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A message is just a record in a database table which has a timestamp (which determines the ordering), and other fields.
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- Queues can be sent to directly or from topics
- A queue can shouldnt have the same name as a topic. If there is a topic with that name it will supercede the queue when messages are sent
- There is a built in folder for queues in grouper: <ATTRIBUTE_ROOT_STEM_CONFIGURED_NAME>:grouperMessageQueues.
- A queue is a permission resource in that folder of attributeDef <ATTRIBUTE_ROOT_STEM_CONFIGURED_NAME>:messages:grouperMessageQueueDef
- The action to send to a topic is "send_to_queue", grant that to a subject who is allowed to send messages to the queue
- The action to receive from a queue is "receive", grant that to a subject who is allowed to pull messages off the queue
| Code Block |
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grouperSession = GrouperSession.startRootSession();
GrouperBuiltinMessagingSystem.createQueue("abc");
GrouperBuiltinMessagingSystem.deleteQueue("abc");
// permissions on objects
GrouperBuiltinMessagingSystem.allowSendToQueue("abc", SubjectTestHelper.SUBJ0);
GrouperBuiltinMessagingSystem.allowReceiveFromQueue("abc", SubjectTestHelper.SUBJ0);
GrouperBuiltinMessagingSystem.disallowSendToQueue("abc", SubjectTestHelper.SUBJ0);
GrouperBuiltinMessagingSystem.disallowReceiveFromQueue("abc", SubjectTestHelper.SUBJ0); |
Setup topics
- There is a built in folder for topics in grouper: <ATTRIBUTE_ROOT_STEM_CONFIGURED_NAME>:grouperMessageTopics.
- A topic is a permission resource in that folder of attributeDef <ATTRIBUTE_ROOT_STEM_CONFIGURED_NAME>:messages:grouperMessageTopicDef
- The action to send to a topic is "send_to_topic", grant that to a subject who is allowed to send messages to the topic
- You cannot read from a topic, the topic will send to queues, and you can grant that on queues
- To setup the relationship between a topic and queue(s), setup a permission resource implied relationship between the topic and the queues
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grouperSession = GrouperSession.startRootSession();
GrouperBuiltinMessagingSystem.createTopic("def");
GrouperBuiltinMessagingSystem.deleteTopic("def");
// permissions on objects
GrouperBuiltinMessagingSystem.allowSendToTopic("abc", SubjectTestHelper.SUBJ0);
GrouperBuiltinMessagingSystem.disallowSendToTopic("abc", SubjectTestHelper.SUBJ0); |
Performance
- This system (with local HSQL database) can process (send / receive / acknowledge)
- 125 messages per second in one thread
- 312 messages per second in 10 threads
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| Column name | Description | Index | Foreign key |
|---|---|---|---|
| ID | db uuid for this row | ||
| HIBERNATE_VERSION_NUMBER | incrementing number so two updates dont occur at once (optimistic locking) | ||
| SENT_TIME_MICROS | microseconds since 1970 this message was sent (note this is unique for one jvm, this is probably unique across jvms, but not necessarily) | ||
| GET_ATTEMPT_TIME_MILLIS | milliseconds that the message was attempted to be received. If the message is not confirmed in a certain amount of time, the state will be set back to IN_QUEUE to try again | ||
| GET_ATTEMPT_COUNT | how many times this message has been attempted to be retrieved | ||
| STATE | state of this message: IN_QUEUE, GET_ATTEMPTED, PROCESSED | ||
| GET_TIME_MILLIS | millis since 1970 that this message was successfully received | ||
| FROM_MEMBER_ID | member id of user who sent the message | foreign key to grouper_members.id | |
| QUEUE_NAME | queue name for the message that it is delivered to (note, topics can send to multiple queues, which will duplicate the message) | ||
| MESSAGE_BODY | message body | ||
| ATTEMPT_TIME_EXPIRES_MILLIS | millis since 1970 that this attempt will expire before it is acknowledged. After it expires it will be delivered again when receive() is called |
See Also:
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