initiate a failover to their servers, unless a formal declaration of disaster has been made by the state governor or the federal government.
There are many advantages to using cloud HA solutions, both in terms of convenience and cost. But customers should not embark upon a cloud-based HA system without knowing all the ins and outs of what they’re getting into.
In the next article in this series, we’ll introduce you to some of the vendors offering cloud-based HA in the IBM i ecosystem, and take a look at the specifics of their offerings.