Oracle Advance Queue - Dequeue not working
I can't seem to find the solution to my problem, I've been stuck at this for hours.
I'm usings Oracle AQs:
Dbms_Aqadm.Create_Queue_Table(Queue_Table => 'ITEM_EVENT_QT',
Queue_Payload_Type => 'ITEM_EVENT',
Multiple_Consumers => TRUE);
Dbms_Aqadm.Create_Queue(Queue_Name => 'ITEM_EVENT_QUEUE',
Queue_Table => 'ITEM_EVENT_QT',
Max_Retries => 5,
Retry_Delay => 0,
Retention_Time => 432000, -- 5 DAYS
Dependency_Tracking => FALSE,
COMMENT => 'Item Event Queue');
-- START THE QUEUE
Dbms_Aqadm.Start_Queue('ITEM_EVENT_QUEUE');
-- GRANT QUEUE PRIVILEGES
Dbms_Aqadm.Grant_Queue_Privilege(Privilege => 'ALL',
Queue_Name => 'ITEM_EVENT_QUEUE',
Grantee => 'PUBLIC',
Grant_Option => FALSE);
END;
Here's one of my subscribers:
Dbms_Aqadm.Add_Subscriber(Queue_Name => 'ITEM_EVENT_QUEUE',
Subscriber => Sys.Aq$_Agent('ITEM_SUBSCRIBER_1',
NULL,
NULL),
rule => 'tab.user_data.header.thread_no = 1');
Dbms_Aq.Register(Sys.Aq$_Reg_Info_List(Sys.Aq$_Reg_Info('ITEM_EVENT_QUEUE:ITEM_SUBSCRIBER_1',
Dbms_Aq.Namespace_Aq,
'plsql://ITEM_API.GET_QUEUE_FROM_QUEUE',
HEXTORAW('FF'))),1);
The subscriber registration:
Whenever a certain event occurs on my DB, I'm using a trigger to add "the event" to my AQ by calling the following procedure from my ITEM_API package:
PROCEDURE ADD_EVENT_TO_QUEUE(I_EVENT IN ITEM_EVENT,
O_STATUS_CODE OUT VARCHAR2,
O_ERROR_MSG OUT VARCHAR2) IS
ENQUEUE_OPTIONS DBMS_AQ.ENQUEUE_OPTIONS_T;
MESSAGE_PROPERTIES DBMS_AQ.MESSAGE_PROPERTIES_T;
MESSAGE_HANDLE RAW(16);
EVENT ITEM_EVENT;
HEADER_PROP HEADER_PROPERTIES;
BEGIN
EVENT := I_EVENT;
EVENT.SEQ_NO := ITEM_EVENT_SEQ.NEXTVAL;
ENQUEUE_OPTIONS.VISIBILITY := DBMS_AQ.ON_COMMIT;
ENQUEUE_OPTIONS.SEQUENCE_DEVIATION := NULL;
MESSAGE_PROPERTIES.PRIORITY := 1;
MESSAGE_PROPERTIES.DELAY := DBMS_AQ.NO_DELAY;
MESSAGE_PROPERTIES.EXPIRATION := DBMS_AQ.NEVER;
HEADER_PROP := HEADER_PROPERTIES(1);
EVENT.HEADER := HEADER_PROP;
DBMS_AQ.ENQUEUE(QUEUE_NAME => 'ITEM_EVENT_QUEUE',
ENQUEUE_OPTIONS => ENQUEUE_OPTIONS,
MESSAGE_PROPERTIES => MESSAGE_PROPERTIES,
PAYLOAD => EVENT,
MSGID => MESSAGE_HANDLE);
EXCEPTION
WHEN OTHERS THEN
ERROR_HANDLER.LOG_ERROR(NULL,
EVENT.ITEM,
EVENT.SEQ_NO,
SQLCODE,
SQLERRM,
O_STATUS_CODE,
O_ERROR_MSG);
RAISE;
END ADD_EVENT_TO_QUEUE;
And it's working because when I check my AQ table, I can find "the event", however my dequeue method is not dequeing, as you can see in the image bellow, there's no DEQ_TIME.
