Generating derby properties on the fly can lead to non-deterministic engine 
startup behavior
--------------------------------------------------------------------------------------------

         Key: DERBY-1428
         URL: http://issues.apache.org/jira/browse/DERBY-1428
     Project: Derby
        Type: Bug

  Components: Store  
    Versions: 10.0.2.0, 10.0.2.1, 10.0.2.2, 10.1.1.0, 10.2.0.0, 10.1.2.1, 
10.1.3.0, 10.1.2.2, 10.1.2.3, 10.3.0.0, 10.1.2.4, 10.1.2.5, 10.1.4.0, 10.1.3.1  
  
    Reporter: Rick Hillegas


A Heisenbug can arise if more than one embedded Derby application runs in the 
same VM and at least one of them generates derby properties on the fly. Here's 
the problem scenario:

o The customer runs two embedded Derby apps in the same VM: EmbeddedApp and 
OtherApp.

o EmbeddedApp generates derby properties on the fly before connecting to a 
database and triggering engine startup.

o Whether the engine picks up those generated properties depends on whether 
EmbeddedApp or OtherApp runs first.

Here are two workarounds for the problem:

1) Don't generate derby properties on the fly. Instead, specify them on the VM 
startup command. Or specify them in a $DERBY_HOME/derby.properties file which 
is generated before the VM comes up and which does not change during the 
lifetime of the VM.

2) If you can't do (1), then modify the VM startup script so that it forces the 
applications to run in a deterministic order.


-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
   http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
   http://www.atlassian.com/software/jira

Reply via email to