com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

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Hello, I am testing the JWPL api with the Hello World example listed in the 
tutorials:
https://code.google.com/p/jwpl/source/browse/trunk/de.tudarmstadt.ukp.wikipedia.
api/src/main/java/de/tudarmstadt/ukp/wikipedia/api/tutorial/T1a_HelloWorld.java

But received the following MySQL connection exception. I have my MySQL 5.6.24 
installed, and started it. Before I run the tutorials, do I have to create some 
tables in MySQL to run these examples? Thank you.

02:11:31,057  INFO AbstractPoolBackedDataSource:462 - Initializing c3p0 pool... 
com.mchange.v2.c3p0.PoolBackedDataSource@f56923d7 [ connectionPoolDataSource -> 
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@76380f40 [ acquireIncrement 
-> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose 
-> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, 
checkoutTimeout -> 0, connectionCustomizerClassName -> null, 
connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, 
debugUnreturnedConnectionStackTraces -> false, factoryClassLocation -> null, 
forceIgnoreUnresolvedTransactions -> false, identityToken -> 
z8kflt991ghtq05uwy5aq|365de953, idleConnectionTestPeriod -> 300, 
initialPoolSize -> 3, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, 
maxIdleTime -> 1000, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 15, 
maxStatements -> 10, maxStatementsPerConnection -> 0, minPoolSize -> 3, 
nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@bee79ef8 [ 
description -> null, driverClass -> null, factoryClassLocation -> null, 
identityToken -> z8kflt991ghtq05uwy5aq|75bd0815, jdbcUrl -> 
jdbc:mysql://SERVER_URL/DATABASE, properties -> {useUnicode=true, user=******, 
password=******, characterEncoding=UTF-8} ], preferredTestQuery -> null, 
propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout 
-> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> 
false; userOverrides: {} ], dataSourceName -> null, factoryClassLocation -> 
null, identityToken -> z8kflt991ghtq05uwy5aq|45d9a778, numHelperThreads -> 3 ]
02:12:00,466  WARN BasicResourcePool:1841 - 
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@33e5c671 -- 
Acquisition Attempt Failed!!! Clearing pending acquires. While trying to 
acquire a needed new resource, we failed to succeed more than the maximum 
number of allowed acquisition attempts (30). Last acquisition attempt 
exception: 
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link 
failure

The last packet sent successfully to the server was 0 milliseconds ago. The 
driver has not received any packets from the server.
    at sun.reflect.GeneratedConstructorAccessor6.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1117)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:350)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2393)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2430)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.GeneratedConstructorAccessor9.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334)
    at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:135)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
    at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
    at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
    at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Caused by: java.net.UnknownHostException: SERVER_URL
    at java.net.InetAddress.getAllByName0(InetAddress.java:1250)
    at java.net.InetAddress.getAllByName(InetAddress.java:1162)
    at java.net.InetAddress.getAllByName(InetAddress.java:1098)
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:247)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:300)

Original issue reported on code.google.com by lingv...@gmail.com on 4 Jun 2015 at 6:29

[GoogleCodeExporter]

Any comment on this? Thank you. How can I run the tutorial?

Original comment by lingv...@gmail.com on 4 Jun 2015 at 5:05

[GoogleCodeExporter]

Please follow this guide: 
https://code.google.com/p/jwpl/wiki/JWPLCore_GettingStarted. In particular, you 
need to set up a database from a Wikipedia dump as described here: 
https://code.google.com/p/jwpl/wiki/DataMachine.

Original comment by daxenber...@gmail.com on 5 Jun 2015 at 8:35

• Changed state: Invalid