This chapter contains instructions for using the advanced SharePlex configuration options of named queues. These options provide an additional level of flexibility to divide and parallelize data to meet specific processing and routing requirements. Before proceeding, make certain you understand the concepts and processes in Configure data replication.
About this Guide
Conventions used in this guide
Overview of SharePlex
Advantages of SharePlex
About source and target data
About SharePlex architecture
How SharePlex replication works
Understanding the concept of synchronization
Strategies for information availability
Run SharePlex
Run multiple instances of SharePlex
Run multiple instances of SharePlex from separate installations
Run multiple instances of SharePlex from one installation
Execute commands in sp_ctrl
How to run sp_ctrl
Define a default port for sp_ctrl
Define a default host for sp_ctrl
Set a default editor for sp_ctrl
Command guidelines
Issue commands on a remote system
Issue commands for a clustered system
Add a scroll bar to output on Windows
Set SharePlex parameters
Configure data replication
Ensure compatible source-target mapping
Create a configuration file
How to qualify object names
How to specify case-sensitive names
Database specifications in a configuration file
Target specifications in a configuration file
Routing specifications in a configuration file
Configuration examples
Capture from multiple local datasources
Use Wildcards to specify multiple objects
Define a unique key
Filter DML operations
Map source columns to target columns
Build a configuration file using a script
Configure replication to and from a container database
Configure named queues
Configure partitioned replication
Configure replication to a change history target
Configure a replication strategy
Configure Replication to share or distribute data
Configure Replication to maintain a central data store
Configure peer-to-peer replication
Configure Replication through an intermediary system
Configure Replication to maintain high availability
Configure DDL replication
DDL that SharePlex supports
Enable DDL replication
Filter DDL Replication
Best practices for ALTER TABLE DDL
DDL logging and error handling
Configure error handling
Continue to Post when there is an error
Continue to Post on DDL errors
Increase the number of retries on error
Handle transactions that contain out-of-sync operations
Configure data transformation
Configure security features
Secure data with SSL/TLS
Host Authentication
Secure data with SSH
Encrypt data between Export and Import
Assign SharePlex users to security groups
Start replication on your production systems
What is activation?
Activation commands
Requirements for activating a configuration
Test the configuration before activation
Frequently Asked Questions about activation
How to activate multiple configuration files
Activate replication with an Oracle hot backup on an active database
Activate replication with an Oracle hot backup on a quiet database
Activate replication with Oracle transportable tablespaces
Activate replication with cold copy/transfer methods
Activate replication from Oracle to Open Target
Monitor SharePlex
View and kill SharePlex processes
View events and errors
Monitor with sp_ctrl commands
Run monitor scripts on UNIX
Prevent and solve replication problems
Monitor Oracle capture with sp_logmon
Monitor events with sp_eventmon
Monitor processes with sp_ps
Monitor queues with sp_qstatmon
Run a monitor script on Windows
Monitor with SNMP
Find the problem in the SharePlex Knowledge Base
Solve database setup problems
Solve configuration file problems
Solve activation problems
Solve replication problems
Solve Oracle DDL replication problems
Solve queue problems
Solve synchronization problems
Solve compare command errors
Solve other problems
How to resynchronize source and target objects
How to restore Oracle archive logs
How to release semaphores after process failure
How to resolve disk space shortage
How to find the ORACLE_SID and ORACLE_HOME
Repair out-of-sync data
Overview of Compare and Repair
Before you use Compare and Repair
How to use the repair and compare commands
Tune the Capture process
Tune the Post process
Use INDEX hints
Tune SQL Caching
Adjust open cursors
Skip maintenance DML
Make small transactions faster
Split a large transaction into a smaller one
Tune queue performance
Tune hash-based horizontally partitioned replication
Recover replication after Oracle failover
Recover replication if the primary system fails
Recover replication if the secondary Oracle instance fails
Move replication during planned failover and failback
Resume replication after failure and recovery
Make changes to an active replication environment
Change a configuration file
Add or change table specifications in an active replication configuration
Change Partitioned Replication
Add Oracle sequences to an active replication configuration
Remove objects from replication
Make DDL changes in an active replication configuration
Make Oracle changes that affect replication
Change the SharePlex database account
Change the name or IP address of a replication host
Set the SharePlex port number
Apply an Oracle application patch or upgrade
Before you patch or upgrade an application
Apply patch/upgrade to source then copy it to target
Apply patch/upgrade to source and target
Apply patch to source and replicate it to the target
Back up Oracle data on the source or target
Troubleshooting Tips
Appendix A: Peer-To-Peer Diagram
Appendix B: SharePlex environment variables
Configure named queues
Configure named queues
Configure named export queues
A named export queue is an optional, user-defined export queue that is attached to its own Export process. SharePlex creates each named Export queue and associated Export process in addition to the default export queue-process pair. When SharePlex creates a named export queue-process pair, it also creates a dedicated Import process, post queue, and Post process on the target to contain that data stream.
