On this article, we’ll have a look at what Oracle superior queue is, discover a number of the use instances, and take into account frequent greatest practices whereas implementing queue.
Transient Overview of Oracle Superior Queue (AQ)
In a enterprise utility, many programs and apps work collectively to combine and alternate data. Oracle Superior Queuing permits asynchronous communication by sending and receiving the message. This permits the message to be seamlessly built-in and saved on the database construction degree.
Excessive availability, scalability, and reliability are all operational advantages of Oracle Superior Queuing. As the data is saved on the database degree DBAs and builders have full management over the message and its life cycle.
Significance of Messaging Techniques in Enterprise Purposes
Enterprise apps are sometimes giant and complicated applications which are distinctive to the group. This requires a excessive diploma of safety and scalability. Usually, in-house and externally acquired merchandise alternate data with one another to realize the supposed enterprise goal. Oracle Superior queue allows the message to be propagated in a dependable and safe method, because it inherits the messaging requirements, messages are by no means misplaced, because the messages are saved on the native database degree. This significantly is useful, when the apps talk outdoors of a corporation’s community to alternate and retailer the data.
Article Aims and Scope
This text goals to know the idea of Oracle Superior Queuing, its benefits, and the strategy to its implementation. Upon finishing this text, the reader needs to be geared up to grasp, apply, and convey some great benefits of Oracle Superior Queuing.
What Is Oracle Superior Queue?
Oracle Superior Queuing (AQ) is a message-oriented middleware that’s built-in into Oracle Database. It makes use of the capabilities of the Oracle database to maintain messages in persistent queues. It’s primarily designed for managing utility processes, dealing with small companies, and executing actions in response to particular occasions.
Historical past of Oracle AQ
- Oracle first included a complicated queue as a built-in characteristic in launch 8i.
- Oracle 9i additional enhanced AQ by enhancing efficiency, message expiration upkeep, and prioritizing messages within the queue.
- XML message assist, message transformation, and monitoring options have been all included in Oracle 10g.
- Multitenant structure and safety features have been enhanced in Oracle 12c
Key Options and Advantages of Oracle AQ
In a nutshell, excessive availability, scalability, reliability, and traceability are the principle options of queue knowledge. We are going to have a look at these options in depth:
- Oracle queues have been engineered to be each scalable and extremely performant, enabling it to successfully handle huge message volumes (CLOB/ RAW knowledge) and facilitate concurrent message processing. It makes use of parallel processing and partitioning, two scalability options of Oracle Database, to satisfy the calls for of demanding enterprise environments.
- AQ queue messages are reliable and long-lasting. As a result of they’re saved within the database, even within the case of system crashes or failures, they don’t seem to be misplaced. For mission-critical purposes the place knowledge integrity is significant, this dependability is important.
- It permits messages to be exchanged between purposes or between completely different areas of an utility with out requiring each events to be out there or actively current on the identical time.
- AQ gives the power to take care of message ordering inside a queue, guaranteeing that messages are dealt with within the order that they’re queued. For purposes the place a exact order of operations is required, this characteristic is essential (FIFO – First In First Out).
- Oracle’s superior queue can deal with a variety of message varieties, akin to textual content, XML, uncooked knowledge, and user-defined varieties. Due to this adaptability, builders can combine AQ with a wide range of utility architectures and work with a wide range of knowledge varieties.
- Messages will be assigned various ranges of precedence due to AQ’s assist for priority-based message queuing. Due to this characteristic, complicated message processing logic based mostly on message precedence will be applied.
- Monitoring and administration: By way of Oracle Enterprise Supervisor (OEM), a lot of database views, and APIs, AQ gives in depth monitoring and administration capabilities. Builders can simply handle queue configurations, observe message processing metrics, and regulate queue standing.
- AQ is engineered to be each scalable and extremely performant, enabling it to successfully handle huge message volumes and facilitate concurrent message processing. It makes use of parallel processing and partitioning, two scalability options of Oracle Database, to satisfy the calls for of demanding enterprise environments.
Comparability With Different Messaging Techniques (e.g., JMS, MSMQ)
There are different comparable messaging platforms out there within the Market particularly JMS (Jave Messaging System and Microsoft Message Queue). As a matter of comparability, we’ll see the first variations between them. This shall assist architects and builders in choosing or recommending essentially the most right platform.
