"Connection refused" could also mean that you're not connecting using the correct bind address or you have a firewall or something blocking the connection.
You can see what ports your services are listening on with `sudo netstat -tlnp` If your machine's hostname is "mymachine" and you're trying to connect to "mymachine:8020", but it's listening on "127.0.0.1:8020", it might not work. On systems like Fedora/RHEL that use SSSD, I've had some luck putting "myhostname" as one of the targets for "hosts:" in /etc/nsswitch.conf, ahead of the other options, so that way the localhost name lookup prefers the local host name, rather than go to DNS. But, getting the nameservice configuration on your machine, the `hostname` output in the scripts, and the bind address for the server in the Java code, to all agree on the host name can be tricky. On Thu, Jul 8, 2021 at 10:49 AM Christine Buss <[email protected]> wrote: > > > ok Namenode is running. > > christine@centauri:~$ jps > 42753 NameNode > 42884 DataNode > 44438 NodeManager > 45002 Jps > 43116 SecondaryNameNode > 7629 QuorumPeerMain > 44301 ResourceManager > > I deleted everything and reinstalled again. > But accumulo init still gives me the connection refused Error. > Any other ideas? > Gesendet: Mittwoch, 07. Juli 2021 um 17:59 Uhr > Von: "Brian Loss" <[email protected]> > An: [email protected] > Betreff: Re: Hadoop ConnectException > Based on the jps output below, it would appear that no NameNode process is > running (only SecondaryNameNode). That would mean the name node process > exited for some reason. Check its logs and see if there is any useful error > message there. > > > On Jul 7, 2021, at 11:45 AM, <[email protected]> <[email protected]> wrote: > > Did you verify that Hadoop is really up and healthy? Look at the Hadoop > monitor pages and confirm that you can use the Hadoop cli to navigate around? > You may also need to update the accumulo configuration files / env to match > your configuration. > > You might what to look at using https://github.com/apache/fluo-uno as a quick > way to stand up an instance for testing – and that might give to additional > insights. > > From: Christine Buss <[email protected]> > Sent: Wednesday, July 7, 2021 11:21 AM > To: [email protected] > Subject: Hadoop ConnectException > > Hi, > > I am using: > Java 11 > Ubuntu 20.04.2 > Hadoop 3.3.1 > Zookeeper 3.7.0 > Accumulo 2.0.1 > > > I followed the instructions here: > https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-common/SingleCluster.html > and edited etc/hadoop/hadoop-env.sh, etc/hadoop/core-site.xml, > etc/hadoop/hdfs-site.xml accordingly. > 'ssh localhost' works without a passphrase. > > Then I started Zookeper, start-dfs.sh and start-yarn.sh: > christine@centauri:~$ ./zookeeper-3.4.9/bin/zkServer.sh start > ZooKeeper JMX enabled by default > Using config: /home/christine/zookeeper-3.4.9/bin/../conf/zoo.cfg > Starting zookeeper ... STARTED > christine@centauri:~$ ./hadoop-3.3.1/sbin/start-dfs.sh > Starting namenodes on [localhost] > Starting datanodes > Starting secondary namenodes [centauri] > centauri: Warning: Permanently added > 'centauri,2003:d4:771c:3b00:7223:40a1:4c07:7c7b' (ECDSA) to the list of known > hosts. > christine@centauri:~$ ./hadoop-3.3.1/sbin/start-yarn.sh > Starting resourcemanager > Starting nodemanagers > christine@centauri:~$ jps > 3921 Jps > 2387 QuorumPeerMain > 3171 SecondaryNameNode > 3732 NodeManager > 2955 DataNode > 3599 ResourceManager > > BUT > when running 'accumulo init' I get this Error: > hristine@centauri:~$ ./accumulo-2.0.1/bin/accumulo init > OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in > version 9.0 and will likely be removed in a future release. > 2021-07-07 15:59:05,590 [conf.SiteConfiguration] INFO : Found Accumulo > configuration on classpath at > /home/christine/accumulo-2.0.1/conf/accumulo.properties > 2021-07-07 15:59:08,460 [fs.VolumeManagerImpl] WARN : > dfs.datanode.synconclose set to false in hdfs-site.xml: data loss is possible > on hard system reset or power loss > 2021-07-07 15:59:08,461 [init.Initialize] INFO : Hadoop Filesystem is > hdfs://localhost:9000 > 2021-07-07 15:59:08,461 [init.Initialize] INFO : Accumulo data dirs are > [hdfs://localhost:8020/accumulo] > 2021-07-07 15:59:08,461 [init.Initialize] INFO : Zookeeper server is > localhost:2181 > 2021-07-07 15:59:08,461 [init.Initialize] INFO : Checking if Zookeeper is > available. If this hangs, then you need to make sure zookeeper is running > 2021-07-07 15:59:08,938 [init.Initialize] ERROR: Fatal exception > java.io.IOException: Failed to check if filesystem already initialized > at > org.apache.accumulo.server.init.Initialize.checkInit(Initialize.java:285) > at org.apache.accumulo.server.init.Initialize.doInit(Initialize.java:323) > at org.apache.accumulo.server.init.Initialize.execute(Initialize.java:991) > at org.apache.accumulo.start.Main.lambda$execKeyword$0(Main.java:129) > at java.base/java.lang.Thread.run(Thread.java:829) > Caused by: java.net.ConnectException: Call From centauri/192.168.178.30 to > localhost:8020 failed on connection exception: java.net.ConnectException: > Connection refused; For more details see: > http://wiki.apache.org/hadoop/ConnectionRefused > at > java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native > Method) > at > java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) > at > java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) > at > java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) > at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:913) > at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:828) > at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1577) > at org.apache.hadoop.ipc.Client.call(Client.java:1519) > at org.apache.hadoop.ipc.Client.call(Client.java:1416) > at > org.apache.hadoop.ipc.ProtobufRpcEngine2$Invoker.invoke(ProtobufRpcEngine2.java:242) > at > org.apache.hadoop.ipc.ProtobufRpcEngine2$Invoker.invoke(ProtobufRpcEngine2.java:129) > at com.sun.proxy.