webMathematica™ Wolfram - Wolfram Research

A page that contains an evaluateQueued tag is processed. This creates a job object, choosesa kernel pool, and submits the job to the job queue for that pool. The pool is chosen from the120 webMathematica User Guideto the id of the job. The state of the job is NEW when it is created and this moves to QUEUEDonce it is queued. Any request parameters that are sent with the page are saved to be usedwhen the computation is actually run.The request that contains the evaluatedQueued tag returns to the client. This might contain areference to the id of the job.At some future time a kernel in the pool becomes available. This kernel is acquired for thejob. At this point any AcquireKernelCode configuration will be called. The job changes statefrom QUEUED to RUNNING.The kernel executes the body of the evaluateQueued tag. It is subject to all the constraintsand limits of executing commands in webMathematica, and if one of these is exceeded then thecomputation will terminate and the errorType will be set to KERNELEXCEPTION. However, if thecomputation finished normally, the errorType is set to NOERROR and the result is stored in thejob.Organizing and Configuring a Queued PoolAny kernel pool can be used to run computations from an evaluateQueued tag. However, it istypically good practice to have a pool that is designated for queued computations. More informationabout kernel pools and how to set them up can be found in the kernel pools section. Usinga separate pool is advantageous because you can configure it in a way that is more useful for aqueued computation. For example, you might want to increase the KernelTimeLimit parameter,to increase it to some longer value. Most of the configuration parameters are useful for aqueued computation; you can find out more about configuring webMathematica in the sectionon configuration. Another advantage of a separate pool for queued calculations is that you havea pool available for normal calculations.Alternative Server TechnologiesThere are various different server technologies that can be used in conjunction with webMathematica.One basic strategy is to use URLs that refer to computations for a webMathematicaserver, a technique that should work for any server technology. This is particularly easy for imgtags.