Oracle AQ | JMS | MSMQ | |
Platform/ Atmosphere | Oracle | Java (It’s a platform-independent API) | Microsoft, Home windows platform |
Programming Language Assist | PL/SQL, Java, and different languages that may connect with Oracle | Primarily used with Java utility | .Internet languages |
Scalability | Oracle DB clustering | Dependents on the supplier and cargo balancing | Clustering and cargo balancing inside the Home windows atmosphere |
Mannequin | Helps each point-to-point (pointing to particular receiver) and publish-subscriber (pointed in the direction of a number of scribers) mannequin | ||
Compatibility | Tied with Oracle DB and works inside the Oracle atmosphere | Extra versatile and platform-independent | Tied with Home windows atmosphere |
Appropriate | If already having Oracle infrastructure, and appropriate when knowledge consistency and reliability are important | Platform impartial, versatile in choosing message suppliers the place integration is primarily with Java-based purposes | If the prevailing infrastructure is a Home windows server and suitable with .Internet applied sciences |
Message Mannequin rationalization through diagram
Choosing between Oracle AQ, JMS, and MSMQ is dependent upon the corporate’s present expertise framework, the necessity for scalability, the setting for deployment, and the anticipated want for future integration. Each messaging resolution gives distinctive benefits and is suitable for numerous conditions, contemplating these components.
Structure and Elements
Up to now, we now have understood, what’s oracle AQ, its historical past, advantages, and a comparability with comparable messaging programs or platforms. From right here onwards, we’ll take a deep dive into Oracle AQ structure and elements.
Oracle AQ Structure Overview
Now let’s see a high-level Oracle AQ architectural diagram.
Right here, the supply utility enqueues the messages, which Oracle AQ reads. As subscribers are registered the messages are dequeued into the goal utility
In response to the dequeued messages, the goal utility could or could not ship the response/acknowledgment again to the supply utility. Within the occasion of response messages, the goal utility sends the response to Oracle AQ by enqueuing the message in AQ and the supply utility dequeues the message to grasp the response on the goal system.
Be aware: Affected queues should be to register and subscribe to have the ability to ship and obtain the messages. Beneath the AQ Elements subject, we’ll see how queues will be registered and subscribed.
Now, let’s take one use case of Oracle AQ to have a greater understanding and the way it works.
Now we’ll see, what’s inside Oracle AQ.
In Oracle AQ we primarily have queues, queue tables, message processing, and propagation. Right here, exception queues are maintained to deal with any failover instances.
Additionally, you’ll discover that automated propagation will be set which permits the messages will be transmitted from one database to a different queue in the identical or completely different database. That is significantly, helpful for distributed purposes that are coping with a number of programs. Within the subsequent chapter we’ll see what core AQ elements are.
AQ Elements
As seen within the above diagram (architectural overview), the first elements of Oracle AQ are:
- Queue: Logical container for the payloads, A number of queues will be created based mostly on the applying necessities.
- Tables: Tables particularly designed for storing the payloads and metadata.
- Message: It’s precise knowledge transmitted via the queue; they sometimes have the data required for its consumption within the utility.
- Subscriber: Subscribers should be set to eat the messages out there within the queue. It may be an Oracle set off or a process.
Creating and Configuring Superior Queues
Earlier than creating queues, queue tables should be created. For a similar, chances are you’ll must work with the native DBA. DBA could must outline queue tables and handle permissions. To create queue tables, execute the under pattern SQL assertion.
CREATE TABLE my_queue_table(
queue_column1 datatype,
queue_column2 datatype,
... );
CREATE TABLE my_queue (
id NUMBER,
some_data VARCHAR2(100)
);
As soon as, queue tables are created, proceed with the creation of queues. Execute under SQL block under.
Be aware: The queue itself is a logical container for messages of a selected sort.
BEGIN
DBMS_AQADM.CREATE_QUEUE (
queue_name => 'queue_name',
queue_table => 'my_queue_table',
queue_type => 'NORMAL_QUEUE'
);
END;
As soon as queues are created, grants should be given to it, in order that, the required person(s) can have entry to it.
GRANT EXECUTE ON dbms_aqadm TO myuser;
GRANT EXECUTE ON dbms_aq TO myuser;
GRANT ENQUEUE, DEQUEUE ON my_queue TO myuser;
Enqueuing and Dequeuing Messages
Earlier than enqueuing or dequeuing the message, one should register and subscribe to the queues. After grants, ensure the subscriber for the queue has been registered in order that the message will be enqueued or dequeued. Consult with the SQL block under.
Choose depend(1) into w_subscr from dba_queue_subscription
The place queue_name = ‘my_queue’ and consumer_name = ‘udf_consumber’;
If (w_subscr ‘my_queue’
consumer_name = >‘udf_consumber );
Finish If;
Choose depend(1) into w_subscr_registrations from dba_subscr_registrations
The place subscription_name = ‘my_queue: udf_consumber’;
If (w_subscr_registrations = 0) Then
Dbms_aq.register( sys.aq$_reg_info_list(
sys.aq$_reg_info(
title => 'my_queue: udf_consumbe',
namespace => dbms_aq.namespace_aq,
callback => 'plsql://calling_trigger_to_setup_func_or_proc',
context => NULL) ), 1);
Finish If;
As soon as queues are registered and subscribed, let’s have a look at how the message will be enqueued or dequeued.
