DDS 1.5 RTF Avatar
  1. OMG Issue

DDS15 — DataReader semantics for historical data are insufficient

  • Key: DDS15-52
  • Legacy Issue Number: 10805
  • Status: open  
  • Source: Anonymous
  • Summary:

    The current specification provides no solution for the following two use-cases:
    · A Volatile DataReader can receive data from a Transient or persistent DataWriter so it may also be interested in historical data. However a DataReader cannot receive historical data. Just making the DataReader Transient does not solve the problem because the DataReader may also be interested in volatile data.
    · A Transient or Persistent DataReader may not be interested in historical data, there is no way to avoid receiving historical data. A DataReader may be e.g. Transient to avoid receiving data from volatile DataWriters, in addition there may be no interest in historical data.

    Separate the control of receiving historical data from the DataReaders durability interest. The DataReaders Durability interest will specify from which DataWriter it will accept data. A separate call will control (ask for) the retrieval of historical data.
    Add the following method
    ReturnCode_t get_historical_data(Duration_t max_wait)
    And Transient and Persistent DataReaders should not automatically receive historical data. A consequence is that this invalidates the method
    ReturnCode_t wait_for_historical_data(Duration_t max_wait).

  • Reported: DDS 1.2 — Mon, 5 Mar 2007 05:00 GMT
  • Updated: Fri, 3 May 2019 01:36 GMT