|Oracle® Fusion Middleware Performance and Tuning Guide
11g Release 1 (11.1.1)
Part Number E10108-01
This chapter describes how to tune Oracle Adapters for optimal performance. Oracle Adapters, a component of the Oracle SOA Suite of Applications, provide an integrated view of data and allow multiple applications to be integrated.
This chapter contains the following sections:
Oracle technology adapters integrate Oracle Application Server and Oracle Fusion Middleware components such as Oracle BPEL Process Manager (Oracle BPEL PM) or Oracle Mediator components to file systems, FTP servers, database queues (advanced queues, or AQ), Java Message Services (JMS), database tables, and message queues (MQ Series).
For more information on Oracle Adapters, see Oracle Fusion Middleware User's Guide for Technology Adapters.
This section describes the various features available for scalability and performance tuning of Oracle File and FTP Adapters.The Oracle File and FTP Adapters provide knobs to throttle the inbound and outbound operations. The Oracle File and FTP Adapters also provide knobs that can be used to tune the performance of outbound operations. The Oracle File and FTP Adapters knobs are described in the following sections:
Note:For composites with Oracle File and FTP Adapters, which are designed to consume very large number of concurrent messages, you must set the number of open files parameter for your operating system to a larger value. For example, to set the number of open files parameter to 8192 for Linux, use the
ulimit -n8192 command
The Oracle File and FTP Adapters provide parameters that can be used to throttle the inbound operations. The table below describes the inbound throttling practices:
Default: 10000 (ten thousand)
|This parameter defines the maximum number of files that the inbound adapter would submit for processing on each polling cycle. For example, if your inbound directory has 1000 files and the
Defined in the Inbound JCA File.
Default: False (In this case, the global in-memory queue is used).
|If the value is
Defined in the Inbound JCA File.
Default: -1 (In this case, the adapter uses the global thread pool and in-memory queue)
|This parameter enables the Oracle File and FTP Adapters to create their own processor threads rather than depending on the global pool of processor worker threads for processing the enqueued files. This parameter partitions the in-memory queue and each composite application receives its own in-memory queue.
Defined in the Inbound JCA File.
The Oracle File and FTP Adapters provide parameters that can be used to throttle the outbound operations. The table below describes the outbound throttling practices:
Default: 20 (In this case, not more than 20 translations occur for a particular outbound scenario.)
|This parameter specifies the maximum number of translation activities that are allowed to start in parallel for a particular outbound scenario. The translation step during the outbound operation is CPU intensive and must be monitored as it might cause other applications or threads to starve. The maximum value is 100.
Defined in the Outbound JCA File.
The Oracle File and FTP Adapters provide parameters that can be used to tune the performance of outbound operations. The table below describes the outbound performance parameters:
|If the parameter is set to true, then the outbound Oracle File or FTP Adapter writes translated data to a staging file and later streams the staging file to the target file. If the parameter is set to false, then the outbound Oracle File or FTP Adapter does not use an intermediate staging file.
Defined in Outbound JCA File.
|If True, then the translation step is serialized using a semaphore. The number of permits for semaphore (monitoring the translation step) comes from
If False, then the translation step occurs outside the semaphore.
|This parameter is applicable only if
If True, then the translation step occurs in-memory (an in-memory byte array is created.)
If False, then the adapter creates an output stream to the target file (FTP, FTPS, and SFTP included) and allows the translator to translate and write directly to the stream.
The Oracle Database Adapter is pre-configured with many performance optimizations. You can, however, make some changes to reduce the number of round trips to the database, as described in the following sections:
Note:The tuning considerations in this chapter are listed for example only. Tuning parameters are specific to each deployment. Review you current usage and performance issues to determine which tuning considerations can improve performance.