DECLARE
enqueue_options DBMS_AQ.ENQUEUE_OPTIONS_T;
message_properties DBMS_AQ.MESSAGE_PROPERTIES_T;
message_handle RAW(16);
BEGIN
DBMS_AQ.ENQUEUE (
queue_name => 'my_queue',
enqueue_options => enqueue_options,
message_properties => message_properties,
payload => 'That is my first AQ message',
msgid => message_handle
);
COMMIT;
END;
This may enqueue the message “This is my first AQ message” within the queue ‘my_queue’ Now, let’s have a look at how messages are dequeued. Be aware the block.
'plsql://calling_trigger_to_setup_func_or_proc'
Ought to name the code under.
DECLARE
dequeue_options DBMS_AQ.DEQUEUE_OPTIONS_T;
message_properties DBMS_AQ.MESSAGE_PROPERTIES_T;
message_handle RAW(16);
message_payload VARCHAR2(4000);
BEGIN
DBMS_AQ.DEQUEUE (
queue_name => 'my_queue',
dequeue_options => dequeue_options,
message_properties => message_properties,
payload => message_payload,
msgid => message_handle
);
DBMS_OUTPUT.PUT_LINE('Message dequeued: ' || message_payload);
COMMIT;
END;
Be aware: the payload messages are queued and saved in my_queue_table
and see that COMMIT
assertion is essential to maneuver to the subsequent message(s).
Superior Queue Options
Message Prioritization and Scheduling
Oracle Superior Queuing (AQ) offers you management over the timing and means messages are dealt with inside a queue by providing a lot of instruments that facilitate scheduling and message prioritizing.
You may give messages in a queue various levels of urgency or precedence by utilizing message prioritizing. Prioritization using message properties is supported by Oracle AQ.
Pattern SQL Block to set message precedence:
message_properties DBMS_AQ.MESSAGE_PROPERTIES_T;
message_properties.precedence := 1; -- Set the precedence of the message
Equally, for the messages to be dequeue, we will set a precedence/order by:
dequeue_options DBMS_AQ.DEQUEUE_OPTIONS_T;
dequeue_options.navigation := DBMS_AQ.FIRST_MESSAGE;
Message scheduling means that you can delay the supply of messages till a specified time or to schedule recurring deliveries of messages. That is achieved utilizing the enqueue_time
attribute within the message properties.
enqueue_time TIMESTAMP := SYSTIMESTAMP - 1;
Message Grouping and Batching
Message grouping and batching are significantly helpful after we wish to optimize and enhance efficiency. Group will be created on the time of queue creation. Messages belonging to 1 queue will be grouped to kind a set that may solely be consumed by one person at a time. This requires that the queue be created in a queue desk that’s enabled for transactional message grouping. This helps in categorizing messages based mostly on enterprise logic or processing necessities.
Each message in a bunch has a bunch or message ID and sequence quantity. To establish the message as belonging to which group or message. A set of messages that may solely be seen by one person at a time will be created by grouping messages from the identical queue. To perform this, the queue should be established in a queue desk with transactional message grouping enabled.
To know this, let’s assume, you’ve a number of exterior knowledge suppliers for comparable knowledge factors. You’ll be able to group them in a distinct queue desk. This may assist to trace and hint the messages acquired from the completely different knowledge suppliers and act accordingly.
Sending a number of messages directly in a single transaction or course of is called batching. This could improve throughput and decrease the overhead associated to performing quite a few separate duties.
- Batching will be applied on the enqueue and dequeue ranges.
- Utilizing queue arrays, a number of messages will be processed in bulk to scale back community site visitors.
- It might probably keep transaction integrity which makes certain that, messages are efficiently enqueued or dequeued.
Queue Monitoring and Efficiency Tuning
To ensure efficient operation and peak efficiency, Oracle queues, particularly these with Oracle Superior Queuing (AQ) — should be monitored and performance-tuned in a number of essential methods. Here is an entire technique:
- To ensure the queue is staying inside affordable bounds, periodically test its depth and dimension.
