PreEmptive Analytics Data Hub User Guide

Endpoint Web Service

The Endpoint Web Service is the component that receives data from upstream clients, such as applications or possibly other Data Hubs. This section explains the configuration options for the Endpoint Web Service.

Maximum Request Size

The Endpoint Web Service has a maximum request size to protect against denial-of-service attacks from large requests. While the default setting of 4194304 bytes (4 MiB) is orders of magnitude above the typical message size, you may wish to adjust it for specific scenarios.

To change the maximum request size:

  1. Open [Application folder]\Web\Endpoint\Web.config.
  2. In the <system.webServer> section, under <security> and <requestFiltering>, locate the <requestLimits> element.
  3. Alter the maxAllowedContentLength attribute to indicate the maximum request size, in bytes.
  4. Save the file.

These changes take effect immediately, no restart is required.

Support for Cross-Domain Requests

In some cases, clients that send to the Data Hub will be web applications served on a different domain than the Data Hub. For instance, a web form hosted on might be instrumented with a PreEmptive Analytics API to send information about use of the form to a Data Hub hosted on Depending on the type of application, additional configuration may be necessary.

JavaScript API

No special configuration is required for use with the JavaScript API, because the Data Hub enables Cross-Origin Resource Sharing (CORS) by default.


If clients are sending messages from Microsoft Silverlight web applications and said web application is not hosted on the same domain as the Data Hub, additional configuration is required for security purposes via clientaccesspolicy.xml, crossdomain.xml, or both. After creating said file(s) with the appropriate permissions for your application, copy the file(s) to the [Application folder]\Web folder. No restart is required.

Data Hub Version 1.5.0. Copyright © 2015 PreEmptive Solutions, LLC