That makes sense, thanks... My question, howerver: what do i need to do so that my jdbc client could periodically run query on remaining node even if wsrep_ready=OFF?
On Tue, Nov 22, 2016 at 7:21 PM, Diego Dupin <diego.du...@mariadb.com> wrote: > Hi, > > As documented here (https://mariadb.com/kb/en/mariadb/mariadb-galera- > cluster-known-limitations/) : > >> >> - A command may fail with ER_UNKNOWN_COM_ERROR producing 'WSREP has >> not yet prepared node for application use' (or 'Unknown command' in older >> versions) error message. It happens when a cluster is suspected to be >> split >> and the node is in a smaller part — for example, during a network >> glitch, when nodes temporarily lose each other. It can also occur during >> state transfer. The node takes this measure to prevent data inconsistency. >> Its usually a temporary state which can be detected by checking >> wsrep_ready >> <https://mariadb.com/kb/en/galera-cluster-status-variables/#wsrep_ready> >> value. >> The node, however, allows SHOW and SET command during this period. >> >> > if you have only 2 nodes : Quorum requires a majority, meaning that you > cannot have automatic failover in a two node cluster. This is because the > failure of one causes the remaining node automatically go into a > non-primary state. > > > Diego. > > On Wed, Nov 23, 2016 at 12:00 AM, l vic <lvic4...@gmail.com> wrote: > >> i have the following jdbc exception in my jdbc client for the node 1 >> after another node (node2) is removed: >> om.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: >> WSREP has not yet prepared node for application use >> at sun.reflect.GeneratedConstructorAccessor9.newInstance(Unknown >> Source) >> at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(De >> legatingConstructorAccessorImpl.java:45) >> at java.lang.reflect.Constructor.newInstance(Constructor.java:423) >> at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) >> at com.mysql.jdbc.Util.getInstance(Util.java:387) >> at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:917) >> at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3966) >> at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3902) >> at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2526) >> at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2673) >> at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545) >> at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2503) >> at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1369) >> at com.mysql.jdbc.ConnectionImpl.loadServerVariables(Connection >> Impl.java:3833) >> at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(Conn >> ectionImpl.java:3283) >> at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionIm >> pl.java:2297) >> at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083) >> at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806) >> at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) >> at sun.reflect.GeneratedConstructorAccessor5.newInstance(Unknown >> Source) >> at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(De >> legatingConstructorAccessorImpl.java:45) >> at java.lang.reflect.Constructor.newInstance(Constructor.java:423) >> at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) >> at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410) >> at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDr >> iver.java:328) >> at java.sql.DriverManager.getConnection(DriverManager.java:664) >> >> I wonder why i have this failure when i just trying to read db from the >> unaffected node? The failure seems to be permanent, once it happened - all >> subsequent reads fail >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~maria-discuss >> Post to : maria-discuss@lists.launchpad.net >> Unsubscribe : https://launchpad.net/~maria-discuss >> More help : https://help.launchpad.net/ListHelp >> >> >
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