- To question queue statistics, together with the variety of messages (
NUM_MESSAGES
), the dimensions of the queue as of proper now (CURRENT_SIZE
), and the utmost dimension of the queue (MAX_SIZE
), use theDBA_QUEUE_TABLES
andDBA_QUEUES
views. - Monitor knowledge akin to common message dimension (
AVERAGE_MESSAGE_SIZE
), processing instances (ENQUEUE_TIME
,DEQUEUE_TIME
), and enqueue and dequeue charges (ENQUEUE_RATE
,DEQUEUE_RATE
). - To decrease the overhead of particular person transactions, use batch processing (
BULK ENQUEUE
andBULK DEQUEUE
). - To gather these metrics, use Oracle Enterprise Supervisor or customized scripts that question the
DBA_QUEUE_SCHEDULES
andDBA_QUEUE_SUBSCRIBERS
views. - Alter the transaction parameters (
DEQUEUE_BATCH_SIZE
,COMMIT_BATCH_SIZE
) to strike a steadiness between commit frequency and transaction dimension. - Monitor messages that fail to enqueue or dequeue on account of points by conserving a watch on the error queues (
DBA_QUEUE_ERRORS
). - Use Oracle efficiency instruments like AWR studies (
DBMS_WORKLOAD_REPOSITORY
) and ASH studies (DBMS_ACTIVE_SESSION_HISTORY
) to investigate queue-related efficiency metrics.
Integration With Oracle Streams and Oracle Goldengate
Superior queues will be built-in with each Oracle Streams and Oracle Goldengate to supply dependable and environment friendly knowledge integration and replication processes inside Oracle databases. Streams is a built-in characteristic of Oracle Database used for knowledge replication and messaging. Whereas, with real-time knowledge motion and synchronization throughout heterogeneous programs, Oracle Goldengate is a whole knowledge integration and replication resolution.
- Streams guarantee dependable message supply and consistency throughout distributed programs.
- It allows real-time propagation of messages and knowledge adjustments throughout the enterprise.
- It helps numerous knowledge codecs and kinds, making it suitable with completely different integration eventualities.
- Oracle AQ can act as a supply or goal for Oracle Goldengate, enabling bidirectional knowledge replication and synchronization.
Additionally, it helps integration throughout completely different platforms and databases past Oracle, enhancing enterprise knowledge integration capabilities and making extra appropriate choices for choosing Oracle superior queue.
Use Case and Eventualities
Up to now, we now have seen the in-depth of Oracle Advance Queue, lastly ramping up the guild with a use case and affected state of affairs, whereas choosing Oracle AQ.
- Occasion-driven structure for real-time knowledge
Enqueuing messages are saved domestically on particular occasions. Payloads are dequeued to course of and have an effect on downstream purposes or processes.
- Asynchronous Processing for decoupled purposes
Devices (funding securities) are getting opened parallelly through knowledge refresh from exterior knowledge suppliers. The processing of 1 safety is completely impartial of one other therefore in the true enterprise world there’s virtually no stoppage.
- Batch and Scheduling in a managed method
Enqueuing job requests into an AQ queue, the place a devoted job processing utility dequeues and executes jobs based on outlined schedules or priorities.
- Scalability and Load Balancing to deal with parallel processing and elevated load
Oracle AQ is successfully dealing with bulk and processing a number of payloads at a time.
Greatest Practices and Troubleshooting
- It is suggested to make use of computerized segment-space administration (ASSM) tablespaces for the AQ queue tables.
- The queue desk indexes, and index-organized tables (IOT)s are robotically merged by AQ background processes. Nonetheless, they have to proceed to be monitored and coalesced if wanted.
- Oracle Actual Utility Clusters (RAC) can be utilized to supply excessive availability and scalability to AQ. The efficiency of AQ will be improved by permitting completely different queues to be managed by completely different RAC cases.
- Make sure that there are sufficient queue monitor processes working to carry out the background duties. The queue monitor should even be working for different essential background actions.
- Make sure that statistics are being gathered in order that the optimum question plans for retrieving messages are being chosen. By default, queue tables are locked out from the automated gathering of statistics.
- Dequeue with a wait time ought to solely be used with devoted server processes. In a shared server atmosphere, the shared server course of is devoted to the dequeue operation at some point of the decision, together with the wait time. The presence of many such processes may cause extreme efficiency and scalability issues and may end up in impasse.
- Batching a number of dequeue operations on multi-consumer queues right into a single transaction, utilizing NEXT because the navigation mode if not utilizing message priorities, and utilizing the
REMOVE_NODATA
dequeue mode if dequeuing inBROWSE
mode adopted by aREMOVE
.
Conclusion
Oracle AQ supplies a stable basis for creating scalable, reliable, and event-driven purposes in Oracle Database environments, making it superb for a variety of enterprise use instances that require environment friendly messaging and knowledge integration capabilities.
AQ options like various service high quality, computerized message transformations, and propagations allow enterprises to create a strong and adaptable messaging platform. Database-integrated Superior Queuing allows real-time movement of important data, reduces administration, and boosts productiveness to your scalable, extremely out there group.
If the enterprise already has an Oracle platform, it’s extremely beneficial to make use of superior queueing on the enterprise degree to cater to numerous knowledge factors throughout completely different programs.
If the enterprise is doing a feasibility evaluation to pick out the right platform and atmosphere, they will actually take into account, Oracle and Oracle Advance Queue, as it should give them a strong, scalable platform on which the group can construct an IT panorama.