My bad. To clarify the issue here... the problem manifests itself only on Solr 3.5 specifically when the example configuration is copied somewhere else (losing the relative path nature to the <lib> references). Generally this happens when folks want to deploy into Tomcat. In Solr 3.5, the VelocityResponseWriter was moved out of core and back to a contrib module. With this move, it became explicitly listed in the <lib> references by relative paths which are incorrect (not just for the VelocityResponseWriter but also for Solr Cell, Clustering, Data Import Handler, and the language identifier). All those other components are lazy loaded or not wired in by default so they don't cause a startup issue (but would not work!!!). The VelocityResponseWriter, however, is explicitly registered in the example configuration in solrconfig.xml as:
<queryResponseWriter name="velocity" class="solr.VelocityResponseWriter" enable="${solr.velocity.enabled:true}"/> To fix the startup issue, if you don't want or care about the /browse interface or any other custom use of the VelocityResponseWriter you can either remove that line from solrconfig.xml (and restart Solr), or set the system property solr.velocity.enabled to false (something like doing <export JAVA_OPTS="$JAVA_OPTS -Dsolr.velocity.enabled=false"> before launching Tomcat) or set that default value to false in solrconfig.xml. Note that if you do hit /browse after you've disabled the VelocityResponseWriter, you will get the standard Solr XML response returned as that is how Solr handles an unknown response writer parameter. If you do want the VelocityResponseWriter to work, you'll need to correct the <lib> references in solrconfig.xml to point to the appropriate locations. Apologies for this issue. I juggle Solr 3.x's and Solr trunk and various snapshots of trunk and I typically don't use Tomcat. I've reopened https://issues.apache.org/jira/browse/SOLR-2718 to get it backported to 3.x in time for a Solr 3.6 release. I'll tackle this in a couple of weeks. I'm also going to start a new solr-user thread about the VelocityResponseWriter and solicit folks opinions regarding its future. Erik On Dec 8, 2011, at 06:03 , Kissue Kissue wrote: > I just migrated to Solr 3.5 and whenever i start it up i get the error > below. Any ideas what might be wrong? Previously i didn't have to do > anything special to get it to work. HAs anything changed in solr 3.5? > > > 08-Dec-2011 10:45:03 org.apache.solr.common.SolrException log > SEVERE: org.apache.solr.common.SolrException: Error loading class > 'solr.VelocityResponseWriter' > at > org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:389) > at org.apache.solr.core.SolrCore.createInstance(SolrCore.java:425) > at > org.apache.solr.core.SolrCore.createInitInstance(SolrCore.java:447) > at org.apache.solr.core.SolrCore.initPlugins(SolrCore.java:1556) > at org.apache.solr.core.SolrCore.initPlugins(SolrCore.java:1550) > at org.apache.solr.core.SolrCore.initPlugins(SolrCore.java:1583) > at org.apache.solr.core.SolrCore.initWriters(SolrCore.java:1466) > at org.apache.solr.core.SolrCore.<init>(SolrCore.java:556) > at org.apache.solr.core.CoreContainer.create(CoreContainer.java:463) > at org.apache.solr.core.CoreContainer.load(CoreContainer.java:316) > at org.apache.solr.core.CoreContainer.load(CoreContainer.java:207) > at > org.apache.solr.core.CoreContainer$Initializer.initialize(CoreContainer.java:130) > at > org.apache.solr.servlet.SolrDispatchFilter.init(SolrDispatchFilter.java:94) > at > org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:295) > at > org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422) > at > org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115) > at > org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4001) > at > org.apache.catalina.core.StandardContext.start(StandardContext.java:4651) > at > org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791) > at > org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771) > at > org.apache.catalina.core.StandardHost.addChild(StandardHost.java:546) > at > org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:637) > at > org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:563) > at > org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:498) > at > org.apache.catalina.startup.HostConfig.start(HostConfig.java:1277) > at > org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:321) > at > org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) > at > org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) > at > org.apache.catalina.core.StandardHost.start(StandardHost.java:785) > at > org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) > at > org.apache.catalina.core.StandardEngine.start(StandardEngine.java:445) > at > org.apache.catalina.core.StandardService.start(StandardService.java:519) > at > org.apache.catalina.core.StandardServer.start(StandardServer.java:710) > at org.apache.catalina.startup.Catalina.start(Catalina.java:581) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > at java.lang.reflect.Method.invoke(Method.java:597) > at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) > at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414) > Caused by: java.lang.ClassNotFoundException: solr.VelocityResponseWriter > at java.net.URLClassLoader$1.run(URLClassLoader.java:200) > at java.security.AccessController.doPrivileged(Native Method) > at java.net.URLClassLoader.findClass(URLClassLoader.java:188) > at java.lang.ClassLoader.loadClass(ClassLoader.java:303) > at java.net.FactoryURLClassLoader.loadClass(URLClassLoader.java:592) > at java.lang.ClassLoader.loadClass(ClassLoader.java:248) > at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:316) > at java.lang.Class.forName0(Native Method) > at java.lang.Class.forName(Class.java:247) > at > org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:373) > ... 39 more