Mercurial > hg > digilib-doc
comparison website/java-settings.md @ 6:96e83fba5eb7
more markdown docs.
| author | casties |
|---|---|
| date | Fri, 30 Aug 2013 19:00:19 +0200 |
| parents | |
| children |
comparison
equal
deleted
inserted
replaced
| 5:ee158994651f | 6:96e83fba5eb7 |
|---|---|
| 1 # Java VM settings for digilib | |
| 2 | |
| 3 The Java virtual machine (Java-VM) only uses a fixed amount of memory for | |
| 4 its operations. When an operation needs more memory than available it aborts | |
| 5 with an error ("out of memory error"). | |
| 6 | |
| 7 digilib can need a lot of memory depending on the size and type of images. | |
| 8 Since digilib runs as a servlet under Tomcat its in the same VM as the Tomcat | |
| 9 server. | |
| 10 | |
| 11 The amount of memory Tomcat (version 5.0) uses is configured by creating a | |
| 12 "setenv.sh" script with a line | |
| 13 | |
| 14 CATALINA_OPTS="-Xmx512m" | |
| 15 | |
| 16 in Tomcat's `bin` directory (giving 512MB in this case). | |
| 17 | |
| 18 You can check the amount of memory your digilib instance has available on the | |
| 19 bottom of the web page `/server/dlConfig.jsp` in your digilib instance (e.g. | |
| 20 [http://digilib.mpiwg-berlin.mpg.de/digitallibrary/server/dlConfig.jsp](http://digilib.mpiwg-berlin.mpg.de/digitallibrary/server/dlConfig.jsp)). | |
| 21 | |
| 22 # Installing JAI ImageIO | |
| 23 | |
| 24 In principle you should be able to install the | |
| 25 [Java Advanced Imaging](http://java.sun.com/javase/technologies/desktop/media/jai/) JAI-ImageIO | |
| 26 JAR file `jai_imageio.jar` (and native | |
| 27 library files if available) in the `/WEB-INF/lib/` directory of the | |
| 28 digilib web application as part of the default installation. | |
| 29 | |
| 30 You can see if the Jai-ImageIO plugin is active by checking for the | |
| 31 availability of the TIFF image format under "Supported image types" on the | |
| 32 [`/server/dlConfig.jsp`](http://digilib.mpiwg-berlin.mpg.de/digitallibrary/server/dlConfig.jsp) | |
| 33 status page. | |
| 34 | |
| 35 But sometimes there are classloader issues. Newer versions of Tomcat refuse to load | |
| 36 the libraries and I found that in some cases digilib stopped reading TIFF files | |
| 37 after a period of running. | |
| 38 | |
| 39 In these cases it helped to install the JAI files in Tomcats `lib/` | |
| 40 directory or globally in the local Java JDK | |
| 41 installation (i.e. in the Java's 'jre/lib/ext/' directory on linux). | |
| 42 | |
| 43 # Sample setup | |
| 44 | |
| 45 The current digilib setup at the MPIWG (as of December 2010): | |
| 46 | |
| 47 * One frontend server running the lightweight web-multiplexer [pound](http://www.apsis.ch/pound/) | |
| 48 on port 80 that distributes requests to three servers runnning digilib | |
| 49 * the three servers run digilib under [Jetty](http://www.eclipse.org/jetty/) on port 8080 without Apache | |
| 50 | |
| 51 * one server is the frontend server (Linux 32bit, Dual | |
| 52 2.4GHz Xeon, 2GB RAM) | |
| 53 * the other server is a separate, newer machine (Linux 64bit, Dual 1.8GHz | |
| 54 Opteron, 2GB RAM) | |
| 55 * the third server is a separate, newer machine (Linux 32bit, Dual 2.8GHz | |
| 56 Xeon, 4GB RAM) | |
| 57 * the digilib instances (digilib 2.0b1 as of 12.12.2011) run on Jetty 8.0.4 on Java | |
| 58 1.6.0_26 with 1GB of [Java VM memory | |
| 59 for digilib](#vm_settings) (-Xmx1024m) with JAI (1.1.3) and JAI-ImageIO (1.1) [installed in the Jetty/lib/ext](#installing_jai)(!) | |
| 60 * both digilib servers access all image files over NFS (over GBit | |
| 61 Ethernet) from a central file server (Solaris 10, Sun Fire 240, multiple RAIDs | |
| 62 on Fibrechannel) |