I use PostgreSQL 9.6.6 on CentOS Linux 7.4 and after upgrading the postgresql-jdbc package –

# sudo yum update Failed to set locale, defaulting to C Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile  * base: mirror.fra10.de.leaseweb.net  * epel: mirror.wiuwiu.de  * extras: centosmirror.netcup.net  * updates: mirror.wiuwiu.de Resolving Dependencies --> Running transaction check ---> Package java-1.8.0-openjdk.x86_64 1:1.8.0.151-5.b12.el7_4 will be updated ---> Package java-1.8.0-openjdk.x86_64 1:1.8.0.161-0.b14.el7_4 will be an update ---> Package java-1.8.0-openjdk-headless.x86_64 1:1.8.0.151-5.b12.el7_4 will be updated ---> Package java-1.8.0-openjdk-headless.x86_64 1:1.8.0.161-0.b14.el7_4 will be an update ---> Package postgresql-jdbc.noarch 0:42.1.4-1.rhel7 will be updated ---> Package postgresql-jdbc.noarch 0:42.2.0-1.rhel7 will be an update ---> Package postgresql-jdbc-javadoc.noarch 0:42.1.4-1.rhel7 will be updated ---> Package postgresql-jdbc-javadoc.noarch 0:42.2.0-1.rhel7 will be an update --> Finished Dependency Resolution  Dependencies Resolved  ==============================================================================================================================================================  Package                                          Arch                        Version                                      Repository                    Size ============================================================================================================================================================== Updating:  java-1.8.0-openjdk                               x86_64                      1:1.8.0.161-0.b14.el7_4                      updates                      243 k  java-1.8.0-openjdk-headless                      x86_64                      1:1.8.0.161-0.b14.el7_4                      updates                       32 M  postgresql-jdbc                                  noarch                      42.2.0-1.rhel7                               pgdg96                       566 k  postgresql-jdbc-javadoc                          noarch                      42.2.0-1.rhel7                               pgdg96                       456 k  Transaction Summary ============================================================================================================================================================== Upgrade  4 Packages  Total size: 33 M Total download size: 32 M Is this ok [y/d/N]: y Downloading packages: Delta RPMs disabled because /usr/bin/applydeltarpm not installed. (1/2): java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64.rpm                                                                             | 243 kB  00:00:00      (2/2): java-1.8.0-openjdk-headless-1.8.0.161-0.b14.el7_4.x86_64.rpm                                                                    |  32 MB  00:00:00      -------------------------------------------------------------------------------------------------------------------------------------------------------------- Total                                                                                                                          45 MB/s |  32 MB  00:00:00      Running transaction check Running transaction test Transaction test succeeded Running transaction   Updating   : 1:java-1.8.0-openjdk-headless-1.8.0.161-0.b14.el7_4.x86_64                                                                                 1/8  warning: /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64/jre/lib/security/java.security created as /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64/jre/lib/security/java.security.rpmnew restored /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64/jre/lib/security/java.security.rpmnew to /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64/jre/lib/security/java.security   Updating   : 1:java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64                                                                                          2/8    Updating   : postgresql-jdbc-42.2.0-1.rhel7.noarch                                                                                                      3/8    Updating   : postgresql-jdbc-javadoc-42.2.0-1.rhel7.noarch                                                                                              4/8    Cleanup    : postgresql-jdbc-42.1.4-1.rhel7.noarch                                                                                                      5/8    Cleanup    : 1:java-1.8.0-openjdk-1.8.0.151-5.b12.el7_4.x86_64                                                                                          6/8    Cleanup    : postgresql-jdbc-javadoc-42.1.4-1.rhel7.noarch                                                                                              7/8    Cleanup    : 1:java-1.8.0-openjdk-headless-1.8.0.151-5.b12.el7_4.x86_64                                                                                 8/8    Verifying  : 1:java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64                                                                                          1/8    Verifying  : postgresql-jdbc-42.2.0-1.rhel7.noarch                                                                                                      2/8    Verifying  : 1:java-1.8.0-openjdk-headless-1.8.0.161-0.b14.el7_4.x86_64                                                                                 3/8    Verifying  : postgresql-jdbc-javadoc-42.2.0-1.rhel7.noarch                                                                                              4/8    Verifying  : 1:java-1.8.0-openjdk-1.8.0.151-5.b12.el7_4.x86_64                                                                                          5/8    Verifying  : postgresql-jdbc-javadoc-42.1.4-1.rhel7.noarch                                                                                              6/8    Verifying  : postgresql-jdbc-42.1.4-1.rhel7.noarch                                                                                                      7/8    Verifying  : 1:java-1.8.0-openjdk-headless-1.8.0.151-5.b12.el7_4.x86_64                                                                                 8/8   Updated:   java-1.8.0-openjdk.x86_64 1:1.8.0.161-0.b14.el7_4   java-1.8.0-openjdk-headless.x86_64 1:1.8.0.161-0.b14.el7_4   postgresql-jdbc.noarch 0:42.2.0-1.rhel7     postgresql-jdbc-javadoc.noarch 0:42.2.0-1.rhel7      Complete! 