Adapter performance is directly related to the number of round-trips to the database, and the network cost of each trip. If performance becomes an issue, and making modifications is appropriate for your deployment, consider tuning the following parameters:
Indexes can improve performance of selects, updates and deletes. Index all queried fields, such as the primary key and the MarkReadField of the LogicalDeletePollingStrategy, when polling. For MarkReadField specify a non-null MarkUnreadValue. Caution: An index on a column containing many nulls may revert to full table scans.
OptimizeMerge parameter allows the detection of XML elements for which no value was specified. The related columns are excluded from inserts and updates. Disabling this parameter generally improves performance, but there is one case where it could have a negative effect. If multiple rows are being passed in as a single XML, and each row has different columns set (user entered with many optional fields), there is no benefit from batch writing, as each insert or update is different.
MaxRaiseSize parameter indicates the maximum number of XML records that can be raised at a time to the BPEL engine. For example, if you set
MaxRaiseSize = 10, then 10 database records are raised simultaneously. On an inbound read, for example, you can set
MaxRaiseSize = 0 (unbounded) which means that if you read 1000 rows, you can create one XML with 1000 elements. These elements are passed through a single Oracle BPEL Process Manager instance. A merge on the outbound side can then take all 1000 in one group and write them all at once with batch writing. Use the
MaxRaiseSize parameter for publishing large payloads.
This property controls the number of records processed per transaction by each thread. If set to a large value such as 1000, turning on the
UseBatchDestroy option could have a negative impact on performance. Setting a large
MaxTransactionSize and a small
MaxRaiseSize could also have negative impact on performance. Consider maintaining up to a 10:1 ratio in a synchronous scenario. Ideally, you should consider increasing
MaxRaiseSize until it is a 1:1 ratio.
This property controls how the processed records are updated (ex:
LogicalDeleteStrategy). If set, only one update/delete is executed for all the rows that are part of that transaction. The number of rows in a transaction is controlled by the
MaxTransactionSize option. Note that this may not always offer an improvement because, by default, batch writing is used, which also ends up in a single round trip to the database.
Batch reading of one-to-many and one-to-one relationships is on by default. You can also use joined reading for one-to-one relationships instead, which may offer a slight improvement.
Delete Polling Strategy
Avoid the delete polling strategy because it must individually delete each row. The sequencing polling strategy can destroy 1000 rows with a single update to a helper table. Note that a
LogicalDelete is also better than Delete, as updates are typically faster than deletes. To maintain performance, however, ensure that you have indexed the table. If you have not indexed, you can keep the total number of rows small by using deletes. In some instances deletes may be faster as the cost of a full table scan is negligible.
Distributed polling enables you to configure polling for scalability. For more information, see "Scalability" in Oracle Fusion Middleware User's Guide for Technology Adapters.
On BPEL you can configure Database Adapter processes to be synchronous. You can also create sequential routing rules in Mediator. This can improve throughput in database-to-database scenarios, as there is less instance processing impact.
The insert operation is the most performant because it uses no existence check and has no extra performance impact associated with it. There are no reads, only writes. If you know that you are inserting most of the time, use insert, and catch a unique key constraint SQL exception inside your BPEL process, which can then perform a merge or update instead. To monitor performance, you can enable debug logging and then watch the SQL for various inputs.
Merge executes one extra SELECT per related table. The SELECT is used to determine whether each row should be inserted or updated. If the row is updated, the update performed is minimal. If no rows have changed, nothing is updated.
The adapter should also point to a tuned data source connection pool. Tuning the connection pool is important because creating and tearing down database connections can impact performance.
On the Attribute Filtering page of the Adapter Configuration Wizard you can choose which fields to map to the XML and vice versa. You can improve performance by deselecting columns that are not needed for your particular business case, especially large columns like LOBs.
If you are using the XSL functions to assign primary keys to records, consider using the built-in native sequencing support in the adapter. Sequencing support obtains and caches 50 keys at a time by default. Caching improves performance by reducing the number of round trips. The chunk size can be controlled incrementally by modifying the
sequencePreallocationSize connector property.
