It may have something to do with SOLR-3425, but I'm not that sure it fits. I made some more tests.
Case 1 : with SolrCloud I can create a new core on one of the server by the admin GUI or by CREATE directive in URL. The data folder is created (but no conf folder, I believe zk conf is used). However ./solr/solr.xml is not updated with the new core parameter. If I restart the server, the core is lost (but data folder is kept) Case 2 : on a single solr server Creation of new core fails by the gui with error : GRAVE: org.apache.solr.common.SolrException: Error executing default implementation of CREATE at org.apache.solr.handler.admin.CoreAdminHandler.handleCreateAction(CoreAdminHandler.java:396) at org.apache.solr.handler.admin.CoreAdminHandler.handleRequestBody(CoreAdminHandler.java:141) at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:129) at org.apache.solr.servlet.SolrDispatchFilter.handleAdminRequest(SolrDispatchFilter.java:359) at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:175) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1337) at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:484) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119) at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524) at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:233) at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1065) at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:413) at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:192) at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:999) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117) at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:250) at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:149) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111) at org.eclipse.jetty.server.Server.handle(Server.java:351) at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:454) at org.eclipse.jetty.server.BlockingHttpConnection.handleRequest(BlockingHttpConnection.java:47) at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:890) at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:944) at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:634) at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:230) at org.eclipse.jetty.server.BlockingHttpConnection.handle(BlockingHttpConnection.java:66) at org.eclipse.jetty.server.bio.SocketConnector$ConnectorEndPoint.run(SocketConnector.java:254) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:599) at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:534) at java.lang.Thread.run(Unknown Source) Caused by: java.lang.RuntimeException: Can't find resource 'solrconfig.xml' in classpath or 'solr\core2\conf/', cwd=F:\solr-4.0\Test at org.apache.solr.core.SolrResourceLoader.openResource(SolrResourceLoader.java:294) at org.apache.solr.core.SolrResourceLoader.openConfig(SolrResourceLoader.java:260) at org.apache.solr.core.Config.<init>(Config.java:111) at org.apache.solr.core.Config.<init>(Config.java:78) at org.apache.solr.core.SolrConfig.<init>(SolrConfig.java:117) at org.apache.solr.core.CoreContainer.create(CoreContainer.java:742) at org.apache.solr.handler.admin.CoreAdminHandler.handleCreateAction(CoreAdminHandler.java:391) ... 29 more Using an URL CREATE and giving relative pathes for solrconfig.xml and shema.xml fails later on stopwords.txt Again solr/solr.xml is not updated, but the runtime exception could explain that in this case. Pierre -----Message d'origine----- De : Pierre GOSSÉ [mailto:pierre.go...@arisem.com] Envoyé : mercredi 1 août 2012 16:22 À : solr-user@lucene.apache.org Objet : Cloud and cores Hi all, I'm playing around with SolrCloud and followed indications I found at http://wiki.apache.org/solr/SolrCloud/ - Started Instance 1 with embedded zk - Started Instances 2 3 and 4 using Instance 1 as zk server. Everything works fine. Then, using CoreAdmin, I add a second core in collection1 for Instance 1 and 3 ... everything is ok in the admin GUI, meaning that the graph show 2 shards of 3 server addresses each, those having 2 cores showing to time on the graph. collection1 shard1 wks-pge:7574 wks-pge:8900 wks-pge:8983 shard2 wks-pge:8983 wks-pge:7500 wks-pge:8900 On instances 1 and 3 I have 2 cores both at the bottom of the left column, and in the CoreAdmin screen. I restart everything, and find the server in what seems to be an inconsistent state : i.e. graph still showing 2 shards of 3 server addresses, but CoreAdmin not showing my additional cores any more. Is there a problem in SolrCloud or CoreAdmin, or did I just do something stupid here ? :) Pierre