Summary

Confluence XML-RPC function getBlogEntry does not always return the full exception message if the ID requested is a page

Environment

• Confluence 5.10+

Steps to Reproduce

1. Install Confluence
2. Enable XML-RPC from Administration -> Further Configuration
3. Send multiple requests for getBlogEntry

Expected Results

Every time Confluence will reply with the below error

<Fault 0: 'java.lang.Exception: java.lang.ClassCastException: com.atlassian.confluence.pages.Page cannot be cast to com.atlassian.confluence.pages.BlogPost'>

Actual Results

After multiple attempts, the returned error looks like this:

<?xml version="1.0"?><methodResponse><fault><value><struct><member><name>faultString</name><value>java.lang.Exception: java.lang.ClassCastException</value></member><member><name>faultCode</name><value><int>0</int></value></member></struct></value></fault></methodResponse>

Note the difference:
java.lang.Exception: java.lang.ClassCastException
java.lang.Exception: java.lang.ClassCastException: com.atlassian.confluence.pages.Page cannot be cast to com.atlassian.confluence.pages.BlogPost

Workaround

• The problem on the Confluence side is caused due to JVM does JIT optimisation and suppresses stack-trace for frequent errors.
• Restart of the Confluence temporary solves the problem.
• Disable JIT optimization in Confluence, add to JVM parameter:

  -XX:-OmitStackTraceInFastThrow