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The digest of current topics on Continuous Processing Architectures. More than Business Continuity Planning. BCP tells you how to recover from the effects of downtime. CPA tells you how to avoid the effects of downtime. Thanks to This Month's Availability Digest Sponsor
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In this issue:
Social Media Availability and Performance EMC's SRDF Data-Replication Engine
Browse through our Useful Links. Check our article archive for complete articles. Sign up for your free subscription. Join us on our Continuous Availability Forum. |
Japan – A Lesson in Business Continuity Planning
My wife and I were on our way to a South Pacific vacation when we landed at our scheduled layover in Tokyo on March 11th. Twenty minutes after we entered the terminal at Narita airport, the floor began to shake. We were experiencing the fifth largest earthquake ever recorded, one that moved Japan eight feet closer to California. Even though the epicenter was some 200 kilometers north of Tokyo, it was virtually impossible to stand up – everyone was on their hands and knees.
Fortunately for us, the terminal building sustained little damage; but all flights were cancelled. So we spent the night on a cold floor.
Hundreds of passengers on our air carrier had to be rerouted – this was going to take days at the passenger service counter. I tried to call our carrier, but the cell phone towers were down. Pay phones were useless because many land lines were out. Somehow, the wireless service in the airport survived; and we were able to reschedule on a plane the next day via Skype. The lack of communications did not affect just us. Though there was little physical damage in Tokyo, data centers were knocked offline for days until communication was restored. How many companies were prepared for this level of disaster? How many had backup satellite links? How many were dealt a fatal blow? Business continuity planning is not just an exercise. It is a necessity that can save your company.
Dr. Bill Highleyman, Managing Editor | ||
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Never AgainVodafone Downed by Burglars
We can imagine many disasters that can take down a data center – floods, fires, earthquakes, explosions. But what about theft of equipment? That is what happened to a Vodafone telephone exchange late one night. The thieves made off with computer and network equipment worth millions of pounds. The equipment was that used to identify mobile phones and to connect them to Vodafone’s cellular network. Without it, the network was down.
Mobile phone service has become critical to the operation of many businesses. Not being able to communicate for most of the day is bad enough. But what seemed to really get people angry was the lack of communication from Vodafone. Customers did not know what was happening nor when to expect the restoration of mobile services.
Other aspects of this
incident also stand out. Where was the physical security for the
building?
And where was Vodafone’s business continuity plan? Surely, they had considered the recovery from a data-center failure. Or had they?
Best PracticesIPv6 Is Here – Like It or Not
In our article almost two years ago, we repeated the alarm raised by many that the decrepit IPv4 address space of 32 bits was about to be depleted. IPv6, with its 128-bit address space, was set to become king. At the time of our article, the assignment of the last available IPv4 address was expected to be in mid-2011. We are now approaching mid-2011, and the IPv4 addresses have, in fact, been depleted. Will the Internet collapse?
Of course not, but the transition to the new protocol specification is not trivial. If you elect not to convert, you will survive for a while; but your Internet experience will become more and more painful. Help is here. In a recent article, Vinton Cerf, who is recognized as one of the fathers of the Internet along with Robert Kahn, collaborates with fellow Google associate Thomas Limoncelli to relate the experiences of Google, Comcast, and Nokia as they successfully navigated the conversion from IPv4 to IPv6. The result is one simple message. As the old KISS saying goes, “Keep it simple, stupid.”
Availability Topics
Social Media Availability and Performance
Though social networking may not seem critical from a business viewpoint, to many individuals it is. Not having access to Facebook or not being able to tweet when we want to can ruin a day.
The availability of social networks and their responsiveness is becoming a factor in the quality of life of our everyday activities. Forrester’s research indicates that as of 2010, 59% of all Internet users use social networks; and 70% consume information from social networks. Users are not just teenagers – 70% of active conversationalists are over 30.
Monitoring social-media web sites has shown a wide range of availability and performance. In 2010, Twitter was at the bottom of the list in both of these categories. Twitter’s experience with the 2010 World Cup and the recent demonstrations in the Middle East illustrate the effect that worldwide events can have on social networks. As demand for real-time personal information increases, so do the expectations for availability and performance. Social networks such as Facebook, Twitter, and LinkedIn must scale to meet such demands; and in the future, they must be structured to provide telephone-grade availability.
Product Reviews
EMC’s SRDF Data-Replication Engine
In most of our reviews of data-replication engines, we have focused on server-based logical replicators. They provide a consistent copy of a source database on a remote target database. Server-based replication requires the use of host-system resources. This usage is eliminated if a storage array is used and if data replication is performed by the storage array itself.Many storage-array replicators replicate disk blocks as they are physically written to the source storage array. However, the contents of the target storage-array disks do not represent a consistent view of the database since much of the current content of the database is maintained in cache at the source.Storage arrays that provide cache storage can replicate disk blocks from cache as they are changed. Therefore, the target storage array always represents a consistent copy of the source database.
Such a replication engine is EMC’s Symmetrix Remote Data Facility (SRDF). SRDF provides consistent target database copies, kept current via either asynchronous or synchronous replication. SRDF supports mainframes, AIX systems, and Windows, Linux, and UNIX open systems. A variety of configurations are supported. Of particular use is SRDF/Star, which provides synchronous replication to a nearby data bunker and asynchronous replication to a remote disaster-recovery site.
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The Availability Digest is published monthly. it may be distributed freely. Please pass it on to an associate. Managing Editor - Dr. Bill Highleyman editor@availabilitydigest.com. © 2011 Sombers Associates, Inc., and W. H. Highleyman | |||
