Post Size Limit

3 min

Out-of-the-box, Apache Tomcat has a limit on the size of the request that can be made using the POST HTTP method. As your Essential Architecture Manager repository grows, this limit may be reached, causing an error when attempting to publish your repository from the modelling environment in Protege to the reporting environment, Essential Viewer. This article describes how this limit can be removed, enabling very large repositories to be published.

Remove POST size limit

When the repository is published from the Essential Modeler (Protege running an Essential project) to the Essential Viewer, a snapshot of the repository is sent to a Servlet running on Tomcat. From version 1.2 of Essential Architecture Manager, this snapshot is compressed to significantly reduce the size of the request that is made to Essential Viewer running on Tomcat.

However, when your repository snapshot reaches over 55MB in un-compressed form, Apache Tomcat must be configured to accept large amounts of data being sent to it, as the compressed size of the repository approaches the default 2MB POST size limit.

To remove this limit, edit the /conf/server.xml file in the Tomcat home directory as follows:

  • Find the tag entry for the HTTP 8080 connector

  • Add the maxPostSize="0" attribute and value to this tag such that it looks like:

  • maxHttpHeaderSize="8192"
    maxThreads="150"
    minSpareThreads="25"
    maxSpareThreads="75"
    enableLookups="false"
    redirectPort="8443"
    acceptCount="100"
    connectionTimeout="20000"
    disableUploadTimeout="true"
    maxPostSize="0" />

When you have completed editing the conf/server.xml file, save it and restart Apache Tomcat.

Updated 31 October 2023

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