Oracle AQ between 2 databases wont propagate - oracle

Question

I am trying to write a proof of concept to test sending/receiving messages between 2 Oracle database using AQ.
Source database : 12.1.0.2 SRCDB
Destination database: 19.14.0.0, DESTDB
We want to send a message from SRCDB to DESTDB, such that when DESTDB gets the message it automatically invokes a PLSQL stored procedure to dequeue and process.
So, start on the SRCDB I do the following:
CREATE OR REPLACE TYPE the_mesg AS OBJECT ( mesg VARCHAR2(20) );
/
`
BEGIN
DBMS_AQADM.CREATE_QUEUE_TABLE(
queue_table => 'the_que_tab',
queue_payload_type => 'the_mesg',
multiple_consumers => TRUE -- Mesg only consumed once ???
);
END;
/
-- create queue
BEGIN
DBMS_AQADM.CREATE_QUEUE(
queue_name => 'the_que',
queue_table => 'the_que_tab' );
END;
/
-- Add remote subscriber
DECLARE
reginfo SYS.AQ$_REG_INFO;
reginfolist SYS.AQ$_REG_INFO_LIST;
BEGIN
DBMS_AQADM.ADD_SUBSCRIBER(
queue_name => 'the_que',
subscriber => SYS.AQ$_AGENT( name => 'the)_sub',
address => 'the_remuser.the_que#destdb',
protocol => 0 ),
queue_to_queue => FALSE );
END;
/
-- Add propogation schedule
BEGIN
DBMS_AQADM.SCHEDULE_PROPAGATION(
queue_name => 'the_que',
latency => 0,
start_time => SYSDATE,
next_time => 'SYSDATE',
destination => 'destdb',
destination_queue => 'the_remuser.the_que' );
DBMS_LOCK.SLEEP(10);
END;
/
-- start queue
BEGIN
DBMS_AQADM.START_QUEUE(
queue_name => 'the_que',
enqueue => TRUE,
dequeue => TRUE );
DBMS_LOCK.SLEEP(10);
END;
/
-- propagation schedule
BEGIN
DBMS_AQADM.ENABLE_PROPAGATION_SCHEDULE(
queue_name => 'the_que',
destination => 'destdb',
destination_queue => 'the_remuser.the_que');
END;
/
-- Create send mesg wrapper procedure
CREATE OR REPLACE PROCEDURE send_mesg ( p_msg IN VARCHAR2 ) AS
l_enq_options SYS.DBMS_AQ.enqueue_options_t;
l_mesg_props SYS.DBMS_AQ.message_properties_t;
l_mesg_handle RAW(16);
l_mesg the_mesg;
BEGIN
l_mesg := the_mesg( p_msg );
DBMS_AQ.enqueue (
queue_name => 'the_que',
enqueue_options => l_enq_options,
message_properties => l_mesg_props,
payload => l_mesg,
msgid => l_mesg_handle );
COMMIT;
END;
/
-- Send mesg
EXEC send_mesg ( 'hello' );
Here, the queue's enqueue/dequeue settings are enabled, and there is an entry for the message in the queue table.
Then on the destdb:
CREATE OR REPLACE TYPE the_mesg AS OBJECT (
mesg VARCHAR2(20)
);
/
BEGIN
DBMS_AQADM.CREATE_QUEUE_TABLE(
queue_table => 'the_que',
queue_payload_type => 'the_mesg' );
END;
/
BEGIN
DBMS_AQADM.CREATE_QUEUE(
queue_name => 'the_que',
queue_table => 'the_que_tab' );
END;
/
DECLARE
reginfo SYS.AQ$_REG_INFO;
reginfolist SYS.AQ$_REG_INFO_LIST;
BEGIN
reginfo := SYS.AQ$_REG_INFO( 'the_remuser.the_que',
1,
'PLSQL://recv_mesg',
HEXTORAW('FF') );
reginfolist := SYS.AQ$_REG_INFO_LIST ( reginfo );
DBMS_AQ.REGISTER ( reg_list => reginfolist,
reg_count => 1 );
END;
/
BEGIN
DBMS_AQADM.START_QUEUE( queue_name => 'the_que',
dequeue => TRUE );
END;
/
CREATE TABLE mesg_table_aq_demo
(
cdate DATE DEFAULT SYSDATE,
mesg VARCHAR2(32) NOT NULL
);
CREATE OR REPLACE PROCEDURE recv_mesg
(
context IN RAW,
reginfo IN SYS.AQ$_REG_INFO,
descr IN SYS.AQ$_DESCRIPTOR,
payload IN RAW,
payload1 IN NUMBER
)
IS
l_deq_options DBMS_AQ.dequeue_options_t;
l_mesg_props DBMS_AQ.message_properties_t;
l_mesg_handle RAW(16);
l_mesg the_mesg;
no_messages EXCEPTION;
PRAGMA EXCEPTION_INIT ( no_messages, -25228 );
BEGIN
l_deq_options.msgid := descr.msg_id;
l_deq_options.consumer_name := descr.consumer_name;
LOOP
DBMS_AQ.dequeue ( queue_name => 'the_que',
dequeue_options => l_deq_options,
message_properties => l_mesg_props,
payload => l_mesg,
msgid => l_mesg_handle );
INSERT INTO mesg_table_aq_demo ( cdate, mesg )
VALUES ( SYSDATE, l_mesg.mesg );
COMMIT;
END LOOP;
EXCEPTION
WHEN no_messages THEN
NULL;
WHEN OTHERS THEN
RAISE;
END;
/
When I run this by enqueuing a message on the SRCDB the message is not propagated to the DESTDB.
No errors, although sometimes (as a result of desperate hacking) I see the following on the source user_queue_schedules:
ORA-25226: dequeue failed, queue SRCUSER.THE_QUE is not enabled for dequeue
Even though it looks like it is.
What am I doing wrong?