Managing complex data sets with PolyServe Matrix Server

							Managing complex data sets with PolyServe Matrix Server

The amount of data managed by IT departments is growing at an ever-increasing rate –
as are the potential problems it creates. Managing access, dealing with hardware
failures and increased workloads are a growing challenge for IT professionals
everywhere. Fortunately, there is help available, in the form of the PolyServe Matrix
Server. This neat device simplifies problems and adds a much-needed layer of
reliability.

In today’s business world, databases are literally everywhere. They underpin mail servers
such as Microsoft Exchange, hold documents in collaboration solutions such as SharePoint
and Domino and are at the heart of document management products. Business Intelligence is
all about mining corporate data to find a competitive edge. And the more databases we have,
the more users there are that need to access and query the data.

As the amount of data has grown, the logical and computation part of databases has – out of
necessity – been separated from the physical data itself. In many datacentres today, the
physical data is located on the Storage Area Network while the actual processing of the data
is done by application and database servers. The larger quantities of data has also meant
greater numbers of actual servers – while work teams are increasingly spread out across
continents and even the world. But of course, to provide the most efficient response, servers
and work teams need to be located as close together as possible.

When a workload needs to be moved or when a server fails, users need to migrate their work
to another server, as seamlessly, and quickly, as possible. Should the network or the backend
storage systems fail, then data requests need to be directed to other locations where there are
copies of the data.

All this is done through clustering and workload balancing. But here’s the real problem. Even
the slightest problem for one data management application can have a serious knock-on affect
that can cause data to become unavailable to other applications. This can cause a cascade
failure of applications and, put simply, spell big and expensive problems for businesses of all
types.

This is where PolyServe Matrix Server comes in.

The PolyServe Matrix Server (PMS) uses a number of technologies to ensure high availability
of data and high throughput of workload without requiring large numbers of operators or
excessively complex systems.

To abstract the physical location of the data from the users, PMS uses a virtual device layer
(VDL) that hides where the data is. This VDL does several things. Firstly it ensures that PMS
always sees the underlying data location as the same name. Even if the real location has to be
changed because of a network or hardware failure, PMS and the applications that sit on top of
it never know.
VDL also acts as a gatekeeper to prevent any application trying to carry out an action that
would impact on other applications sharing the data storage. An example of this is preventing
a device from being formatted when it is being used by other applications.

To ensure data consistency, PMS uses a Symmetric Distributed Lock Manager (DLM).
Unlike a lot of distributed data solutions that rely on a single master locking server that can
become a serious bottleneck, DLM is deployed on all application servers that will access the
data.

Applications lock data and records in order to update them or when they add new
information. DLM uses a proprietary locking protocol so that all the servers know what is
locked and use that to minimise delays in writing data. Such locking solutions are not
uncommon but while other vendors broadcast information about locks indiscriminately across
the network causing massive increases in traffic, the DLM locking protocol targets just the
servers that are sharing the data.

To speed up the delivery of data to the user or application, data is often moved from the
database to a local cache. This means that data is available at the speed of the system not the
network. The problem here is that caches can quickly get out of date and users can be
working on old data sets. By using a Cache Coherency mechanism, PMS allows the different
cache pools to know what has been updated so that they can always serve the user or
application the latest set of data.

To keep all of this together across multiple databases, storage devices, users, servers and
physical locations, PMS has a single management interface. This reduces operator time and
ensures that the corporate data assets can be easily managed. It also adds another level of high
availability as the management can be done from any site.

Keeping track of, and managing access to, large amounts of complex data is critical to
keeping a business running. PMS provides a software layer that brings together the hardware
and the applications to provide users with the highest availability of data.