Subject: C423 JGSI Review Resent-Date: Thu, 30 Sep 1999 23:13:27 -0400 Resent-From: Geoffrey Fox Resent-To: p_gcf@npac.syr.edu Date: Fri, 10 Sep 1999 07:55:16 +0200 From: Michael Philippsen To: Geoffrey Fox CC: phlipp@ira.uka.de Title: Jaguar: Enabling Efficient Communication and I/O in Java Authors:Matt Welsh and David Culler a)Overall Recommendation ------------------------ ACCEPT b)Words suitable for authors ---------------------------- This is a fine paper. However, I'm slightly disappointed by section 5 (preserialized objects) Apart from buffer handling the most serious performance problems of serialization are (a) the encoding of type information to handle both transparent class loading and the subtype problem mentioned below, (b) cycle detection for arbitrary graphs of objects, and (c) the ability to ship any objects (even those unknown at compile time) As far as I understand it, preserialized objects avoid all those problems (or significant portions of it). It is therefore slightly exaggerated to call the mechanism "serialization". I strongly suggest that the authors try to stress the fact that this is a very special & restricted form of serialization. Moreover, section 5.2 should discuss the limitations in more detail. Some minor remarks: ------------------- - In figure 1 I would like to see the numbers formatted in a way so that the .s are lined up. Like: .985 us 1.31 us 1706.0 us Similar for figures 7 and 9. - In section 4.3 I would like to see measurements instead of estimates for bandwidth over JNI. - section 5.2: since you don't have any form of type information in the preserialized objects, I don't see how object graphs of type T can be handled where the nodes can be arbitrary subtypes of T. Either discuss or mention limitations in 5.2 - I cannot understand the second paragraph of section 5.2 - Insert white space: 4th line from bottom of column that holds Fig 7. "offset.Next" 1st line of 2nd column that holds Fig 9. "timings(from" - 4th line of Acknowledgements: remove "design." References: ----------- updated versions of [3] and [22] will appear in the same issue. Please cite the journal article instead. [2] Self instead of self [3],[7],[8],[12],[17],[19],[22],[24],[25],[29] Java instead of java [4] Myrinet instead of myrinet [8] and [24] no URLs or URLs for both [13] HotSpot instead of hotspot [19] JIT instead of jit [22] RMI instead of rmi [25] PVM instead of pvm [28] Berkeley JAWS instead of berkeley jaws [28] avoid linebreak (-) in URL