$Proxy18.getFileInfo(Unknown Source) > at > org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:965) > at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native > Method) > at > java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) > at > java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.base/java.lang.reflect.Method.invoke(Method.java:566) > at > org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:422) > at > org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:165) > at > org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:157) > at > org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95) > at > org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:359) > at com.sun.proxy.$Proxy19.getFileInfo(Unknown Source) > at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1731) > at > org.apache.hadoop.hdfs.DistributedFileSystem$29.doCall(DistributedFileSystem.java:1752) > at > org.apache.hadoop.hdfs.DistributedFileSystem$29.doCall(DistributedFileSystem.java:1749) > at > org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81) > at > org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1764) > at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1760) > at > org.apache.accumulo.server.fs.VolumeManagerImpl.exists(VolumeManagerImpl.java:254) > at > org.apache.accumulo.server.init.Initialize.isInitialized(Initialize.java:860) > at > org.apache.accumulo.server.init.Initialize.checkInit(Initialize.java:280) > ... 4 more > Caused by: java.net.ConnectException: Connection refused > at java.base/sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) > at > java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:777) > at > org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206) > at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:586) > at > org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:701) > at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:822) > at org.apache.hadoop.ipc.Client$Connection.access$3800(Client.java:414) > at org.apache.hadoop.ipc.Client.getConnection(Client.java:1647) > at org.apache.hadoop.ipc.Client.call(Client.java:1463) > ... 28 more > 2021-07-07 15:59:08,944 [start.Main] ERROR: Thread 'init' died. > java.lang.RuntimeException: java.io.IOException: Failed to check if > filesystem already initialized > at org.apache.accumulo.server.init.Initialize.execute(Initialize.java:997) > at org.apache.accumulo.start.Main.lambda$execKeyword$0(Main.java:129) > at java.base/java.lang.Thread.run(Thread.java:829) > Caused by: java.io.IOException: Failed to check if filesystem already > initialized > at > org.apache.accumulo.server.init.Initialize.checkInit(Initialize.java:285) > at org.apache.accumulo.server.init.Initialize.doInit(Initialize.java:323) > at org.apache.accumulo.server.init.Initialize.execute(Initialize.java:991) > ... 2 more > Caused by: java.net.ConnectException: Call From centauri/192.168.178.30 to > localhost:8020 failed on connection exception: java.net.ConnectException: > Connection refused; For more details see: > http://wiki.apache.org/hadoop/ConnectionRefused > at > java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native > Method) > at > java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) > at > java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) > at > java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) > at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:913) > at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:828) > at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1577) > at org.apache.hadoop.ipc.Client.call(Client.java:1519) > at org.apache.hadoop.ipc.Client.call(Client.java:1416) > at > org.apache.hadoop.ipc.ProtobufRpcEngine2$Invoker.invoke(ProtobufRpcEngine2.java:242) > at > org.apache.hadoop.ipc.ProtobufRpcEngine2$Invoker.invoke(ProtobufRpcEngine2.java:129) > at com.sun.proxy.$Proxy18.getFileInfo(Unknown Source) > at > org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:965) > at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native > Method) > at > java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) > at > java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.base/java.lang.reflect.Method.invoke(Method.java:566) > at > org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:422) > at > org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:165) > at > org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:157) > at > org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95) > at > org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:359) > at com.sun.proxy.$Proxy19.getFileInfo(Unknown Source) > at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1731) > at > org.apache.hadoop.hdfs.DistributedFileSystem$29.doCall(DistributedFileSystem.java:1752) > at > org.apache.hadoop.hdfs.DistributedFileSystem$29.doCall(DistributedFileSystem.java:1749) > at > org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81) > at > org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1764) > at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1760) > at > org.apache.accumulo.server.fs.VolumeManagerImpl.exists(VolumeManagerImpl.java:254) > at > org.apache.accumulo.server.init.Initialize.isInitialized(Initialize.java:860) > at > org.apache.accumulo.server.init.Initialize.checkInit(Initialize.java:280) > ... 4 more > Caused by: java.net.ConnectException: Connection refused > at java.base/sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) > at > java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:777) > at > org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206) > at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:586) > at > org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:701) > at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:822) > at org.apache.hadoop.ipc.Client$Connection.access$3800(Client.java:414) > at org.apache.hadoop.ipc.Client.getConnection(Client.java:1647) > at org.apache.hadoop.ipc.Client.call(Client.java:1463) > ... 28 more > > > I am not able to find the mistake. I found similar questions on > Stackoverflow, but none of them solved my problem. > Thanks in advance for any idea.
