Description of problem:

We are running BRMS version 5.3.1.BRMS-P05-temporary-patch. When attempting to load a stateful knowledge session, a "com.google.protobuf.InvalidProtocolBufferException" exception is thrown in BRMS5.3.1+Roll Up 5 applied, with the message "Protocol message was too large.  May be malicious.  Use CodedInputStream.setSizeLimit() to increase the size limit.".

According to DROOLS-25:

When trying to unmarshall a large knowledge session from a file stream, an exception is thrown.

It seems that there is a default message size limit in Protobuf (used by Drools marshalling). Apparently, what happens is that the marshalled "Header" message exceeds this size, which causes Protobuf to throw this exception.

I suspect that the Header field "payload" is the culprit, since it seems to contain the rest of the knowledge base in byte array form.

Suggested solutions:

#1
You can set the size limit of the Protobuf CodedInputStream, but there doesn't seem to be any way of providing this parameter to the Drools unmarshalling API.

#2
When you unmarshall from a byte array, Protobuf does not enforce any message size limit. I have successfully implemented a patch in drools-core that preloads the file into memory and unmarshalls from a byte array. Probably the least desirable fix.



Version-Release number of selected component (if applicable):
BRMS 5.3.1 last roll up patch applied (5)



Steps to Reproduce:
Please see steps to reproduce in https://issues.jboss.org/browse/DROOLS-25.