Class AllocateServerSocketServlet

  • All Implemented Interfaces:
    Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig, CartePluginInterface, CarteServletInterface

    public class AllocateServerSocketServlet
    extends BaseHttpServlet
    implements CartePluginInterface
    This servlet allows a client (TransSplitter in our case) to ask for a port number.
    This port number will be allocated in such a way that the port number is unique for a given hostname.
    This in turn will ensure that all the slaves will use valid port numbers, even if multiple slaves run on the same host.
    See Also:
    Serialized Form
    • Constructor Detail

      • AllocateServerSocketServlet

        public AllocateServerSocketServlet()
      • AllocateServerSocketServlet

        public AllocateServerSocketServlet​(TransformationMap transformationMap)
    • Method Detail

      • doGet

        public void doGet​(javax.servlet.http.HttpServletRequest request,
                          javax.servlet.http.HttpServletResponse response)
                   throws javax.servlet.ServletException,



        Allocates port to use by client. Allows any client to ask for a port number to use. This is necessary several slaves can be run on the same host. The method ensures the port number is unique for host name provided and makes sure the slaves are using valid port numbers. Data communication across a cluster of Carte servers happens through TCP/IP sockets. Slave transformations sometimes open (or listen to) tens to hundreds of sockets. When you want to allocate the port numbers for data communication between slave transformation in a kettle clustering run, you need unique combinations of all the parameters below. port number will be returned in the Response object. If an error occurred you'll receive html output describing the problem. HTTP status code of such response is 500.

        Example Request:

            GET /kettle/allocateSocket/?xml=Y&rangeStart=100&host=locahost&id=clust&trans=my_trans&sourceSlave=slave_1


        name description type
        xml Boolean flag set to either Y or N describing if xml or html reply should be produced. boolean, optional
        rangeStart Port number to start looking from. integer
        host Port's host. query
        id Carte container id. query
        trans Running transformation id. query
        sourceSlave Name of the source slave server. query
        sourceStep Port number step used on source slave server. integer
        sourceCopy Number of copies of the step on source server. integer
        targetSlave Name of the target slave server. query
        targetStep Port number step used on target slave server. integer
        targetCopy Number of copies of the step on target server. integer

        Response Body

        element: (custom)
        media types: text/xml, text/html

        Response wraps port number that was allocated or error stack trace if an error occurred. Response HTTP code is 200 if there were no errors. Otherwise it is 500.

        Example Response:


        Status Codes

        code description
        200 Request was processed and XML response is returned.
        500 Internal server error occurs during request processing. This might also be caused by missing request parameter.
        Specified by:
        doGet in interface CartePluginInterface
        doGet in class javax.servlet.http.HttpServlet