How large hosts encounter movement and the Web

Transactional integrity is an integral part of the mainframe era, but it is undergoing some transformation in the Web age. Development leaders view it as tough front-end Web users "bump" on the back-end of the mainframe. It is up to the software architect to balance the competing system goals.

On IBM Impact 2012, Las Vegas, the leading analyst and founder of RedMonk, James Governor, spoke about mainframe transactions in a conversation about IBM's Z-series servers and transaction integrity issues, according to his statement, Next, the mainframe and Web front-end have unique roles to play.

Governor said at the outset that software designers should strive to have a good understanding of those roles in order to inherit an increasingly stressful web application architecture.

"The scale of growth is really strong," he exclaimed. The development of the "Internet of Things" and the sharp growth of smartphone-type devices will put pressure on the system, he notes.

The load has risen significantly, as most large mainframe users agree. But large hosts support a key accommodation system that can handle these loads, said Misha Kravchenko, vice-president for information services at Marriott International.

Kravchenko estimates that Marriott uses a centralized operating system to process 800,000 nights of bookings and "no downtime" every day. The load has risen in recent years as Marriott strives to combine distributed loads with IBM's Z-class machines. Clearly, the web has become a subversive force for businesses that once relied on call centers, travel agents, and pure old-style phone support.

Once mobile apps really take off, he expects more intense growth. Marriott recently released a mobile tool to help travelers find nearby hotels, book rooms and verify bookings. Many of these mobile users are part of the Marriott Rewards program.

The core of understanding the deal is the grasp of the "CAP (consistency-availability-partition tolerance)" Theorem of computer scientist Eric Brewer, analyst governor said.

Brewer asserts that for these three features, system designers typically only authorize two of them in the design. In its banner's E-commerce system, the Cloud's man of the Amazon.com is famous for putting "final consistency" before instant trading consistency.

Host people take a very different view of these transaction characteristics. In the words of Governor is: "host the hope that all three have." ”

High integrity deal handling, big iron box and punk rock

For transactions that require brewer three features, the software Architect may do well when considering host design, but consider the isolation of other activities. As part of this effort, they may consider a separate ESB gateway. According to Kravchenko, a Marriott IT manager, they may also seek to avoid excessive XML data back and forth.

In its earlier version of the centralized accommodation system, a single XML fair ran 4 or 5 trips to the mainframe, Kravchenko said. Now, the situation has changed.

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"XML message delivery is now done in the host. That means fewer round-trip trips, "he said. At the same time, the use of host MIPS also declined, he noted.

The trading nature of Marriott's system differs from that of Amazon, an E-commerce site. Understanding this has hardened Marriott's plan to deal with the tight coupling of the room's confusing database.

When you buy a book on Amazon, you don't see the inventory, the data is often updated and can be described as the final consistency concept of the transaction. Kravchenko's point is that it doesn't matter to Amazon, because, for example, the price of a book doesn't always change, and if the communication with the customer is handled properly, the usability of the delay can be accepted.

The hotel room is different; its real-time, guaranteed availability is critical-because most business travellers have appeared on stormy nights.

Like everyone else, Marriott's flexible pricing of a block room has been carefully calculated. This "Revenue management pricing system is complex, and companies need to flex their pricing to the last room," Kravchenko said.

"We need a database. It's connected to the inventory. Amazon is different, "he said.

Cloud trading types can cover many aspects, but not all of them.

Cloud providers have rebuilt the main model's transactions for the Web age in some way. Governor skillfully summed up the new trading field with a musical analogy: "Young Turks has come here to build his own system." They are trying to do what the mainframe has done. ”

Amazon, Google and Facebook have already used a simpler way to reduce complexity, much like punk music that reshaped rock and roll in the late 70.

"They say, ' We only use four chords, '" Governor joked.

As for the mainframe, Governor said: "Let's figure out what it's best at and then maybe learn something from punk music." ”