Technology
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| Q: |
Can I use gridMathematica for the same
calculations for which I use Mathematica? |
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Yes, you can. Since gridMathematica uses Mathematica as
its primary component, it has access to all of Mathematica's
functionality. In addition, gridMathematica has a
few functions that are not included
with Mathematica.
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| Q: |
What kind of computations profit most from gridMathematica? |
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Computations that can be broken into smaller pieces and that don't involve
lots of communication overhead profit most. Examples
include running many scenarios of the same computation, such as random number
generation (e.g., Monte Carlo) or perturbation problems, and doing
independent searches of large numbers of parameter spaces or different cases.
The speed gains are also dependent on the speed of your communication system.
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| Q: |
Will gridMathematica make all of my Mathematica
computations faster? |
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Not all Mathematica commands can be broken up
into pieces capable of being distributed across a grid. Commands such as
Integrate, Solve,
and NDSolve
can be evaluated only
on a single kernel. However, some commands, such as Map
and
Table,
have parallel equivalents, such as ParallelMap and
ParallelTable. Also, if a
series of commands needs to be carried out, a set of separate kernels can handle
these tasks faster by having each kernel handle one of the
commands rather than waiting for one kernel to finish all of them. ParallelEvaluate will try to parallelize an
operation automatically, assuming it's possible.
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| Q: |
How much faster will my programs run using
gridMathematica compared to Mathematica? |
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The speedup depends on the type of calculation being performed, the
efficiency of the algorithm, and the speed of your hardware and
communication. Since this will vary on a case-by-case basis, it is
not possible to provide a number that would be true in all
circumstances. In a best-case scenario, the speedup would be linear;
in other words, if you double the number of CPUs the speed doubles. In
most real-world cases there is communication latency, and many
problems do not parallelize well, so the speedup will be less than
linear. If a program is well written, runs on fast hardware with low
communication latency, and parallelizes well, linear speedups are
possible.
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| Q: |
Will application packages work with
gridMathematica? |
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Yes, they will. You need to have one copy of the application
package per process.
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| Q: |
Can I connect gridMathematica to a
database? |
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Yes, you can. gridMathematica leverages Mathematica's
built-in support for universal database
connectivity.
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| Q: |
On what types of grids and clusters will gridMathematica
run? |
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gridMathematica is supported on any platform on
which Mathematica is supported, including
multiple-processor machines, clusters, and grids. If there are several
distributed computers in your grid, they also need to be able to communicate with
each other via TCP/IP.
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| Q: |
On which platforms does gridMathematica support 64-bit processing? |
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gridMathematica supports 64-bit processing on all major platforms. For a complete list, see the platform support page.
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| Q: |
What is the performance overhead
of gridMathematica? |
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The main overhead is communication, and it strongly depends on the
communication fabric you have for your grid. A shared-memory parallel
machine has significantly lower communication overhead than a
distributed-memory, networked set of machines.
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| Q: |
Is gridMathematica using
MPI? |
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No, it isn't. gridMathematica offers many of the same features
that were the goals of the MPI developers: it runs transparently on
heterogeneous clusters, and it provides a virtual computing model that
hides architectural differences. However, the messaging interface is
optimized for communications between Mathematica kernels and
other programs that communicate via the MathLink API so as to
avoid a requirement for large amounts of extra information with each
message and the need for complex encoding or decoding of message
headers.
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| Q: |
What happens if a kernel fails during the course of an
evaluation? |
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gridMathematica provides recovery methods that redistribute
remaining processes in the event that a kernel failure occurs. Network
issues or software issues can cause this failure, and any results that
were expected from the failed kernel will be lost.
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| Q: |
Does gridMathematica run faster if I use more
processors? |
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It can run faster, but the speed improvement depends on factors such as the
efficiency of your algorithm and the network communication speed.
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| Q: |
How thoroughly has gridMathematica been tested? |
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Mathematica is extensively tested by
Wolfram Research. Every week throughout the development process, it
is subjected to an extensive battery of manual and automated testing,
including comparisons with known results of nearly a half-million
computations (chosen from books of tables, bug reports, documented
behavior, and other Wolfram-Research-generated tests).
In addition, Mathematica's
ability to solve many problems in a variety of different ways allows
for self-checking within the system.
For these reasons, Mathematica is renowned as the
technical system delivering the most trustworthy and accurate
answers. Because gridMathematica
uses Mathematica as its primary component, gridMathematica
and Mathematica functionality have
been tested to the same extent.
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| Q: |
Does gridMathematica work on a system using Myrinet,
Infiniband, or Quadratics? |
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Yes, it does. These technologies can use TCP/IP, which provides the
communication services needed for gridMathematica to function.
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| Q: |
What is the relationship between gridMathematica and
Parallel Computing Toolkit? |
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gridMathematica is a bundling of Network Mathematica and Parallel Computing
Toolkit and so it provides a complete solution for people
without Mathematica already installed. Parallel Computing
Toolkit is an application package that allows
current Mathematica or Network Mathematica users to
perform computations in parallel. This requires that users already
have Mathematica or Network Mathematica installed.
