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ITPilot 5.5
User Guide
Introduction
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conversion Server, which transforms PDF documents to HTML, using Adobe
Acrobat Professional, and is automatically started. This server will be used by
the Generation Tool to perform the required conversions. The execution time
conversions are performed by the Execution Environment’s PDF conversion
server, which is a separate component.
In addition and although it does not belong to this environment per se, generator
tools may need to store the wrapper created. The Wrapper Server in the Execution
Environment is used to do this (see next section 1.1.3).
1.1.3
Execution Environment
This is the continued operation environment, in which the user can use previously
created wrappers to launch queries on isolated sources. This use may be direct
(through an API or publishing the wrapper as a Web Service) or through other
products such as Denodo Virtual DataPort, with which Denodo ITPilot is fully
integrated. The components that make up this environment are as follows:
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Wrapper Server: this is the component responsible for storing wrappers for
accessing. These include a remote interface for statement execution.
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Browser Pool: when a wrapper is executed, a browser type can be selected:
MSIE browser (automatic navigation module based on Microsoft Internet
Explorer [IE]) or Denodo browser (based in HTTP as an access method). In
this case, the Wrapper Server uses the Browser Pool to minimize the time
required to create browser instances. This pool can be configured from the
administration tool.
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PDF Conversion Server: this is the component responsible for transforming
PDF documents to HTML using Adobe Acrobat Professional, so their content
can be extracted by Denodo ITPilot.
1.1.4
Verification Environment
The Verification Environment adds functionality on top of the Execution Environment,
and complements it by verifying the deployed wrappers operation, and reducing the
manual effort. As Web sources are autonomous and independent of the wrappers,
they can change over time, and these changes can invalidate the current access
mode, whereby the wrappers no longer extract the data properly. Denodo ITPilot
offers an automated verification tool that detects the changes referred to above.
Although this will be dealt with in more depth in section 5.4, its basic functioning is
as follows:
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The Wrapper Server stores all the wrappers in each of the Web sources.
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The system periodically checks each wrapper for changes, monitoring the
results of the queries executed against them.
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When a change is detected in a source, the system sends a notification of the
change.
The components of this environment, apart from those already mentioned in the
execution environment, are as follows:
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Verification Server: component responsible for detecting automatically any
change happened in the sources and for notifying those changes. It
communicates with the Wrapper Server to request all the wrappers to verify,
and to obtain the query execution results over them (which will be used to
check possible changes).