Error: HTTP Status 400 - Bad Request (when calling a Database Security server XML-API URL)

To fix this issue, increase the maximum HTTP header size allowed by Apache Catalina:

Open <installDir>\conf\server.xml in a text editor.
NOTE: The value <installDir> is the root directory for Database Security Server.

For Windows, the default location is C:\Program Files\Mcafee\McAfee Database Security\

For Linux, the default location is /usr/local/mfe-dbs-server/

Locate the Connector port entry:

For Database Security v4.8.2 and earlier , look for the two connector tags, HTTP (TCP port 8080 ) and HTTPS (TCP port 8443 ):
<Connector port= "8080" relaxedQueryChars="${dbsec.relaxed.query.chars}" server="Database Security WebServer"
maxHttpHeaderSize= "8192" maxThreads="150" enableLookups="false" redirectPort="8443" acceptCount="100" connectionTimeout="20000" disableUploadTimeout="true" maxPostSize="16777216"/>
<Connector port= "8443" relaxedQueryChars="${dbsec.relaxed.query.chars}" server="Database Security WebServer"
maxHttpHeaderSize= "8192" maxThreads="150" enableLookups="false" disableUploadTimeout="true" acceptCount="100"

For Database Security v4.8.3 and later , look for the single HTTPS (TCP port 8443) tag:
<Connector port= "8443" relaxedQueryChars="${dbsec.relaxed.query.chars}" server="Database Security WebServer"
maxHttpHeaderSize= "8192" maxThreads="150" enableLookups="false" disableUploadTimeout="true" acceptCount="100"

Edit the connector(s) properties as follows:
HTTP:
<Connector port= "8080" relaxedQueryChars="${dbsec.relaxed.query.chars}" server="Database Security WebServer"
maxHttpHeaderSize= "65536" maxThreads="150" enableLookups="false" redirectPort="8443" acceptCount="100" connectionTimeout="20000" disableUploadTimeout="true" maxPostSize="16777216"/>
HTTPS:
<Connector port= "8443" relaxedQueryChars="${dbsec.relaxed.query.chars}" server="Database Security WebServer"
maxHttpHeaderSize= "65536" maxThreads="150" enableLookups="false" disableUploadTimeout="true" acceptCount="100"

Save the file.

Restart the Database Security Server service.