I am suddenly getting an exception in my previously working Java code (running as WAR in Jetty 9.4.7) right at the connection –

String SQL_MERGE_USERS = "SELECT words_merge_users(?::jsonb, ?::inet, ?::text, ?::text, ?::text)";  // the next line in MyListener.java throws the exception  try (Connection db = DriverManager.getConnection(DATABASE_URL, DATABASE_USER, DATABASE_PASS);         PreparedStatement st = db.prepareStatement(SQL_MERGE_USERS)) {     st.setString(1, users);     st.setString(2, ip);     st.setString(3, fcm);     st.setString(4, apns);     st.setString(5, adm);     ResultSet rs = st.executeQuery(); 

Here the exception copied from the Jetty log (I use pgbouncer at port 6432) –

WARNING: SQLException occurred while connecting to 127.0.0.1:6432 org.postgresql.util.PSQLException: The server's DateStyle parameter was changed to ISO. The JDBC driver requires DateStyle to begin with ISO for correct operation. at org.postgresql.core.v3.QueryExecutorImpl.receiveParameterStatus(QueryExecutorImpl.java:2603) at org.postgresql.core.v3.QueryExecutorImpl.readStartupMessages(QueryExecutorImpl.java:2569) at org.postgresql.core.v3.QueryExecutorImpl.<init>(QueryExecutorImpl.java:131) at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:212) at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49) at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195) at org.postgresql.Driver.makeConnection(Driver.java:452) at org.postgresql.Driver.connect(Driver.java:254) at java.sql.DriverManager.getConnection(DriverManager.java:664) at java.sql.DriverManager.getConnection(DriverManager.java:247) at de.slova.websockets.MyListener.mergeUsers(MyListener.java:152) at de.slova.websockets.MyListener.handleLogin(MyListener.java:208) at de.slova.websockets.MyListener.onWebSocketText(MyListener.java:83) at org.eclipse.jetty.websocket.common.events.JettyListenerEventDriver.onTextMessage(JettyListenerEventDriver.java:189) at org.eclipse.jetty.websocket.common.message.SimpleTextMessage.messageComplete(SimpleTextMessage.java:69) at org.eclipse.jetty.websocket.common.events.AbstractEventDriver.appendMessage(AbstractEventDriver.java:66) at org.eclipse.jetty.websocket.common.events.JettyListenerEventDriver.onTextFrame(JettyListenerEventDriver.java:158) at org.eclipse.jetty.websocket.common.events.AbstractEventDriver.incomingFrame(AbstractEventDriver.java:162) at org.eclipse.jetty.websocket.common.WebSocketSession.incomingFrame(WebSocketSession.java:375) at org.eclipse.jetty.websocket.common.extensions.AbstractExtension.nextIncomingFrame(AbstractExtension.java:182) at org.eclipse.jetty.websocket.common.extensions.compress.PerMessageDeflateExtension.nextIncomingFrame(PerMessageDeflateExtension.java:105) at org.eclipse.jetty.websocket.common.extensions.compress.CompressExtension.forwardIncoming(CompressExtension.java:142) at org.eclipse.jetty.websocket.common.extensions.compress.PerMessageDeflateExtension.incomingFrame(PerMessageDeflateExtension.java:85) at org.eclipse.jetty.websocket.common.extensions.ExtensionStack.incomingFrame(ExtensionStack.java:220) at org.eclipse.jetty.websocket.common.Parser.notifyFrame(Parser.java:220) at org.eclipse.jetty.websocket.common.Parser.parse(Parser.java:256) at org.eclipse.jetty.websocket.common.io.AbstractWebSocketConnection.readParse(AbstractWebSocketConnection.java:679) at org.eclipse.jetty.websocket.common.io.AbstractWebSocketConnection.onFillable(AbstractWebSocketConnection.java:511) at org.eclipse.jetty.io.AbstractConnection$  ReadCallback.succeeded(AbstractConnection.java:279) at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:110) at org.eclipse.jetty.io.ChannelEndPoint$  2.run(ChannelEndPoint.java:124) at org.eclipse.jetty.util.thread.Invocable.invokePreferred(Invocable.java:128) at org.eclipse.jetty.util.thread.Invocable$  InvocableExecutor.invoke(Invocable.java:222) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:294) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:199) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:673) at org.eclipse.jetty.util.thread.QueuedThreadPool$  2.run(QueuedThreadPool.java:591) at java.lang.Thread.run(Thread.java:745) 

I have searched for DateStyle and there is not much information to be found in regard to this error.

From the error text I am not sure what to change – should I modify my Java program or should I change some setting on my Linux server?