就像这里提到的，我们在使用neo4j-ogm和ogm-bolt-driver(3.2.27)的java项目(playframework)中遇到了几乎相同的问题。连接有时会重置，抛出异常并与下一个请求重新连接(大多数情况下)。节点将通过存储库和neo4j-ogm会话从数据库中查询(将为小块工作打开)。
如有任何建议，我将不胜感激。
play.api.UnexpectedException: Unexpected exception[ConnectionException: Connection to the database failed]
at play.api.http.HttpErrorHandlerExceptions$.throwableToUsefulException(HttpErrorHandler.scala:358)
at play.api.http.DefaultHttpErrorHandler.onServerError(HttpErrorHandler.scala:264)
at play.core.server.AkkaHttpServer$$anonfun$2.applyOrElse(AkkaHttpServer.scala:430)
at play.core.server.AkkaHttpServer$$anonfun$2.applyOrElse(AkkaHttpServer.scala:422)
at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:454)
at akka.dispatch.BatchingExecutor$AbstractBatch.processBatch(BatchingExecutor.scala:63)
at akka.dispatch.BatchingExecutor$BlockableBatch.$anonfun$run$1(BatchingExecutor.scala:100)
at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18)
at scala.concurrent.BlockContext$.withBlockContext(BlockContext.scala:94)
at akka.dispatch.BatchingExecutor$BlockableBatch.run(BatchingExecutor.scala:100)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:49)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(ForkJoinExecutorConfigurator.scala:48)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1016)
at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1665)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1598)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:183)
Caused by: org.neo4j.ogm.exception.ConnectionException: Connection to the database failed
at org.neo4j.ogm.drivers.bolt.driver.BoltDriverExceptionTranslator.translateExceptionIfPossible(BoltDriverExceptionTranslator.java:38)
at org.neo4j.ogm.session.Neo4jSession.doInTransaction(Neo4jSession.java:601)
at org.neo4j.ogm.session.Neo4jSession.doInTransaction(Neo4jSession.java:558)
at org.neo4j.ogm.session.delegates.LoadOneDelegate.load(LoadOneDelegate.java:87)
at org.neo4j.ogm.session.delegates.LoadOneDelegate.load(LoadOneDelegate.java:53)
at org.neo4j.ogm.session.Neo4jSession.load(Neo4jSession.java:178)
at modules.shared.repositories.CrudRepository.find(CrudRepository.java:50)
at config.secured.Secured.getUserFromSession(Secured.java:88)
at config.secured.Secured.getUser(Secured.java:56)
at config.secured.Secured.getUser(Secured.java:39)
at config.secured.DataWizardSecurity$AuthenticatedAction.call(DataWizardSecurity.java:63)
at config.filter.SafeFormFactoryToRequest.call(SafeFormFactoryToRequest.java:24)
at config.filter.Messaged.call(Messaged.java:29)
at play.core.j.JavaAction.$anonfun$apply$8(JavaAction.scala:175)
at scala.concurrent.Future$.$anonfun$apply$1(Future.scala:672)
at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:431)
at play.core.j.HttpExecutionContext.$anonfun$execute$1(HttpExecutionContext.scala:64)
at play.api.libs.streams.Execution$trampoline$.execute(Execution.scala:70)
at play.core.j.HttpExecutionContext.execute(HttpExecutionContext.scala:59)
at scala.concurrent.impl.Promise$Transformation.submitWithValue(Promise.scala:393)
at scala.concurrent.impl.Promise$DefaultPromise.submitWithValue(Promise.scala:302)
at scala.concurrent.impl.Promise$DefaultPromise.dispatchOrAddCallbacks(Promise.scala:276)
at scala.concurrent.impl.Promise$DefaultPromise.map(Promise.scala:146)
at scala.concurrent.Future$.apply(Future.scala:672)
at play.core.j.JavaAction.apply(JavaAction.scala:176)
at play.api.mvc.Action.$anonfun$apply$4(Action.scala:82)
at play.api.libs.streams.StrictAccumulator.$anonfun$mapFuture$4(Accumulator.scala:168)
at scala.util.Try$.apply(Try.scala:210)
at play.api.libs.streams.StrictAccumulator.$anonfun$mapFuture$3(Accumulator.scala:168)
at scala.Function1.$anonfun$andThen$1(Function1.scala:85)
at scala.Function1.$anonfun$andThen$1(Function1.scala:85)
at scala.Function1.$anonfun$andThen$1(Function1.scala:85)
at scala.Function1.$anonfun$andThen$1(Function1.scala:85)
at scala.Function1.$anonfun$andThen$1(Function1.scala:85)
at play.api.libs.streams.StrictAccumulator.run(Accumulator.scala:199)
at play.core.server.AkkaHttpServer.$anonfun$runAction$4(AkkaHttpServer.scala:417)
