The configuration parameters and their default values
| No. |
Property Name |
Default Value |
Description |
| 1 |
driver.max.concurrent.launched.queries |
15 |
Maximum queries which can be launched simultaneously on this driver. This should be equal to lens.driver.jdbc.pool.max.size. This configuration value is only useful when MaxConcurrentDriverQueriesConstraint is enabled by using org.apache.lens.server.api.query.constraint.MaxConcurrentDriverQueriesConstraintFactory as one of the factories in lens.driver.jdbc.query.constraint.factories property. |
| 2 |
lens.cube.query.driver.supported.storages |
|
List of comma separated storage names that supported by a driver. If no value is specified, all storages are valid |
| 3 |
lens.cube.query.partition.where.clause.format |
yyyy-MM-dd HH:mm:ss |
The simple date format of how the queried partition should be put in where clause. If nothing is specified, it will use the format from org.apache.lens.cube.metadata.UpdatePeriod for each type of partition |
| 4 |
lens.cube.query.replace.timedim |
false |
Tells whether timedim attribute queried in the time range should be replaced with its corresponding partition column name. |
| 5 |
lens.cube.query.time.range.writer.class |
org.apache.lens.cube.parse.BetweenTimeRangeWriter |
The timerange writer class which specifies how the resolved partitions in timeranges should be written in final query. Available writers are org.apache.lens.cube.parse.ORTimeRangeWriter and org.apache.lens.cube.parse.BetweenTimeRangeWriter |
| 6 |
lens.driver.jdbc.connection.properties |
|
Connection properties for jdbc connection. |
| 7 |
lens.driver.jdbc.connection.provider |
|
A contract for obtaining JDBC connections |
| 8 |
lens.driver.jdbc.db.password |
|
The database user's password |
| 9 |
lens.driver.jdbc.db.uri |
|
JDBC connection URL in the format jdbc:dbms://host:port/dbname |
| 10 |
lens.driver.jdbc.db.user |
|
The database user on whose behalf the connection is being made |
| 11 |
lens.driver.jdbc.driver.class |
com.mysql.jdbc.Driver |
Type of JDBC driver used to connect backend database |
| 12 |
lens.driver.jdbc.enable.resultset.streaming.retrieval |
false |
Flag to enable row by row retrieval of result set from the database server. This is used to enable streaming result sets for MySQL. This is set to false by default. |
| 13 |
lens.driver.jdbc.estimate.connection.properties |
|
Connection properties for jdbc estimate connection. |
| 14 |
lens.driver.jdbc.estimate.db.password |
|
The database user's password, for estimate queries. If this property is unspecified, value for lens.driver.jdbc.db.password would be used. Override this property to tune estimate connection pool |
| 15 |
lens.driver.jdbc.estimate.db.uri |
|
JDBC connection URL in the format jdbc:dbms://host:port/dbname for estimate queries. If this property is unspecified, value for lens.driver.jdbc.db.uri will be used. |
| 16 |
lens.driver.jdbc.estimate.db.user |
|
The database user on whose behalf the connection is being made, for estimate queries. If this property is unspecified, value for lens.driver.jdbc.db.user would be used. Override this property to tune estimate connection pool |
| 17 |
lens.driver.jdbc.estimate.driver.class |
|
Type of JDBC driver used to connect backend database for estimate queries. If This property is not specified, value for lens.driver.jdbc.driver.class will be used. Override this property to tune estimate connection pool |
| 18 |
lens.driver.jdbc.estimate.get.connection.timeout |
|
Response timeout in milliseconds of any JDBC call invoking data transmission over a connection socket , for estimate queries. If this property is not specified, value for lens.driver.jdbc.get.connection.timeout would be used. Override this property to tune estimate connection pool. |
| 19 |
lens.driver.jdbc.estimate.pool.idle.time |
|
Maximum idle time in sec before a connection is closed, for estimate queries. If this property is not specified, value for lens.driver.jdbc.pool.idle.time would be used. Override this property to tune estimate connection pool. |
| 20 |
lens.driver.jdbc.estimate.pool.max.size |
|
Maximum number of concurrent connections allowed in pool, for estimate queries. If this property is unspecified, value for lens.driver.jdbc.pool.max.size would be used. Override this property to tune estimate connection pool |
| 21 |
lens.driver.jdbc.estimate.pool.max.statements |
|
Maximum number of prepared statements to cache per connection, for estimate queries. If this property is not specified, value for lens.driver.jdbc.pool.max.statements would be used. |
| 22 |
lens.driver.jdbc.explain.keyword |
Explain |
Explain keyword used to get the query plan of underlying database |
| 23 |
lens.driver.jdbc.fetch.size |
1000 |
Fetch size for JDBC result set |
| 24 |
lens.driver.jdbc.get.connection.timeout |
10000 |
The number of milliseconds a client calling getConnection() will wait for a Connection to be checked-in or acquired when the pool is exhausted. Zero means wait indefinitely. Setting any positive value will cause the getConnection () call to time-out and break with an SQLException after the specified number of milliseconds. The default value of this property is 10 secs. |
| 25 |
lens.driver.jdbc.pool.idle.time |
600 |
Maximum idle time in sec before a connection is closed |
| 26 |
lens.driver.jdbc.pool.max.size |
15 |
Maximum number of concurrent connections allowed in pool |
| 27 |
lens.driver.jdbc.pool.max.statements |
20 |
Maximum number of prepared statements to cache per connection |
| 28 org.apache.lens.driver.jdbc.MaxJDBCConnectionCheckConstraintFactory |
lens.driver.jdbc.query.launching.constraint.factories Factories used to instantiate constraints enforced on queries by driver. A query will be launched only if all constraints pass. Every Factory should be an implementation of org.apache.lens.server.api.common.ConfigBasedObjectCreationFactory and create an implementation of org.apache.lens.server.api.query.constraint.QueryLaunchingConstraint. |
org.apache.lens.server.api.query.constraint.MaxConcurrentDriverQueriesConstraintFactory, |
|
| 29 |
lens.driver.jdbc.query.rewriter |
org.apache.lens.driver.jdbc.ColumnarSQLRewriter |
Rewriting the HQL to optimized sql queries |
| 30 |
lens.driver.jdbc.regex.replacement.values |
to_date=date, format_number=format, date_sub ((.*?) , s*([0-9]+ s*) )=date_sub($1 , interval $2 day), date_add ((.*?) , s*([0-9]+ s*) )=date_add($1 , interval $2 day) |
Rewriting the HQL to optimized sql queries |
| 31 |
lens.driver.jdbc.statement.cancel.supported |
true |
Flag to indicate Whether cancel on JDBC statement is supported. If not supported, framework wont call cancel on JDBC statement. |
| 32 |
lens.driver.jdbc.validate.through.prepare |
true |
Flag to enable query syntactic and semantic validation using prepared statement. |
| 33 |
lens.driver.jdbc.waiting.queries.selection.policy.factories |
org.apache.lens.server.api.query.collect.DriverSpecificWaitingQueriesSelectionPolicyFactory |
Factories used to instantiate driver specific waiting queries selection policies. Every factory should be an implementation of org.apache.lens.server.api.common.ConfigBasedObjectCreationFactory and create an implementation of org.apache.lens.server.api.query.collect.WaitingQueriesSelectionPolicy. |
| 34 |
lens.query.timeout.millis |
3600000 |
The runtime(millis) of the query after which query will be timedout and cancelled. Default is 1 hour for jdbc queries. |
