StackOverflowError in camel-sql-binding quickstart

[igarashitm]

It just disappeared from my workspace, so post a reminder for next time. I and David saw this infinite loop in camel-sql-binding quickstart today, but is not 100% reproducible.

java.lang.StackOverflowError

        at org.switchyard.test.MockHandler.waitFor(MockHandler.java:169)

        at org.switchyard.test.MockHandler.waitForOKMessage(MockHandler.java:149)

        at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:68)

        at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:76)

        at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:76)

        at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:76)

        at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:76)

        at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:76)

        ........

[dward]

Yup.  Here's the top of the test.  It's not 100%, but it seems like:

1. cd quickstarts/ ; mvn clean install = ERROR

2. cd quickstarts/camel-sql-binding/ ; mvn clean install = NO ERROR

3. cd quickstarts; mvn clean install -DskipTests=true ; mvn test = NO ERROR

1. -------------------------------------------------------------------------------
2. Test set: org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest
3. -------------------------------------------------------------------------------
4. Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 2.913 sec <<< FAILURE!
5. shouldRetrieveGreetings(org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest)  Time elapsed: 0.148 sec  <<< ERROR!
6. java.lang.StackOverflowError
7.     at java.util.concurrent.LinkedBlockingQueue.size(LinkedBlockingQueue.java:260)
8.     at org.switchyard.test.MockHandler.waitFor(MockHandler.java:172)
9.     at org.switchyard.test.MockHandler.waitForOKMessage(MockHandler.java:149)
10.     at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:68)
11.     at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:76)
12.     at org.switchyard.quickstarts.camel.sql.CamelSqlRetrieveTest.getContents(CamelSqlRetrieveTest.java:76)

[mageshbk]

Well I had the same issue too. Thought that it could be a *Windows only* issue so kept quite. Here is what I do to solve it:

If I change the test like this it goes through

    private List<Greeting> getContents(MockHandler handler) {
        handler.waitForOKMessage();
        List<Greeting> greetings = new ArrayList<Greeting>();
        for (Exchange exchange : handler.getMessages()) {
            Greeting[] content = exchange.getMessage().getContent(Greeting[].class);
            if (content != null) {
                greetings.addAll(Arrays.asList(content));
            }
            try {
                Thread.sleep(100);
            }
            catch (InterruptedException ie) {
                // Ignore
            }
        }
        return greetings.size() == 0 ? getContents(handler) : greetings;
    }

Magesh

[dward]

Magesh, would you mind submitting a pull request to fix it?

[dward]

Actually, I see you're offline. Nevermind then, I'll submit one.

[dward]

https://issues.jboss.org/browse/SWITCHYARD-1273

[splatch]

Hey,

It's my fault. Hows about setting waitTimeout in MockHandler to 1000 ms?

Cheers,

Lukasz

[dward]

1. I'm having a hard time seeing how a race condition causes a stack overflow error...
2. Would changing the waitTimeout in MockHandler be effectively the same thing as introducting a wait in the test per Magesh's fix?
3. Can we envision any other fix that doesn't depend on an arbitrary wait, so it is dependable?

[splatch]

David,

The retrieve binding has 1 second initial delay and poll database every second. I think 2-4 second for wait timeout should be ok, however first poll may return empty result. That's why test code waits untill something is returned by SQL query.

[yvrprasad]

Not able to test/run this quickstart: camel-sql-binding

Tried Magesh's fix - Did not work

Tried mvn -Dmaven.test.skip=true jboss-as:deploy - Did not work

[ERROR] Failed to execute goal org.jboss.as.plugins:jboss-as-maven-plugin:7.5.Final:deploy (default-cli) on project switchyard-camel-sql-binding: Deployment failed and was rolled back. -> [Help 1]