Both the VdbSequencer (VS) and DynamicVdbSequencer (DVS) get binary values from their input property, eg.

final Binary binaryValue = inputProperty.getBinary();

• The VS creates a ZipInputStream from the binaryValue - this is closed upon completion;
• The DVS creates an InputStream - this is NOT closed upon completion.

• The new stream is passed into VdbSequencer.readManifest();
• The stream is then passed into VdbManifest.read();
• VdbManifest has its own reader and the stream is passed into Reader.read();
• Reader.read() opens an XMLStreamReader instance but this is NOT closed upon completion;

The creation of the XMLStreamReader creates a NamedLock on the original binaryValue of the inputProperty. Since the XMLStreamReader is not closed, this lock is never cleared.

The saving of a session also creates the same named NamedLock and since one already exists and is locking the binaryValue, deadlock occurs and Modeshape hangs.

This has been observed in unit tests where

• the Vdb Sequencer is executed;
• a different session clears the repository (hence modifying the binaryValue property);
• the clear-session is saved.

Hopefully, PR to follow with fix, closing the sequencer streams.