6. Known Issues

Note

For an updated list of critical known issues, see the Critical Issues List on the RTI Customer Portal at https://support.rti.com.

6.1. Coherent Changes not Propagated as Coherent Set

Persistence Service will propagate the samples inside a coherent change. However, it will propagate these samples individually, not as a coherent set.

6.2. TopicQueries not Supported in PERSISTENT Mode

Getting TopicQuery data from a Persistence Service instance configured to store data on disk is not currently supported.

Note

Getting TopicQuery data from a Persistence Service instance running in TRANSIENT (storing data in memory) mode is supported.

[RTI Issue ID PERSISTENCE-143]

6.3. <comm_ports> not Supported when Using Real-Time WAN Transport

Persistence Service can use the RTI Real-Time WAN Transport. However, the port configuration using <comm_ports> or the property dds.transport.UDPv4_WAN.builtin.comm_ports is not currently supported by Persistence Service.

[RTI Issue ID PERSISTENCE-206]

6.4. Persistence Service DataReaders Ignore Serialized Key Propagated with Dispose Updates

Persistence Service DataReaders ignore the serialized key propagated with dispose updates. Persistence Service DataWriters cannot propagate the serialized key with dispose, and therefore ignore the serialize_key_with_dispose setting on the DataWriter QoS.

[RTI Issue ID PERSISTENCE-221]

6.5. Synchronizing Data Samples between Persistence Service Instances Can Consume Significant Bandwidth

Synchronizing data samples between Persistence Service instances (using <synchronize_data>1</synchronize_data>; see Synchronizing of Persistence Service Instances in the Core Libraries User’s Manual) consumes a significant amount of bandwidth. This is because a Persistence Service instance does not keep track of which other Persistence Service instances have already received the data, causing unnecessary traffic.

For example:

  1. Start Persistence Service 1 (PS1) with synchronization enabled.

  2. Publish samples to PS1.

  3. Start PS2 with synchronization enabled.

  4. PS1 will send samples to PS2 since synchronization is enabled on both.

  5. PS2 will also send samples back to PS1 because it doesn’t know PS1 already received the samples. Each data sample will be sent N * (N - 1) times on the network for data synchronization to fully complete.

[RTI Issue ID PERSISTENCE-266]

6.6. Some tags in the XML configuration must be grouped in a strict order

The XML validator tools Persistence Service uses to validate XML configuration files adhere to the XML 1.0 specification, which doesn’t offer a way of defining collections of unordered tags that are both bounded and unbounded in occurrences.

This limitation is no longer present in XML 1.1. However, there are no C or C++ validators compliant with the XML 1.1 specification at the time of writing.

[RTI Issue ID CORE-14178]