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Deployment and Administration
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| Q: |
How many gridMathematica increments should I purchase to
provide efficient operation? |
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gridMathematica is completely flexible in that it does not assume that
a certain number of processes are available. Developers of parallel processing
programs typically write their code so that it is tailored to the environment.
If they have access to an eight-node cluster, they can write their code to use
that number of nodes. The same is true for larger clusters. The high-level
commands such as RemoteEvaluate allow the programmer to manually
specify which node handles a particular evaluation. On the other hand,
ParallelMap
automatically maps an expression onto a list of other expressions in
parallel, regardless of the number of nodes. The method used by the
programmer determines how many nodes are desirable.
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| Q: |
What network security model is used by
gridMathematica? |
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gridMathematica does not implement any security model. However, with
mechanisms such as SSH, gridMathematica can be set up to communicate
via whatever security models those mechanisms have in place. Details for doing
this may vary depending on the platform.
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| Q: |
Does gridMathematica work with MathLM and
MonitorLM? |
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gridMathematica comes with MathLM, the license manager provided
by Wolfram Research. MonitorLM is also provided and allows an
administrator to monitor the activity of the license manager. Both applications
work fine with gridMathematica.
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| Q: |
Do I need to dedicate one computer for running
MathLM? |
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Any computer capable of communicating with the cluster can be used to run
MathLM. However, this machine must be able to serve passwords only to
machines covered under the gridMathematica license. It cannot be used
to serve passwords to machines that may exist under a separate
Mathematica license.
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| Q: |
Do I have to install Mathematica on each node? |
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You don't necessarily have to. Mathematica needs to be accessible to
every node on your cluster, but this can be achieved either by installing
Mathematica on each node or by sharing Mathematica using a file
server that allows each node to access Mathematica.
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Licensing
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| Q: |
How are licenses handled for gridMathematica? |
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Just as in Network Mathematica, gridMathematica
uses MathLM,
Wolfram Research's license-management tool for
controlling and distributing Mathematica network
processes. This means that you do not need separate passwords for each
node in the cluster. Once MathLM is running, it will
automatically distribute passwords to all of the machines on the
cluster. gridMathematica comes in increments of
eight processes and MathLM will be able to handle up to as many
processes as your total increments allow. For example, two increments of
gridMathematica provide up to 16 separate Mathematica
processes, and MathLM will be able to automatically serve up to
16 passwords.
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| Q: |
Can I add gridMathematica to my current purchase program? |
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Yes, you can. Contact Wolfram Research or your reseller to do so.
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| Q: |
If I currently own Mathematica, can I upgrade to
gridMathematica? |
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Yes. Contact Wolfram Research
or your reseller for more
information.
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| Q: |
Can I share gridMathematica and Network Mathematica
license keys? |
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No, you can't. The license keys for gridMathematica are different from
those for Network Mathematica.
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| Q: |
Can I use Mathematica application packages with
gridMathematica? |
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Yes, you can, but you will need one copy of the
application package for each grid node.
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| Q: |
How many users can use my cluster simultaneously? |
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Each gridMathematica comes with one controlling process, so that means
you can have one user per gridMathematica.
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| Q: |
I am a student. How can I get a copy of
gridMathematica? |
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Student pricing is not available for gridMathematica; however, you may
want to see if your school or university has a gridMathematica license
that you can access.
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| Q: |
If I currently own an older version of gridMathematica,
can I upgrade to the most recent version? |
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Currently, you can upgrade from any earlier version of
gridMathematica. Contact
Wolfram Research or your
reseller for details.
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| Q: |
Should I purchase gridMathematica or Parallel
Computing Toolkit? |
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gridMathematica is intended for individuals who don't currently
own Mathematica and so it includes everything necessary,
including Mathematica. If you already own Network Mathematica, then all you
need is a network license for Parallel Computing
Toolkit. gridMathematica is also useful for
organizations that wish to add dedicated parallel programming
capability to their existing license. If you already own Mathematica,
contact Wolfram Research or your reseller to upgrade.
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Support and Training
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| Q: |
Does Wolfram Research offer a service contract for
gridMathematica? |
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Yes, it does. gridMathematica comes with a one-year subscription to Premier Service, renewable indefinitely.
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| Q: |
Is gridMathematica consulting available? |
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Yes, it is. Please see the list of accredited Mathematica consultants for details
and contact information.
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| Q: |
Does Wolfram Research offer gridMathematica training? |
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Yes, it does. Current courses that are relevant for anyone interested
in parallel computing with Mathematica and
gridMathematica include M225: Grid Computing
with Mathematica and M245: Parallel
Computation, and the free online seminar S17: Applied Parallel Computation with gridMathematica.
In addition, a host of other courses are offered
pertaining to general Mathematica programming and use.
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