Here's my dequeue method, also from my ITEM_API package:
PROCEDURE GET_QUEUE_FROM_QUEUE(CONTEXT RAW,
REGINFO SYS.AQ$_REG_INFO,
DESCR SYS.AQ$_DESCRIPTOR,
PAYLOAD RAW,
PAYLOADL NUMBER) IS
R_DEQUEUE_OPTIONS DBMS_AQ.DEQUEUE_OPTIONS_T;
R_MESSAGE_PROPERTIES DBMS_AQ.MESSAGE_PROPERTIES_T;
V_MESSAGE_HANDLE RAW(16);
I_PAYLOAD ITEM_EVENT;
L_PROC_EVENT BOOLEAN;
O_TARGETS CFG_EVENT_STAGE_TBL;
O_ERROR_MSG VARCHAR2(300);
O_STATUS_CODE VARCHAR2(100);
BEGIN
R_DEQUEUE_OPTIONS.MSGID := DESCR.MSG_ID;
R_DEQUEUE_OPTIONS.CONSUMER_NAME := DESCR.CONSUMER_NAME;
R_DEQUEUE_OPTIONS.DEQUEUE_MODE := DBMS_AQ.REMOVE;
--R_DEQUEUE_OPTIONS.WAIT := DBMS_AQ.NO_WAIT;
DBMS_AQ.DEQUEUE(QUEUE_NAME => DESCR.QUEUE_NAME,
DEQUEUE_OPTIONS => R_DEQUEUE_OPTIONS,
MESSAGE_PROPERTIES => R_MESSAGE_PROPERTIES,
PAYLOAD => I_PAYLOAD,
MSGID => V_MESSAGE_HANDLE);
IF I_PAYLOAD IS NOT NULL THEN
L_PROC_EVENT := PROCESS_EVENT(I_PAYLOAD,
O_TARGETS,
O_STATUS_CODE,
O_ERROR_MSG);
END IF;
EXCEPTION
WHEN OTHERS THEN
ERROR_HANDLER.LOG_ERROR(NULL,
NULL,
NULL,
SQLCODE,
SQLERRM,
O_STATUS_CODE,
O_ERROR_MSG);
RAISE;
END GET_QUEUE_FROM_QUEUE;
Am I doing something wrong? How can I fix this? I think there might be a problem with my subscriber registration, but I'm not sure.
EDIT: I've just figured out that if I remove the subscribers and the register, and then re-add them, they'll dequeue all messages. Howerver if another event gets enqueued, it stays there indefinetly (or until I remove and add the subscribers again):
The record with state 0 and no DEQ_TIME is the new one.
Do I need a scheduler or something like that?
EDIT: I've added a scheduler propagation to my AQ:
DBMS_AQADM.SCHEDULE_PROPAGATION('ITEM_EVENT_QUEUE');
and even added the next_time field:
DBMS_AQADM.SCHEDULE_PROPAGATION('ITEM_EVENT_QUEUE', SYSDATE + 30/86400);
Still doesn't work. Any suggestions? I guess the AQ Notifications aren't working, and my callback procedure is never called. How can I fix this?
EDIT: I've removed my procedure from the package just for testing purposes, so my team mates can compile the ITEM_API package (I don't know if recompiling the package, may or may not have impacts on the dequeue process). Still doesn't work.
Answer
Create a code block and run the following:
DECLARE
dequeue_options DBMS_AQ.dequeue_options_t;
message_properties DBMS_AQ.message_properties_t;
message_handle RAW (16);
I_PAYLOAD ITEM_EVENT;
no_messages exception;
msg_content VARCHAR2 (4000);
PRAGMA EXCEPTION_INIT (no_messages, -25228);
BEGIN
dequeue_options.wait := DBMS_AQ.NO_WAIT;
dequeue_options.consumer_name := 'ITEM_SUBSCRIBER_1';
dequeue_options.navigation := DBMS_AQ.FIRST_MESSAGE;
LOOP
DBMS_AQ.DEQUEUE (queue_name => 'ITEM_EVENT_QUEUE',
dequeue_options => dequeue_options,
message_properties => message_properties,
payload => I_PAYLOAD,
msgid => message_handle
);
END LOOP;
EXCEPTION
WHEN no_messages
THEN
DBMS_OUTPUT.PUT_LINE ('No more messages left');
END;
Let me know what happens to your enqueued messages.
You should have a table where you're dequing the data.
Can you also try adding the enqueud table in the agent and then specify the agent to the dequeue table.
DECLARE
aSubscriber sys.aq$_agent;
BEGIN
aSubscriber := sys.aq$_agent('ITEM_SUBSCRIBER_1',
'ITEM_EVENT_QUEUE',
0);
dbms_aqadm.add_subscriber
( queue_name => 'ITEM_EVENT_QUEUE'
,subscriber => aSubscriber);
END;
/