Java Doc for DatabaseBackend.java in  » Database-JDBC-Connection-Pool » sequoia-2.10.9 » org » continuent » sequoia » controller » backend » Java Source Code / Java DocumentationJava Source Code and Java Documentation

The DatabaseBackend objects cannot be serialized because they are used as MBean and notification emitters, so we want to extract the BackendInfo (which are Serializable) out of them.

This method does not keep the XML configuration of the BackendInfo objects.

If no schema has been defined, the first gathered schema is used as the current database schema.

For each schema that is not compatible with the current schema, a warning is issued on the logger for that backend
Parameters:
  c - optional connection from which the schema should be fetched (nullif not applicable) true if compatible, false otherwise

• driverPath: the path to the driver
• driver: the driver class name
• url: the url to connect to the database
• connectionTestStatement: the query to test theconnection

 data[0] = this.name;
 data[1] = this.driverClassName;
 data[2] = this.url;
 data[3] = String.valueOf(this.activeTransactions.size());
 data[4] = String.valueOf(this.pendingRequests.size());
 data[5] = String.valueOf(this.isReadEnabled());
 data[6] = String.valueOf(this.isWriteEnabled());
 data[7] = String.valueOf(this.isInitialized());
 data[8] = String.valueOf(this.schemaIsStatic);
 data[9] = String.valueOf(this.connectionManagers.size());
 data[10] = String.valueOf(getTotalActiveConnections());
 data[11] = String.valueOf(totalRequest);
 data[12] = String.valueOf(totalTransactions);
 data[13] = lastKnownCheckpoint;
 

Reads are no more allowed on the backend and the state is updated so that isReadEnabled() returns false.
See Also:   DatabaseBackend.disable()
See Also:   DatabaseBackend.isReadEnabled()

The DatabaseBackend objects cannot be serialized because they are used as MBean and notification emitters, so we want to extract the BackendInfo (which are Serializable) out of them.

This method does not keep the XML configuration of the BackendInfo objects. Subsequent calls to getXml() on BackendInfos returned by this method will always return null

TODO: a full refresh is forced on CREATE request to be sure to properly handle foreign keys (see SEQUOIA-581). An improvement would be not to refresh the whole schema on each create request - just add the new table and fetch its dependencies (foreign keys) by reloading exported keys of existing tables (see SEQUOIA-xxx). Similar optimization may be done on ALTER requests but it would require to be able to parse the request - currently we just force a full schema refresh. Note that concerning DROP request, we remove the table from dependending tables of other tables in addition to the removal of the table from the schema (given t1 and t2 tables, if t2 has a fk referencing t1, the table t1 will have the table t2 in its dependending tables). In case of rollback, these modification will be cancelled because the schema will be refreshed.
Parameters:
  request - the request that possibly updates the schema