maria-discuss team mailing list archive

[Diego Dupin <diego.dupin@xxxxxxxxxxx>]

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@xxxxxxxxx> 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(
> DelegatingConstructorAccessorImpl.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(
> ConnectionImpl.java:3833)
>    at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(
> ConnectionImpl.java:3283)
>    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(
> ConnectionImpl.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(
> DelegatingConstructorAccessorImpl.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(
> NonRegisteringDriver.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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