Do not use primary or foreign keys on the database
Using primary and foreign keys can impact performance. Avoid using them when possible.
JDBC Driver Class
The default JDBC driver class used to create the physical database connections in the connection pool is
oracle.jdbc.xa.client.OracleXADataSource. Changing the driver to
oracle.jdbc.OracleDriver may provide some performance improvement.
For more information on tuning the JDBC drivers, see "Third Party JDBC Driver and Database Connection Configuration" in Oracle Fusion Middleware User's Guide for Technology Adapters.
One method of performance optimization for
merge is to eliminate check database existence checking. The existence check is marginally better if the row is new, because only the primary key is returned, not the entire row. Due to the nature of merge, however, if the existence check passes, the entire row must be read to calculate what changed. Therefore, for every row to be updated, you see one extra round trip to the database during merge.Use check cache on the root descriptor/table and any child tables if A is master and B is a privately owned child. If A does not exist, B cannot exist. And if A exists, all of its child tables are loaded as part of reading A.
Note:One way to prevent merge from performing an existence check for every record, when you know that an insert is required, is to set the primary key to null.
This section describes performance tuning for Oracle Socket Adapter. Performance can be optimized for the Oracle Socket Adapter using Connection Pool if the socket server you are connecting to does not close the socket with each interaction. Connection pool lets you use a socket connection repeatedly, avoiding the overload of creating a new socket for each interaction.
Note:The Connection Pool feature is applicable to outbound interactions only. For more information on Socket Adapters, see "Oracle JCA Adapter for Sockets" in Oracle Fusion Middleware User's Guide for Technology Adapters
In order to enable the connection pool feature for the Oracle Socket Adapter, the
KeepAlive connection factory property must be set to
True. This connection property can be modified using the Connection Pool tab of Oracle WebLogic Server Administration Console.
For instructions on modifying the Oracle Socket Adapter connection pooling, see "Configuring Oracle Socket Adapter Connection Pooling" in Oracle Fusion Middleware User's Guide for Technology Adapters.
This section describes some of the properties that can be set for the Oracle SOA JMS Adapter to optimize performance. See "Introduction to the Oracle JMS Adapter" in the Oracle Fusion Middleware User's Guide for Technology Adapters for more information.
To improve performance, the
adapter.jms.receive.threads property can be tuned for an adapter service. The default value is 1, but multiple inbound threads can be used to improve performance. When specified, the value of
adapter.jms.receive.threads is used to spawn multiple inbound poller threads.
<service name="dequeue" ui:wsdlLocation="dequeue.wsdl"> <interface.wsdl interface="http://xmlns.oracle.com/pcbpel/adapter/jms/textmessageusingqueues/textmessageusingqueues/dequeue%2F#wsdl.interface(Consume_Message_ptt)"/> <binding.jca config="dequeue_jms.jca"> <property name="adapter.jms.receive.threads" type="xs:string" many="false">10</property> </binding.jca"> </service>
This section describes Oracle AQ Adapter tuning configurations.
To improve dequeue performance 'adapter.aq.dequeue.threads' property can be set for an adapter service. Default value is 1 but multiple inbound threads can be used to improve performance. The value of property 'adapter.aq.dequeue.threads' is used to spawn multiple inbound poller threads.
<service name="dequeue" ui:wsdlLocation="dequeue.wsdl"> <interface.wsdl interface="http://xmlns.oracle.com/pcbpel/adapter/aq/raw/raw/dequeue/#wsdl.interface(Dequeue_ptt)"/> <binding.jca config="dequeue_aq.jca"> <property name="adapter.aq.dequeue.threads" type="xs:string" many="false">10</property> </binding.jca> </service>
The Oracle MQ Series Adapter supports the scalability feature for inbound operations only. Oracle MQ Series Adapter provides the parameter to control the number of threads that dequeue the messages from the inbound queue.You must specify the following property in the.jca file:
In the example above N is the number of threads that you want to span to dequeue the messages from the inbound queue.