Hi all,
I am trying to built an IoT demo, where data from my Raspberry Pi will be stored in NoSQL. And since I intend to use the Python & Node.js API's, I followed the documentation instructions to set up a proxy server in the Pi.
Problem is, the proxy server (running in the Pi) is unable to find the NoSQL host, even if I use the host IP address (192.168.70.74):
| pi@raspberrypi:~ $ | export CLASSPATH="/usr/local/lib/python2.7/dist-packages/nosqldb/kvproxy/lib/*" |
pi@raspberrypi:~ $ java oracle.kv.proxy.KVProxy -port 7010 -helper-hosts 192.168.70.74:5000 -store kvstore
Feb 06, 2017 11:09:28 AM oracle.kv.proxy.KVProxy <init>
INFO: PS: Starting KVProxy server
Feb 06, 2017 11:09:28 AM oracle.kv.proxy.KVProxy <init>
INFO: PS: Connect to Oracle NoSQL Database kvstore nodes : 192.168.70.74:5000
Exception in thread "main" oracle.kv.FaultException: Could not contact any RepNode at: [192.168.70.74:5000] (12.1.4.3.10)
Fault class name: oracle.kv.KVStoreException
| | at oracle.kv.KVStoreFactory.getStoreInternal(KVStoreFactory.java:227) |
| | at oracle.kv.KVStoreFactory.getStore(KVStoreFactory.java:122) |
| | at oracle.kv.KVStoreFactory.getStore(KVStoreFactory.java:59) |
| | at oracle.kv.proxy.KVProxy.<init>(KVProxy.java:125) |
| | at oracle.kv.proxy.KVProxy.startServer(KVProxy.java:161) |
| | at oracle.kv.proxy.KVProxy.main(KVProxy.java:151) |
Caused by: oracle.kv.KVStoreException: Could not contact any RepNode at: [192.168.70.74:5000]
| | at oracle.kv.impl.util.TopologyLocator.getInitialTopology(TopologyLocator.java:246) |
| | at oracle.kv.impl.util.TopologyLocator.get(TopologyLocator.java:83) |
| | at oracle.kv.impl.api.RequestDispatcherImpl.<init>(RequestDispatcherImpl.java:330) |
| | at oracle.kv.KVStoreFactory.getStoreInternal(KVStoreFactory.java:214) |
| | ... 5 more |
Caused by: java.rmi.UnknownHostException: Unknown host: bigdatalite.localdomain; nested exception is:
| | java.net.UnknownHostException: bigdatalite.localdomain |
| | at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:616) |
| | at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:216) |
| | at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:202) |
| | at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:130) |
| | at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:227) |
| | at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:179) |
| | at com.sun.proxy.$Proxy0.getSerialVersion(Unknown Source) |
| | at oracle.kv.impl.util.registry.RemoteAPI.<init>(RemoteAPI.java:40) |
| | at oracle.kv.impl.rep.admin.RepNodeAdminAPI.<init>(RepNodeAdminAPI.java:67) |
| | at oracle.kv.impl.rep.admin.RepNodeAdminAPI.wrap(RepNodeAdminAPI.java:76) |
| | at oracle.kv.impl.util.TopologyLocator$3.run(TopologyLocator.java:313) |
| | at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) |
| | at java.util.concurrent.FutureTask.run(FutureTask.java:266) |
| | at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) |
| | at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) |
| | at java.lang.Thread.run(Thread.java:745) |
Caused by: java.net.UnknownHostException: bigdatalite.localdomain
| | at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) |
| | at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) |
| | at java.net.Socket.connect(Socket.java:589) |
| | at oracle.kv.impl.util.registry.ClientSocketFactory.createTimeoutSocket(ClientSocketFactory.java:360) |
| | at oracle.kv.impl.util.registry.ClientSocketFactory.createSocket(ClientSocketFactory.java:347) |
| | at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:613) |
| | ... 15 more |
bigdatalite.localdomain is the hostname where NoSQL DB is running.
I was able to find a workaround, by including the host's IP address in the Pi's /etc/hosts file, after which the connection works properly; nevertheless, it feels like a hack.
I unearthed an old Stack Overflow question, where it is implied that the KVStore requires the hostname, but I could not locate such a requirement in the admin installation guide.
So, is this expected behavior? And if yes, could someone point to the relevant section in the installation documentation?
Many thanks in advance.
Christos