[Bug 1211110] Re: network manager openvpn dns push data not updating resolv.conf
Would love to see this feature to make a very popular VPN client work seamlessly with Ubuntu. I'm on 14.04 and trying to figure out a work- around for this (probably will disable resolvconf). -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to openvpn in Ubuntu. https://bugs.launchpad.net/bugs/120 Title: network manager openvpn dns push data not updating resolv.conf To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/120/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 568823] Re: Improved Java Memory/Performance Defaults
An additional possibility is to specify the JVM using the -server flag. Although Java also will auto-set this based on the machine class, currently it will only choose the server JVM one machines with 2GB+ of RAM and 2 cores. Interestingly, the 32bit instances offered by EC2 (a popular choice for hosting web frontends) have 1.7GB of RAM, which would cause the client VM to be auto-selected. http://java.sun.com/docs/hotspot/HotSpotFAQ.html#compiler_types http://java.sun.com/j2se/1.5.0/docs/guide/vm/server-class.html -- Improved Java Memory/Performance Defaults https://bugs.launchpad.net/bugs/568823 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to tomcat6 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 568823] [NEW] Improved Java Memory/Performance Defaults
Public bug reported: Binary package hint: tomcat6 Forking an issue from #541520 The current default of a 128MB heap does not make sense. This was chosen when Java 1.4 had a default maximum heap size of 64MB. In Java 1.5 and later, the JVM will automatically size the heap based on available memory. So the current default setting actually unnecessarily sets a limit on the memory available to tomcat, when not setting anything at all would actually allow the modern JVMs to do a better job. References: http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html#par_gc.ergonomics.default_size http://java.sun.com/javase/6/docs/technotes/guides/vm/gc-ergonomics.html http://java.sun.com/docs/hotspot/gc5.0/ergo5.html *** initial heap size: Larger of 1/64th of the machine's physical memory on the machine or some reasonable minimum. Before J2SE 5.0, the default initial heap size was a reasonable minimum, which varies by platform. You can override this default using the -Xms command-line option. maximum heap size: Smaller of 1/4th of the physical memory or 1GB. Before J2SE 5.0, the default maximum heap size was 64MB. You can override this default using the -Xmx command-line option. *** ** Affects: tomcat6 (Ubuntu) Importance: Undecided Status: New -- Improved Java Memory/Performance Defaults https://bugs.launchpad.net/bugs/568823 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to tomcat6 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 568823] Re: Improved Java Memory/Performance Defaults
Attaching proposed patch. ** Patch added: tomcat6.mem.diff http://launchpadlibrarian.net/45066613/tomcat6.mem.diff -- Improved Java Memory/Performance Defaults https://bugs.launchpad.net/bugs/568823 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to tomcat6 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 541520] Re: Using incorrect JVM Garbage Collector
Done (#568823). As I say I'm still not convinced about the CMS collector as a default, but I'll follow up later if I become more passionate about it. :) -- Using incorrect JVM Garbage Collector https://bugs.launchpad.net/bugs/541520 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to tomcat6 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 541520] Re: Using incorrect JVM Garbage Collector
The point that we know something the JVM can't know, eg, that this JVM is running a web server, is fair. I'm still not convinced that specifying the CMS collector is the right application of this knowledge, and I'm new to Ubuntu (from a contributor standpoint, anyway) so I don't know what the project goals are for the default configuration. But for now let me move down what I hope is a fruitful path. It sounds like (and please correct me if I'm wrong) we want to choose settings that: 1) at a minimum, work (eg, after running apt-get, tomcat actually boots up and serves requests) 2) has reasonable defaults to suit the sort of hardware we expect people to run web servers on Currently our defaults are: -Xmx128M -XX:+UseConcMarkSweepGC Which satisfies #1, but I still think is not great for #2. Maybe as you alluded we'd do better by not specifying the maximum heap size? The rationale was that 64MB is not usually enough, and that made sense under JDK1.4, when this was the default heap size. However it looks like in 1.5 and later, the heap selection was changed to be based on the amount of available RAM *** initial heap size: Larger of 1/64th of the machine's physical memory on the machine or some reasonable minimum. Before J2SE 5.0, the default initial heap size was a reasonable minimum, which varies by platform. You can override this default using the -Xms command-line option. maximum heap size: Smaller of 1/4th of the physical memory or 1GB. Before J2SE 5.0, the default maximum heap size was 64MB. You can override this default using the -Xmx command-line option. *** So if we don't give any heap parameters to the JVM: - The heap will be at least 128MB (satisfy goal #1) on any machine with 512MB or more of RAM - The JVM is free to choose a heap much larger than 128MB, based on the available memory (satisfy goal #2) For this reason I'd suggest we remove the -Xmx128M portion from the command line. References: http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html#par_gc.ergonomics.default_size http://java.sun.com/javase/6/docs/technotes/guides/vm/gc-ergonomics.html http://java.sun.com/docs/hotspot/gc5.0/ergo5.html -- Using incorrect JVM Garbage Collector https://bugs.launchpad.net/bugs/541520 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to tomcat6 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 541520] Re: Using incorrect JVM Garbage Collector
Folks -- sorry for chiming in here after the train has apparently left the station :) I've been working on optimizing my Tomcat configuration for the past couple days, and this optimization has mostly centered around the garbage collector. I'm concerned that specifying the CMS collector is classic premature optimization. If I absorbed this change, my application performance would have gotten suddenly worse. But let's not talk about my specific case. To excerpt from the same whitepaper referenced above (section 6, first paragraph): Thus, the initial recommendation for selecting and configuring a garbage collector is to do nothing! That is, do not specify usage of a particular garbage collector, etc. Let the system make automatic choices based on the platform and operating system on which your application is running. As this implies, the Hotspot JVM will actually select a collector for you based on the system resources. Further, Sun's GC tuning document found at http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html#available_collectors.selecting Advises that heap size should actually be the first knob you adjust before switching collectors. I'm all for choosing smart defaults. But I think in this case the advice from the guys who make Java is pretty clear. Let the JVM decide, and if it's not good enough, only then optimize for the metrics you care about, and do not begin by choosing a specific collector. -- Using incorrect JVM Garbage Collector https://bugs.launchpad.net/bugs/541520 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to tomcat6 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