You direct SharePlex to create one or more named export queues when you create your configuration file. Any data that is not configured for processing through a named export queue is processed through the default export queue.
Supported sources
Oracle
Supported targets
All
Benefits of named export queues
Use named export queues to isolate the replication of:
- Individual configurations: By default, SharePlex sends data from all active configurations through one export queue-process pair per target system, but the use of named Export queues enables you to separate each of those replication streams into its own export queue and Export process. In this way, you ensure that purge config or abort config commands that are issued for one configuration do not affect any of the others.
- Selected database objects: You can use a named export queue to isolate certain objects such as tables that contain LOBs. Because each named export queue has its own Import process, post queue, and Post process on the target, you are able to isolate the data the entire way from source to target. For more information about the benefits of named post queues, see Configure named post queues.
Additional benefits:
- You can stop the Export or Import process for one data stream, while allowing the others to continue processing.
- You can set SharePlex parameters to different settings for each export queue-process pair. This enables you to tune the performance of the Export processes based on the objects replicating through each one.
Considerations when using named export queues
- Make certain that each queue name is unique.
-
You can combine named export queues with default export queues. Tables in the configuration with a standard routing map (targetsys@database_spec without a named queue specification) are replicated through a default export queue.
- All tables with referential integrity to one another must be in the same export queue.
- SharePlex has a maximum number of allowed queues. For more information, see Routing specifications in a configuration file.
Note: If Post returns the error message "shs_SEMERR: an error occurred with the semaphore" on a Windows system, the number of semaphores may need to be increased to accommodate the queues that you created. For more information, see Post stopped .
Configure a named export queue
Use the following syntax to define a routing map that includes a named export queue.
source_host:export_queuename*target_host[@database]
Configuration with named export queue in routing map
| Datasource: o.SID | ||
| src_owner.table | tgt_owner.table |
source_host:export_queue*target_host[@database_specification] |
| Routing component | Description |
|---|---|
| source_host | The name of the source system. |
| export_queue |
The name of the export queue. Queue names are case-sensitive on all platforms. Use one word only. Underscores are permissible, for example: sys1:export_q1*sys2@o.myora |
| target_host | The name of the target system. |
| database specification |
One of the following for the datasource: o.oracle_SID r.database_name
One of the following if the target is a database: o.oracle_SID o.tns_alias o.PDBname r.database_name c.oracle_SID |
NoteS:
- Allow no spaces between any components in the syntax of the routing map.
- For more information about the components of a configuration file, see Configure data replication.
Examples
The following configuration files show two different datasources that are being replicated to two different databases on the same target system. Each datasource is routed through a named export queue.
| Datasource:o.oraA | ||
| scott.emp | scott.emp | sysA:QueueA*sysB@o.oraC |
| scott.sales | scott.sales | sysA:QueueA*sysB@o.oraC |
| Datasource:o.oraB | ||
| scott.prod | scott.prod | sysA:QueueB*sysB@o.oraD |
| scott.cust | scott.cust | sysA:QueueB*sysB@o.oraD |
The following shows how to separate a table that contains LOBs from the rest of the tables by using named export queues.
| Datasource:o.oraA | ||
| scott.cust | scott.cust | sysA:QueueA*sysB@o.oraC |
| scott.sales | scott.sales | sysA:QueueA*sysB@o.oraC |
| scott.prod | scott.prod | sysA:QueueA*sysB@o.oraC |
| scott.emp_LOB | scott.emp_LOB | sysA:QueueB*sysB@o.oraC |
Alternatively, you could simply define a named export queue for the LOB table and allow the remaining tables to be processed through the default export queue.
| Datasource:o.oraA | ||
| scott.cust | scott.cust | sysB@o.oraC |
| scott.sales | scott.sales | sysB@o.oraC |
| scott.prod | scott.prod | sysB@o.oraC |
| scott.emp_LOB | scott.emp_LOB | sysA:lobQ*sysB@o.oraC |
How to identify named export queues
You can view named export queues through sp_ctrl:
- Use the qstatus command to view all queues on a system.
