<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> Eli Barzilay wrote at 05/21/2011 12:05 AM: <blockquote cite="mid:19927.14875.562426.85116@winooski.ccs.neu.edu" type="cite"> <pre wrap="">Switching to 3m sounds like the main improvement. Did you check the memory footprint? It can be especially bad with long-running server processes. (Specifically, there are certain data patterns that get CGC to leak very fast.) </pre> </blockquote> There was no perceptible leakage in earlier stress tests, and process size has been reasonable.  Perhaps because the app is external-DBMS-centric, I think it doesn't do anything in in-core data that I'd consider problematic for a GC, other than C interfacing.  There are large-ish acyclic lists with shared tails, and they seem to be collected reliably. Before we invested in moving to 3m at this point, we'd want some intuition that it is likely a reliability improvement for us.  For example, if we had information that gave us lesser confidence in CGC's *correctness*, other than the potential for leakage (which we can observe that we don't experience), that would be a good reason to move to 3m. Similar with PLT 4.2.5 vs. Racket 5.x: if we had information that in general the reliability of the code had improved, or that a nasty bug in 4.2.5 had been fixed, that would be a good reason to upgrade. Without that information, I think there is overriding incentive for this client to stick with known quantities for now.  Later, they might have resources to focus on the *non-reliability* reasons to upgrade. (My *personal* work has already moved to Racket 5.x, of course.) <blockquote cite="mid:19927.14875.562426.85116@winooski.ccs.neu.edu" type="cite"> <blockquote type="cite"> <pre wrap="">We have set up core dumps </pre> </blockquote> <pre wrap=""> A stack trace from such a dump can be very useful. </pre> </blockquote> Yes, I emphasized this as a top priority. :)  I was saddened to learn that, not only do core dumps seem to be disabled by default nowadays (we had to change 5 different things to get core reliably on their servers), but that Google suggests few people would be able to get core like this if they tried. Thanks for the input, Eli. <div class="moz-signature">-- <a class="moz-txt-link-freetext" href="http://www.neilvandyke.org/">http://www.neilvandyke.org/</a> </div> </body> </html>