The broker is currently making use of the PooledByteBufferAllocator, which was not expected. The codebase in general (client/common/broker) makes many attempts to ensure that the SimpleByteBufferAllocator is used by default, however previous refactoring of the network layer has lead to a path in which the broker is able to start without engaging use of the SimpleByteBufferAllocator.
As a result, MINA is effectively able to overwrite existing frame payload in the broker at random before a given command is completed and frame payloads are combined in a new buffer. This can also lead to unexpected situations where a ByteBuffer attempts to add its contents to itself.
MINANetworkDriver should ensure it always sets use of the SimpleByteBufferAllocator.