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.dupin@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 <lvic4594@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
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