Mercurial > hg > digilib
comparison doc/src/site/markdown/java-settings.md @ 1216:bd7dfa8b164e
move new digilib doc from https://it-dev.mpiwg-berlin.mpg.de/hg/digilib-doc into main repo.
| author | robcast |
|---|---|
| date | Fri, 06 Sep 2013 10:25:05 +0200 |
| parents | |
| children | 7a2de95a7b8e |
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| 1215:68625b3c5341 | 1216:bd7dfa8b164e |
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| 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` (or `setenbv.bat`) script with a line | |
| 13 | |
| 14 CATALINA_OPTS="-Xmx512m" | |
| 15 | |
| 16 in Tomcat's `bin` directory (giving 512MB RAM 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://localhost:8080/digilib/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://localhost:8080/digilib/server/dlConfig.jsp) | |
| 33 status page. | |
| 34 | |
| 35 Sometimes there are memory 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. In these cases it helped to install the JAI files in | |
| 38 Tomcats `lib/` directory or globally in the local Java JDK | |
| 39 installation (i.e. in the Java's 'jre/lib/ext/' directory on linux). | |
| 40 | |
| 41 # Sample setup | |
| 42 | |
| 43 The current digilib setup at the MPIWG (as of December 2010): | |
| 44 | |
| 45 * One frontend server running the lightweight web-multiplexer [pound](http://www.apsis.ch/pound/) | |
| 46 on port 80 that distributes requests to three servers runnning digilib | |
| 47 * the three servers run digilib under [Jetty](http://www.eclipse.org/jetty/) on port 8080 without Apache | |
| 48 * one server is the frontend server (Linux 32bit, Dual 2.4GHz Xeon, 2GB RAM) | |
| 49 * the other server is a separate, newer machine (Linux 64bit, Dual 1.8GHz Opteron, 2GB RAM) | |
| 50 * the third server is a separate, newer machine (Linux 32bit, Dual 2.8GHz Xeon, 4GB RAM) | |
| 51 * the digilib instances (digilib 2.0b1 as of 12.12.2011) run on Jetty 8.0.4 on Java | |
| 52 1.6.0_26 with 1GB of Java VM memory for digilib (-Xmx1024m) with JAI (1.1.3) and JAI-ImageIO (1.1) | |
| 53 installed in `Jetty/lib/ext` | |
| 54 * both digilib servers access all image files over NFS (over GBit Ethernet) from a central file server | |
| 55 (Solaris 10, Sun Fire 240, multiple RAIDs on Fibrechannel) |