Cannot unmarshall large session file: InvalidProtocolBufferException -------------------------------------------------------------------- Key: DROOLS-25 URL: https://issues.jboss.org/browse/DROOLS-25 Project: Drools Issue Type: Bug Security Level: Public(Everyone can see) Affects Versions: 5.5 Environment: Jdk 7 Reporter: Magnus Vojbacke Assignee: Edson Tirelli Fix For: 5.6, 6.0.0.Alpha1 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. Here's the stack trace: {code:title=Stacktrace} com.google.protobuf.InvalidProtocolBufferException: Protocol message was too large. May be malicious. Use CodedInputStream.setSizeLimit() to increase the size limit. at com.google.protobuf.InvalidProtocolBufferException.sizeLimitExceeded:89 at com.google.protobuf.CodedInputStream.refillBuffer:720 at com.google.protobuf.CodedInputStream.isAtEnd:666 at com.google.protobuf.CodedInputStream.readTag:99 at org.drools.marshalling.impl.ProtobufMessages$Header$Builder.mergeFrom:967 at org.drools.marshalling.impl.ProtobufMessages$Header$Builder.mergeFrom:773 at com.google.protobuf.AbstractMessageLite$Builder.mergeFrom:212 at com.google.protobuf.AbstractMessage$Builder.mergeFrom:746 at org.drools.marshalling.impl.ProtobufMessages$Header.parseFrom:724 at org.drools.marshalling.impl.PersisterHelper.readFromStreamWithHeader:234 at org.drools.marshalling.impl.ProtobufInputMarshaller.loadAndParseSession:217 at org.drools.marshalling.impl.ProtobufInputMarshaller.readSession:107 at org.drools.marshalling.impl.ProtobufMarshaller.unmarshall:143 {code} 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.