昨天把博客上线，今天早上起来发现昨天晚上Solr服务器出错了，到今天下午才有时间来解决，一个Tomcat放博客项目，另一个Tomcat放Solr服务器，配置了多个Solr Core，第一次重启Solr服务器所在的Tomcat，报错信息如下。
-05-18 14:06:01.173 ERROR (coreContainerWorkExecutor-2-thread-1) [ ] o.a.s.c.CoreContainer Error waiting for SolrCore to be created
java.util.concurrent.ExecutionException: org.mon.SolrException: Unable to create core [resource_core]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.solr.core.CoreContainer.lambda$load$14(CoreContainer.java:671)
at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at org.mon.util.ExecutorUtil$MDCAwareThreadPoolExecutor.lambda$execute$0(ExecutorUtil.java:188)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.mon.SolrException: Unable to create core [resource_core]
at org.apache.solr.core.CoreContainer.createFromDescriptor(CoreContainer.java:1053)
at org.apache.solr.core.CoreContainer.lambda$load$13(CoreContainer.java:642)
at com.codahale.metrics.InstrumentedExecutorService$InstrumentedCallable.call(InstrumentedExecutorService.java:197)
... 5 more
Caused by: org.mon.SolrException
at org.apache.solr.core.SolrCore.(SolrCore.java:1008)
at org.apache.solr.core.SolrCore.(SolrCore.java:863)
at org.apache.solr.core.CoreContainer.createFromDescriptor(CoreContainer.java:1037)
... 7 more
Caused by: java.nio.channels.OverlappingFileLockException
at sun.nio.ch.SharedFileLockTable.checkList(FileLockTable.java:255)
at sun.nio.ch.SharedFileLockTable.add(FileLockTable.java:152)
at sun.nio.ch.FileChannelImpl.tryLock(FileChannelImpl.java:1108)
at java.nio.channels.FileChannel.tryLock(FileChannel.java:1155)
at org.apache.lucene.store.NativeFSLockFactory.obtainFSLock(NativeFSLockFactory.java:126)
at org.apache.lucene.store.FSLockFactory.obtainLock(FSLockFactory.java:41)
at org.apache.lucene.store.BaseDirectory.obtainLock(BaseDirectory.java:45)
at org.apache.lucene.store.FilterDirectory.obtainLock(FilterDirectory.java:104)
at org.apache.solr.core.SolrCore.isWriterLocked(SolrCore.java:720)
at org.apache.solr.core.SolrCore.initIndex(SolrCore.java:742)
at org.apache.solr.core.SolrCore.(SolrCore.java:954)
... 9 more
看到了一个OverlappingFileLockException，于是在网上找各种Lunece锁机制，Solr锁什么的，然后就是在core中修改solrconfig.xml文件，网上有看到在solrconfig.xml中前面配置true，配置了但是没用，于是我把${solr.lock.type:native}修改成${solr.lock.type:simple}，报错的信息不一样了。
-05-18 15:08:31.112 ERROR (coreContainerWorkExecutor-2-thread-1) [ ] o.a.s.c.CoreContainer Error waiting for SolrCore to be created
java.util.concurrent.ExecutionException: org.mon.SolrException: Unable to create core [resource_core]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.solr.core.CoreContainer.lambda$load$14(CoreContainer.java:671)
at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at org.mon.util.ExecutorUtil$MDCAwareThreadPoolExecutor.lambda$execute$0(ExecutorUtil.java:188)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.mon.SolrException: Unable to create core [resource_core]
at org.apache.solr.core.CoreContainer.createFromDescriptor(CoreContainer.java:1053)
at org.apache.solr.core.CoreContainer.lambda$load$13(CoreContainer.java:642)
at com.codahale.metrics.InstrumentedExecutorService$InstrumentedCallable.call(InstrumentedExecutorService.java:197)
... 5 more
Caused by: org.mon.SolrException: Index dir '/opt/solr-home/resource_core/data/index/' of core 'resource_core' is already locked. The most likely cause is another Solr server (or another solr core in this server) also configured to use this directory; other possible causes may be specific to lockType: simple
at org.apache.solr.core.SolrCore.(SolrCore.java:1008)
at org.apache.solr.core.SolrCore.(SolrCore.java:863)
at org.apache.solr.core.CoreContainer.createFromDescriptor(CoreContainer.java:1037)
... 7 more
Caused by: org.apache.lucene.store.LockObtainFailedException: Index dir '/opt/solr-home/resource_core/data/index/' of core 'resource_core' is already locked. The most likely cause is another Solr server (or another solr core in this server) also configured to use this directory; other possible causes may be specific to lockType: simple
at org.apache.solr.core.SolrCore.initIndex(SolrCore.java:745)
at org.apache.solr.core.SolrCore.(SolrCore.java:954)
... 9 more
我看到索引文件目录被锁了，提示是可能另一个Solr服务器也在使用这个目录，但是我的项目只有一个Solr服务器啊，于是重启Tomcat，看日志，结果发现Tomcat把Solr启动了两次，索引文件被锁的原因出来了，但是为什么Tomcat会将Solr启动两次呢，结果就是我配置了Tomcat的虚拟路径。
prefix="localhost_access_log" suffix=".txt"
pattern="%h %l %u %t "%r" %s %b" />
参考https://blog..net/u011081244/article/details/6242才知道原因为什么会启动两次。
参考/article/48206aeaf9422e216ad6b39b.html将项目放在webapps目录之外，然后再配置server.xml，重启Tomcat之后就正常了。
prefix="localhost_access_log" suffix=".txt"
pattern="%h %l %u %t "%r" %s %b" />
