Thanks for the info. I thought the Java serialization metadata would have been large compared to the relevant data, but I guess not!
On Oct 29, 5:42 pm, Kenton Varda <ken...@google.com> wrote: > It sounds plausible. There's no fundamental reason why protocol buffers > should be faster than Java serialization, at least for simple objects like > yours composed of a set of primitive values. Since Java serialization is > implemented by the VM, it can probably optimize better than protobufs can. > However, the protobuf wire format is considerably simpler, portable to many > languages other than Java, and handles extensibility better. Also, I > suspect you'll find that Java serialization gets slower with more complex > object trees. And finally, Java serialization involves sending a large > chunk of metadata over the wire, basically describing each class -- protocol > buffers avoids this by assuming that the receiver already knows the type > information. But when sending a giant homogeneous array of simple objects, > the metadata overhead ends up small. > > > > On Thu, Oct 29, 2009 at 1:45 PM, jta23 <jonathanhalc...@gmail.com> wrote: > > > I'm looking to get sense if my experience sounds reasonable or if it > > sounds like I'm doing something very wrong, any insight appreciated! > > > I have a Serializable Java object containing: > > > 4 integers > > 3 bytes > > 2 Strings > > 1 short > > 1 double > > > I have a vector of about 10M objects I am sending from a server to a > > client. The ObjectOutputStream for the server is created like this: > > > Socket clientSocket; > > ... > > outputStream = new ObjectOutputStream(clientSocket.getOutputStream()); > > > and the ObjectInputStream is created in a similar fashion. > > > I send the Serializable objects like this: > > > outputStream.writeObject(msg); > > > and receive them like this: > > > MyMessage msg = (MyMessage)inputStream.readObject(); > > > On my rather slow server I can receive and process about 12K messages > > a second. > > > Now for the Protocol Buffers part: > > I used protoc to create a new Java class using: > > 8 int32s > > 2 strings > > 1 double > > > I create objects like this: > > > MyProtoMessage.MyMessage msg = > > MyProtoMessage.MyMessage.newBuilder() > > ... > > .build(); > > > and send them like this: > > > byte size = (byte)msg.getSerializedSize(); > > outputStream.writeByte(size); > > outputStream.write(msg.toByteArray()); > > > and finally they are read like this: > > > byte size = inputStream.readByte(); > > byte []bytes = new byte[size]; > > inputStream.readFully(bytes); > > MyProtoMessage.MyMessage msg = MyProtoMessage.MyMessage.parseFrom > > (bytes); > > > With this protobuf approach I can do about 9K a second. I also tried > > writeDelimited/parseDelimited and it was even slower. > > > Does this sound reasonable? I expected it to be faster than the > > standard Java serialization approach. > > > Thanks! --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~----------~----~----~----~------~----~------~--~---
