Leak in Kundera 2.12 and Datastax Java Driver

[vanessaschissato]

I would to report that we have notice a memory leak when switched from Thrift to Datastax Java Driver that crashes our application (kundera 2.12).

[mevivs]

Could you please share few more details? -Vivek

[vanessaschissato]

We have an application that makes massive inserts and reads from and to cassandra and we have identified a leak that makes our application turn down. Debugging the application, we have isolated the problem and realize that it is in the use of Kundera with DataStax Driver.

[chhavigangwal]

Can you please share the code snippet or sample app which leads to this leak ?

Chhavi

[Odyldzhon]

Hi guys! I faced with the same issue. This is details which can help to identify the problem

• Gradle dependency :

compile("com.impetus.kundera.client:kundera-cassandra-ds-driver:3.4")

• persistence.xml configuration :

...
        <properties>
           ...
            <property name="kundera.dialect" value="cassandra"/>
            <property name="kundera.client.lookup.class"
                value="com.impetus.kundera.client.cassandra.dsdriver.DSClientFactory" />
            <property name="kundera.batch.size" value="5000" />
        </properties>
...

• How I create EntityManager :

    @PersistenceContext(
            unitName = "cassandra",
            type = PersistenceContextType.EXTENDED,
            properties = {
                    @PersistenceProperty(name = "consistency.level", value = "QUORUM"),
                    @PersistenceProperty(name = CassandraConstants.CQL_VERSION,
                            value = CassandraConstants.CQL_VERSION_3_0)
            }
    )
    protected EntityManager em;

• How I create entities via EntityManager:

        for (File file : files) {
            csvParser.beginParsing(file, StandardCharsets.ISO_8859_1);
            String[] row;
            while ((row = csvParser.parseNext()) != null) {
                try {
                   Entity entity = new Entity();
                    ...
                    em.save(entity);
                } catch (Throwable e) { // NOSONAR
                    LOGGER.error("Error occured during parsing row :" + Arrays.toString(row), e);
                }
            }
            csvParser.stopParsing();
        }

I suppose that after auto flush operation, GC cannot remove flushed entities. As workaround I can call clear method explicitly for EntityManager but then no sense of using auto flush operation.

Maybe I do something wrong? If it's bug, maybe there is workaround for this problem?