- Use the show command to view all Export processes with their queues.
See the SharePlex Reference Guide for more infomation about theses commands.
Configure named post queues
A named post queue is an optional component of the routing map in the configuration file. A named post queue is a user-defined post queue with its own Post process, which together operate in parallel to the default post queue and Post process. You can define one or more named post queue-process pairs to establish a set of parallel Post replication streams.
Supported sources
Oracle
Supported targets
All
Benefits of named post queues
You can use named post queues to isolate data from different tables into two or more separate Post streams. By using named post queues, you can improve posting performance by isolating objects such as the following that cause processing bottlenecks:
- large tables
- objects that have LOB columns. Named post queues are recommended for objects that contain LOBs.
- objects that involve large transactions.
- any objects whose operations you want to isolate.
Process the remaining objects through additional named post queues, or use the default post queue. Objects in the configuration file with a standard routing map (host@target) are replicated through a default post queue.
You can use horizontal partitioning to divide the rows of very large tables into separate named post queues as an added measure of parallelism.
You can set SharePlex parameters to different settings for each queue-process pair. This enables you to tune the performance of the Post processes based on the objects replicating through each one.
Considerations when using named post queues
- The analyze config command can help you determine how to organize your tables into named queues, based on any dependencies they have and their individual transactional activity. Run the command over a period of time that captures typical database activity, and then view the command output.
- Assign each post queue a unique name.
- If objects are linked by relational dependencies, process all of those objects through the same named post queue. If interdependent objects are not replicated through the same post queue, parent and child operations may be applied out of order and will cause database errors. As an alternative to processing interdependent objects through the same queue, you can disable their referential constraints on the target. This may be acceptable, because the constraints are satisfied on the source system and then replicated to the target.
- When using multiple Posts, the target objects might not be changed in the same order as the corresponding source objects, possibly causing the target database to be inconsistent with the source database at any given point in time.
- If you implement named post queues for objects in an active configuration (thus changing the routing) SharePlex locks those objects to update its internal directions.
-
SharePlex has a maximum number of allowed queues. For more information, see Routing specifications in a configuration file.
Note: If Post returns the error message "shs_SEMERR: an error occurred with the semaphore" on a Windows system, the number of semaphores may need to be increased to accommodate the queues that you created. For more information, see Post stopped .
Configure a named post queue
If you are using named export queues, SharePlex creates a named post queue-process pair for each one by default. If you are not using named export queues, use the following syntax to define a named post queue in the configuration file by adding the :queue component to the routing map:
host:queue@target
Configuration with named post queue in routing map
| Datasource: o.SID | ||
| src_owner.table | tgt_owner.table |
host:queue[@database_specification] |
| Routing component | Description |
|---|---|
| host | The name of the target system. |
| queue |
The unique name of the post queue. Queue names are case-sensitive on all platforms. One word only. Underscores are permissible, for example: sys2:post_q1@o.myora |
| database_specification |
One of the following for the datasource: o.oracle_SID
One of the following if the target is a database:
|
NoteS:
- Allow no spaces between any components in the syntax of the routing map.
- For more information, see Configure data replication.
Examples
The following configuration creates one post queue named Queue1 that routes data from table scott.emp and another post queue named Queue2 that routes data from table scott.cust.
| Datasource:o.oraA | ||
| scott.emp | scott.emp | sysB:Queue1@o.oraC |
| scott.cust | scott.cust |
sysB:Queue2@o.oraC |
The following shows how a named post queue is specified when you are routing data in a pass-through configuration using an intermediary system. For more information, see Configure replication to share or distribute data.
| Datasource:o.oraA | ||
| scott.emp | scott.emp | sysB*sysC:Queue1@o.oraC |
How to identify a named post queue
A named post queue is identified by the datasource (source of the data) and one of the following:
- the name of an associated named export queue (if the Import is linked to a named export queue)
- the user-assigned post-queue name (if the Import is linked to a default export queue).
You can view named post queues through sp_ctrl:
- Use the qstatus command to view all queues on a system.
- Use the show command to view all Post processes with their queues.
See the SharePlex Reference Guide for more infomation about theses commands.
Configure partitioned replication
Configure partitioned replication
This chapter contains instructions for using the advanced SharePlex configuration options of horizontally partitioned and vertically partitioned replication. These options provide an additional level of flexibility to divide, parallelize, and filter data to meet specific requirements. Before proceeding, make certain you understand the concepts and processes in Configure data replication.