4.2. Performance and Scalability

4.2.1. [Critical] Performance degradation with PERSISTENT mode in write-intensive scenarios

In release 7.3.1, the throughput of write-intensive scenarios for a Persistence Service instance running in PERSISTENT mode was lower than in previous releases. This regression was caused by performance optimizations introduced in that version to improve read-intensive scenarios (for example, when handling late joiners).

The fix for this issue improves the overall performance of write-intensive workloads. However, some degradation may still remain compared to earlier releases.

If this issue affects your application, please contact support@rti.com for further assistance.

[RTI Issue ID PERSISTENCE-485]

4.2.2. [Critical] Possible duplicate samples when data synchronization was enabled and Persistence Service was restarted *

Duplicate samples may have been sent by a restarted Persistence Service instance that was configured to persist samples to disk. These duplicates could be delivered to other Persistence Service instances that had already received the same samples.

This behavior occurred when <data_synchronization> was enabled using the following configuration:

<synchronization>
    <data_synchronization>
        <enable>true</enable>
    </data_synchronization>
</synchronization>

[RTI Issue ID PERSISTENCE-457]

4.2.3. [Major] Data in different Topics not persisted concurrently when synchronization enabled *

Release 7.5.0 introduced a new, more efficient synchronization protocol. When this protocol was enabled, data received by different PRSTDataReader and PRSTDataWriter pairs in Persistence Service was not processed concurrently, even if those pairs were associated with different Publishers and Subscribers.

For example, with the following configuration, contention occurred between the PRSTDataReader and PRSTDataWriter pairs for the Foo and Bar Topics:

<persistence_service name="PS">
        <synchronization>
            <data_synchronization>
                <enable>true</enable>
            </data_synchronization>
        </synchronization>
        <participant name="PRSTParticipant">
            <persistence_group name="PRSTGroup_0">
                <filter>Foo,Bar</filter>
                <single_publisher>false</single_publisher>
                <single_subscriber>false</single_subscriber>
            </persistence_group>
        </participant>
</persistence_service>

[RTI Issue ID PERSISTENCE-476]

* This bug does not affect you if you are upgrading from 7.3.x or earlier.