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Below is a simple code snippet that shows how to connect to a VoltDB server. 

ClientConfig clientConfig = new ClientConfig();
Client client = ClientFactory.createClient(clientConfig);
String server = "192.168.43.32";
client.createConnection(server);

Based on my experiments, if the server is down or just not connectable from network layer, it will take about 75 seconds to get the response.

SEVERE: Failed to connect to 192.168.43.32, in 75,359 ms
java.net.ConnectException: Operation timed out
    at sun.nio.ch.Net.connect0(Native Method)
    at sun.nio.ch.Net.connect(Net.java:458)
    at sun.nio.ch.Net.connect(Net.java:450)
    at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:648)
    at java.nio.channels.SocketChannel.open(SocketChannel.java:189)
    at org.voltdb.client.ConnectionUtil.getAuthenticatedConnection(ConnectionUtil.java:154)
    at org.voltdb.client.ConnectionUtil.getAuthenticatedConnection(ConnectionUtil.java:142)
    at org.voltdb.client.ConnectionUtil.getAuthenticatedConnection(ConnectionUtil.java:134)
    at org.voltdb.client.Distributer.createConnectionWithHashedCredentials(Distributer.java:878)
    at org.voltdb.client.ClientImpl.createConnectionWithHashedCredentials(ClientImpl.java:189)
    at org.voltdb.client.ClientImpl.createConnection(ClientImpl.java:682)
    at src.java.tutorial.voltdb.integration.ConnectionTest.main(ConnectionTest.java:27)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

Is there any ways to set the time out time, so the application needs not to wait for such a long time. A successful connection normally takes just tens of milliseconds, so I think if the connection cannot be established within 1000 milliseconds, something is definitely wrong already.

I have tried the setting of below

clientConfig.setConnectionResponseTimeout(1000);

In this case, it has no effects at all. So I guess it is not for this purpose.

David
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1 Answers1

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Normally when the database is down and your client tries to connect it will get an immediate Connection refused exception, for example: 

Exception in thread "main" java.net.ConnectException: Connection refused
at sun.nio.ch.Net.connect0(Native Method)
at sun.nio.ch.Net.connect(Net.java:364)
at sun.nio.ch.Net.connect(Net.java:356)
at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:623)
at java.nio.channels.SocketChannel.open(SocketChannel.java:184)
at org.voltdb.client.ConnectionUtil.getAuthenticatedConnection(ConnectionUtil.java:165)
at org.voltdb.client.ConnectionUtil.getAuthenticatedConnection(ConnectionUtil.java:153)
at org.voltdb.client.ConnectionUtil.getAuthenticatedConnection(ConnectionUtil.java:145)
at org.voltdb.client.Distributer.createConnectionWithHashedCredentials(Distributer.java:890)
at org.voltdb.client.ClientImpl.createConnectionWithHashedCredentials(ClientImpl.java:191)
at org.voltdb.client.ClientImpl.createConnection(ClientImpl.java:684)
at benchmark.Benchmark.<init>(Benchmark.java:17)
at benchmark.Benchmark.main(Benchmark.java:78)

In general, a "java.net.ConnectException: Connection timed out" can occur if there is a firewall that prevents the client from receiving any sort of response, or there could be other causes. The first thing to check might be if you have any firewall or network settings that would prevent access to port 21212 (the default VoltDB database connection port).

The ClientConfig setConnectionResponseTimeout() setting is used to cause a live connection to be closed if it hasn't received a response from a procedure call or a ping for the given number of milliseconds, but it is not used for creating a new connection.

BenjaminBallard
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