Requirements for activating a configuration
Activation of a configuration is an event that requires a series of actions to be taken in a timely manner, uninterrupted. Therefore, it is important to have all of your preparations done ahead of time, leaving nothing in question. You can activate a configuration if you performed the minimal requirements outlined in this topic.
Note: These instructions apply to Oracle source databases, unless otherwise noted.
Required authorization level
Only a SharePlex Administrator can activate a configuration. Additional users should be assigned to monitor SharePlex and perform basic operational procedures. For more information, see Assign SharePlex Users to Security Groups.
Required setup
- Before you activate a configuration, make certain that the objects that you want to replicate exist in the source database.
- If a table will be partitioned, create those partitions before you activate a configuration to begin replication processing. Partitioning a table while it is actively replicating causes SharePlex to lose the identifying information it has compiled, and DML from that table partition will not be replicated. You can add a partition to a table already in replication, but you will need to reactivate the configuration to update that table in the SharePlex object cache. For additional information related to adding or dropping the partitioned table for PostgreSQL, see the Activate Config for PostgreSQL section in the SharePlex Reference Guide.
Prerequisites:
Make certain you satisfy the following prerequisites before you activate a configuration.
Test the configuration before activation
Before you activate a configuration in production, perform a test activation by using the verify config command. If there are syntax errors, misspellings or duplicate entries in the configuration file, the entire activation will fail.
This command will test the configuration to find and report the following conditions:
- Verify the syntax of the entries in the configuration file.
- Report an error if the source object is not supported for replication by SharePlex.
- Report if a host name specified in a route is unreachable.
- Report if there are duplicate specifications for a single object.
- Report if an object specification will be skipped and the reason why.
The verify config command does not verify how long the activation will take, nor will it verify the target objects or database connection (as represented by the database identifier listed in the routing map.)
For more information, see the verify config command in the SharePlex Reference Guide.
Frequently Asked Questions about activation
What happens during activation?
During activation, SharePlex gets the information it needs to identify and understand the objects that are configured for replication and build routing maps. For more information, see What is Activation?.
How long does activation take?
The length of time that activation takes varies, depending on the size, number and structure of the configured objects.
Do users have to stop access to the data?
An Oracle database can remain available for transactions. Each source table is briefly locked so SharePlex can build its internal object information. Then the lock is released. This happens very quickly and may not even be noticeable by users. However, if a business application has NOWAIT locking, the SharePlex lock may cause the application to fail if it attempts to obtain a lock on an object that is being activated.
Can DDL be performed during activation?
No. The definition of objects cannot be changed during activation.
Can I activate multiple configurations for the same datasource?
Yes. You can create different configurations for the same datasource. You must use multiple instances of SharePlex (different sp_cop processes and variable-data directories, running on different ports). See Run Multiple Instances of SharePlex
Can I activate configurations for different datasources at the same time?
Yes. For more information, see How to Activate Multiple Configuration Files.
Can I test a configuration before I activate it?
Yes. This is highly recommended. Use the verify config command. For more information, see Requirements for Activating a Configuration.
Can I interrupt an activation to make changes?
No. Activation is meant to be an uninterrupted procedure that initiates replication while maintaining the same series of transactional events as those appearing in the redo log. You can use the abort config command to terminate an activation, but you may then need to clean out the queues and resynchronize the source and target data again. Ideally, you should have a tested configuration file ready to be activated and be prepared to issue commands to the database and to SharePlex.
Can I activate against a quiet database?
Yes. A quiet database is optional to activate Oracle capture. The Oracle database must be mounted and open, however.
Can I increase the number of activation threads?
Yes, but only for an Oracle source. The number of threads is controlled globally by the SP_OCF_THREAD_COUNT parameter, which must be set before you issue the activate config command. You can override this value for a particular activation by using the threads option when you issue the activate config command.
How to activate multiple configuration files
You can activate one configuration per datasource on a system. For example, if there are ConfigA, ConfigB and ConfigC for the same datasource, you can activate only one of them at a time. Activating another configuration for the same datasource automatically deactivates the first one.
However, if ConfigA replicates data from one datasource, while ConfigB replicates data from a different datasource, you can activate both of those configurations at the same time. Replication for those configurations can operate concurrently.
To activate multiple configuration files:
The activation process retains control of the sp_ctrl interface until the activation is finished. Because an activation can take a significant amount of time, you can activate different configurations in different sessions of sp_ctrl. Activate the first configuration, then open another session of sp_ctrl to activate the second one. Open as many sessions of sp_ctrl as you have configurations to activate.
The number of activation threads can be controlled for an Oracle source. To set the number of threads, use the SP_OCF_THREAD_COUNT parameter, which is a global setting for the instance of SharePlex. When activating more than one configuration concurrently, you can override this value for a particular activation by using the threads option when you issue the activate config command.
