The resource did not process correctly

org.springframework.data.mongodb.UncategorizedMongoDbException: Too many threads are already waiting for a connection. Max number of threads (maxWaitQueueSize) of 40 has been exceeded.; nested exception is com.mongodb.MongoWaitQueueFullException: Too many threads are already waiting for a connection. Max number of threads (maxWaitQueueSize) of 40 has been exceeded.
	at org.springframework.data.mongodb.core.MongoExceptionTranslator.translateExceptionIfPossible(MongoExceptionTranslator.java:96)
	at org.springframework.data.mongodb.core.MongoTemplate.potentiallyConvertRuntimeException(MongoTemplate.java:2002)
	at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:1885)
	at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:1696)
	at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:1679)
	at org.springframework.data.mongodb.core.MongoTemplate.find(MongoTemplate.java:598)
	at org.springframework.data.mongodb.core.MongoTemplate.find(MongoTemplate.java:589)
	at com.bitlv.site.dao.MongoBaseDao.find(MongoBaseDao.java:76)
	at com.bitlv.site.dao.CommonDaoImpl.query(CommonDaoImpl.java:18)
	at com.bitlv.site.service.SiteUriServiceImpl.findUri(SiteUriServiceImpl.java:28)
	at com.bitlv.site.web.decoder.SiteUrlDecoder.decode(SiteUrlDecoder.java:27)
	at com.bitlv.site.web.filter.UrlDecodeFilter.doFilter(UrlDecodeFilter.java:129)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:94)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:492)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1152)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1539)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1495)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:750)
Caused by: com.mongodb.MongoWaitQueueFullException: Too many threads are already waiting for a connection. Max number of threads (maxWaitQueueSize) of 40 has been exceeded.
	at com.mongodb.connection.DefaultConnectionPool.createWaitQueueFullException(DefaultConnectionPool.java:276)
	at com.mongodb.connection.DefaultConnectionPool.get(DefaultConnectionPool.java:95)
	at com.mongodb.connection.DefaultConnectionPool.get(DefaultConnectionPool.java:88)
	at com.mongodb.connection.DefaultServer.getConnection(DefaultServer.java:86)
	at com.mongodb.binding.ClusterBinding$ClusterBindingConnectionSource.getConnection(ClusterBinding.java:86)
	at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:429)
	at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:404)
	at com.mongodb.operation.FindOperation.execute(FindOperation.java:510)
	at com.mongodb.operation.FindOperation.execute(FindOperation.java:81)
	at com.mongodb.Mongo.execute(Mongo.java:836)
	at com.mongodb.Mongo$2.execute(Mongo.java:823)
	at com.mongodb.DBCursor.initializeCursor(DBCursor.java:870)
	at com.mongodb.DBCursor.hasNext(DBCursor.java:142)
	at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:1871)
	... 30 more