From SMW+ A Semantic Web Enterprise Wiki
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For audience: Below is a collection of some frequently asked questions and their answers. These questions have been taken from the SMW+ Discussion Forum and they may help you out in some issues about SMW+.
Select the topic that is most fitting to your issue from the table of contents or search this page by pressing Ctrl + F key combination from your browser and entering a search term.
Please check this list before asking a new question in the discussion forum to so that we avoid having multiple threads on the same issues.
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SMW+ / Halo extension
Wiki Administration Tool: User already logged in message
A: Remove the file /usr/share/mediawiki/deployment/tools/webadmin/sessiondata/userloggedin to force webadmin to allow a login.
DataExplorer shows corrupt instance or property names for example for german umlauts or other special characters.
A: You probably use MediaWiki's binary mode. The implementation of the DataExplorer does not handle that properly. You may either:
- update to the latest release (at least SMWHalo 1.5.2 patchlevel 1)
- replace 'VARCHAR' by 'VARBINARY' manually in file extensions/SMWHalo/includes/SMW_SemanticStoreSQL.php
A: Add the line $wgMaxShellMemory = 524288; to the end of LocalSettings.php. This variable defines the memory limit, the defaut value is 100M, increasing it to 524288 (512MB) fixes the problem. Manual:$wgMaxShellMemory
The autocompletion feature does not work. It only shows proposals when no filter string is entered.
A: You are probably using table with text fields of type VARBINARY. This is actually not a text type and requires conversion. Add the following line to your LocalSettings.php file:
$smwghConvertColoumns="utf8";
I want to remove the pre-delivered content of SMW+. What do I have to do
A: You may download the file Smwplus151_empty.zip which includes the "EmptySMW+ Wiki.bat" to erase the database of an SMW+ installation and replaces it with an empty set of tables where no data has been added yet. Read this manual for more information
I believe that my SMW+ installation is too slow. How can I check this?
A: A wrong configuration or the unavailability of services is in most cases the reason for slow response times of an SMW+ installation. You should read this article that gives typical response times and explains how to achieve them: Help:Optimizing_response_times_1.5.6
A: Check if this article is populated: [[MediaWiki:Halomenu]]. If the article is populated then you must restart your memcached-service (read that in the installation manual of SMW+). If the article is empty then you have deleted it. Open the history of the article and restore it.
A: This behavior is due the "Compatibility View Settings" of Internet Explorer 8. This settings can be found in the "Tools"-menu. There is an option "Display intranet sites in Compatibility View". If this is checked and you installed SMW+ locally or in your intranet, the menu might not work. Uncheck this option and remove the URL of your installation from the "Websites in Compatibility View"-list above, if it's listed there. This prevents IE8 from behaving like IE7.
Triple store issues
When the TSC comes up, it fails with the following log message:
"395 10 Jan 2011 11:19:25 [main] ERROR com.ontoprise.smwplus.triplestore.TripleStoreConnector - java.io.FileNotFoundException: activemq-data/localhost/journal/data-control (No such file or directory)"
A: The TSC process does not have the access right to write in the directory where the TSC is installed. Make it writable (or disable the message broker with the option 'msgbroker=none')
The TSC fails with the following log message:
"7328 10 Jan 2011 15:29:13 [8520103@qtp-8915406-0] WARN org.apache.cxf.phase.PhaseInterceptorChain - Application {http://sparqlendpoint.triplestore.smwplus.ontoprise.com/}c has thrown exception, unwinding now org.apache.cxf.interceptor.Fault: javax/ws/rs/core/Response$StatusType"
A: This may have been caused by OpenJDK instead of Sun JDK/JRE installations. Actual cause is yet to be known. This problem seems get solved by replacing the REST interface library.
- Download lib/jsr311-api-1.1.1.jar
- Replace 'lib/jsr311-api-1.0.jar' with 'lib/jsr311-api-1.1.1.jar'
I'm using the wiki together with the TSC and my wiki contains umlauts (or other special characters) which are corrupted when requested via SPARQL or ASK.
A: You are probably using text fields of type VARBINARY. Add the following line to your LocalSettings.php:
$smwgSPARQLResultEncoding="UTF-8";
The Triple store connector(TSC) cannot access the wiki database during synchronization.
The log contains the following error message:
"[main] error com.ontoprise.smwplus.triplestore.sparulmapper.LoadCommand - java.lang.ClassNotFoundException: com.mysql jdb.driver"
A: The MySQL database connector driver is not delivered with the TSC due to license problems. You have to download it from here.
Extract the archive and copy the file 'mysql-connector-java-5.1.13-bin.jar' into the lib folder of the TSC. Otherwise the TSC will not have access to the MySQL database.
I want to access the Tiple store connector (TSC) with an external application. Is this possible
A: Yes, the TSC can be queried using the SPARQL protocol. Take a look at the RDF SPARQL protocol. The TSC uses the HTTP binding as described there. It can be updated using SPARUL (SPARQL/Update).
Both endpoint are located by default at localhost:8080/sparql and localhost:8080/sparul. You can access them with your preferred REST webservice API.