at akka.http.scaladsl.util.FastFuture$.strictTransform$1(FastFuture.scala:41)
at akka.http.scaladsl.util.FastFuture$.$anonfun$transformWith$3(FastFuture.scala:51)
at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:448)
... 12 common frames omitted
Caused by: org.neo4j.driver.exceptions.ServiceUnavailableException: Connection to the database failed
at org.neo4j.driver.internal.util.Futures.blockingGet(Futures.java:143)
at org.neo4j.driver.internal.InternalSession.beginTransaction(InternalSession.java:98)
at org.neo4j.driver.internal.InternalSession.beginTransaction(InternalSession.java:92)
at org.neo4j.ogm.drivers.bolt.transaction.BoltTransaction.newOrExistingNativeTransaction(BoltTransaction.java:62)
at org.neo4j.ogm.drivers.bolt.transaction.BoltTransaction.<init>(BoltTransaction.java:50)
at org.neo4j.ogm.drivers.bolt.driver.BoltDriver.lambda$null$0(BoltDriver.java:128)
at org.neo4j.ogm.session.transaction.DefaultTransactionManager.openTransaction(DefaultTransactionManager.java:75)
at org.neo4j.ogm.session.Neo4jSession.beginTransaction(Neo4jSession.java:530)
at org.neo4j.ogm.session.Neo4jSession.doInTransaction(Neo4jSession.java:580)
... 49 common frames omitted
Suppressed: org.neo4j.driver.internal.util.ErrorUtil$InternalExceptionCause: null
at org.neo4j.driver.internal.async.inbound.ChannelErrorHandler.transformError(ChannelErrorHandler.java:127)
at org.neo4j.driver.internal.async.inbound.ChannelErrorHandler.fail(ChannelErrorHandler.java:113)
at org.neo4j.driver.internal.async.inbound.ChannelErrorHandler.exceptionCaught(ChannelErrorHandler.java:99)
at org.neo4j.driver.internal.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:302)
at org.neo4j.driver.internal.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:281)
at org.neo4j.driver.internal.shaded.io.netty.channel.AbstractChannelHandlerContext.fireExceptionCaught(AbstractChannelHandlerContext.java:273)
at org.neo4j.driver.internal.shaded.io.netty.channel.DefaultChannelPipeline$HeadContext.exceptionCaught(DefaultChannelPipeline.java:1377)
at org.neo4j.driver.internal.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:302)
at org.neo4j.driver.internal.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:281)
at org.neo4j.driver.internal.shaded.io.netty.channel.DefaultChannelPipeline.fireExceptionCaught(DefaultChannelPipeline.java:907)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.handleReadException(AbstractNioByteChannel.java:125)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:177)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
at org.neo4j.driver.internal.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
at org.neo4j.driver.internal.shaded.io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:832)
Caused by: java.net.SocketException: Connection reset
at java.base/sun.nio.ch.SocketChannelImpl.throwConnectionReset(SocketChannelImpl.java:345)
at java.base/sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:376)
at org.neo4j.driver.internal.shaded.io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:253)
at org.neo4j.driver.internal.shaded.io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1132)
at org.neo4j.driver.internal.shaded.io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:350)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:151)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
at org.neo4j.driver.internal.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
at org.neo4j.driver.internal.shaded.io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:832)
正如我在这里的回答中提到的，这个异常来自Neo4j Java Driver，可能有几个原因导致这种情况的发生。
例如，当驱动程序从空闲时间过长的内部连接池中获取连接时，可能会发生这种情况。一些云提供商限制负载平衡器的连接空闲时间。驱动程序可能会失败，只要它尝试使用这样的连接。
您可以启用连接活跃度检查来协助完成此操作。它确保在配置的超时时间内空闲的每个连接都进行短暂的网络交换。如果交换失败，则在提供另一个连接以供进一步的驱动程序使用之前选择或建立另一个连接。虽然这涉及到额外的网络交换，但它可能会防止驱动程序失败，从而导致更高级别的重试管理和潜在的指数级延迟。如果您希望测试每个连接，则可以将超时设置为零。
示例配置:
var config = Config.builder()
.withConnectionLivenessCheckTimeout( 60000, TimeUnit.MILLISECONDS )
.build();
var driver = GraphDatabase.driver( URL, AuthTokens, config );