问题
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.
回答1:
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;
/
回答2:
I faced the same problem, but it was solved after changing these 2 DB parameters:
- job_queue_processes (must be > than 0)
- aq_tm_processes (autotuning)
Hope it helps.
回答3:
We faced a related problem (at least related to the title), we couldn't dequeue messages with a delay. The messages in the queue stayed the state "WAITING". And were not changed to "READY".
The Oracle AQ monitoring process that is responsable for changing the state from "WAITING" to "READY" (after the delay is expired) wasn't working properly.
For us a database restart fixed this issue.
来源：https://stackoverflow.com/questions/30502535/oracle-advance-queue-dequeue-not-working