When I open the special page 'Special:TSA' it fails with the following error message:
"Unexpected non-MediaWiki exception encountered, of type "Exception" exception 'Exception' with message 'Could not connect to a broker' in E:\Ontoprise\SMWPLUS\htdocs\mediawiki\extensions\SMWHalo\includes\storage\stompclient\Stomp.php:217"
A: You probably do not use a messagebroker. This is the default setting of the TSC. Remove the following line from your LocalSettings.php:
$smwgMessageBroker = '<some IP or host>';
Initializing the Triple store fails with the following error message:
"Fatal error: Call to undefined method SMWARC2Store::initialize() in C:\xampp2\htdocs\EXPO\extensions\SMWHalo\specials\SMWTripleStoreAdmin\SMW_TripleStoreAdmin.php on line 33"
A: You are probably using an extension with another SPARQL endpoint like the RDFIO extension. Find and remove this extension.
I want to use generateTree together with the TSC. However, it does not work.
A: Make sure you specify the option useTsc=1 using this exact spelling - mind the lower and uppercase! For example "useTSC" will NOT work!
I try to add F-logic rules but it does not work.
A: F-Logic is only supported by TSC 1.5 and below. TripleStoreConnector 1.5.1 and later only supports ObjectLogic. When using Jena, you can also specify rules in Jena's rule language. If so, don't forget to add the attribute native="true" in your rule tag in this case.
I wish to use rules with the TripleStoreConnector basic, but it does not work for some reason.
A: You may have selected the wrong reasoner. Make sure you have reasoner=rule on your command line when you start the TSC.
SMW+ / Gardening extension
The Gardening log contains the statement: "No input file specified."
The Gardening bots do not work. When I click on "console log" left to the "Cancel bot" button, a prompt for downloading the index.php appears. The log contains the following statement: "No input file specified."
A: Make sure that the PHP path is correct and that it points to the PHP CLI executable and not on php-cgi.
Example:
$phpInterpreter="C:/php/php.exe";
Lucene index
I cannot create a Lucene index using rebuildIndexManually.bat
A: Check the following things:
- Is the MediaWiki dump created successfully?
- Are all the paths in rebuildIndexManually.bat valid?
- Do the files global.conf and lsearch.conf exist? Do they use valid paths and IPs?
Note that 'localhost' is not allowed and it cannot be used with the Lucene server. It has to be a real IP or hostname.
Lucene index creation fails with the following error message:
Got exit value 1 while executing [fsutil, hardlink, create,.... java.io.IOException: Error executing command.... makeIndexSnapshot..
A: You probably have insufficient rights when you rebuild the index. Change to administrator rights and try again. This usually happens on Windows Server 2008 and Windows 7.
Installing Halo extension
I am using patch.php to apply patches to my MediaWiki installation but I get errors.
- Example
php patch.php -d C:\Projekt SMW+\xampp\htdocs\mediawiki -p C:\Projekt SMW+\xampp\htdocs\mediawiki\extensions\SMWHalo\patch.txt
A: You have whitespaces in your path. In this case you have to quote the parameters:
- Example
php patch.php -d "C:\Projekt SMW+\xampp\htdocs\mediawiki" -p "C:\Projekt SMW+\xampp\htdocs\mediawiki\extensions\SMWHalo\patch.txt"
I get a blank page and nothing else
A: Mostly this happens if error reporting in PHP is suppressed. Please add the following two lines temporarily to your LocalSettings.php to activate error reporting and try again:
error_reporting(E_ALL);
ini_set("display_errors", 1);
Fatal error: Unsupported operand types
I get the following error message after installing SMWHalo:
Fatal error: Unsupported operand types in /path/SMW_Initialize.php on line 58
A: You either did not install Semantic MediaWiki or you included the call (require_once('extensions/SemanticMediaWiki/SemanticMediaWiki.php');) after the SMWHalo call in your LocalSettings.php file. You have to include it before SMWHalo.
MySQL returned error that a FUNCTION does not exist
After upgrading MySQL I get the following error message after installing SMWHalo:
MySQL returned error "1305: FUNCTION wikidb.JAROWINKLER does not exist"
A: Re-install the user defined MySQL functions:
1. Copy the file libhalowiki-mysql5.dll for MySQL 5.x (Windows) or libhalowiki-mysql5.so for MySQL 5.x (Linux) to a location that is accessible to the MySQL Server. For MySQL versions lower than 5.1.19, the bin and/or lib directories right beneath the MySQL installation directory should work. For MySQL version 5.1.19 and beyond, you are required to copy the dll to the plugin_dir. The plugin_dir can be determined by running the following query:
mysql> show variables like 'plugin_dir';
+---------------+-----------------------------+ | Variable_name | Value | +---------------+-----------------------------+ | plugin_dir | C:\MySQL Server 5.1.21\lib/ | +---------------+-----------------------------+
1 row in set (0.00 sec)
2. Connect to your mysql database using the GUI-tool (e.g. the query browser) or the command line interface and execute the following command: (replace the DLL's/shared object lib's name if necessary)
CREATE FUNCTION editdistance RETURNS INTEGER SONAME 'libhalowiki-mysql5.dll';
CREATE FUNCTION jarowinkler RETURNS REAL SONAME 'libhalowiki-mysql5.so';
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