How can I get copy of all messages (or references of all messages) that are on a VMQueue?
I want to loop through the list of messages that are currently on VMQueue, check the payload of every message, and based on that make decision about next step in the flow.
Thanks.
You have to consume them with a vm:inbound-endpoint, you can't peek or browse them without actually taking them out of the queue.
Related
Is there any API that can help me clear messages in all queues withing Artemis?
mbean: "org.apache.activemq.artemis:broker=\"1.1.1.1\",component=addresses,address=\"myaddressName\",subcomponent=queues,routing-type=\"multicast\",queue=\"myqueueName\""
operation: "removeAllMessages()"
type: "exec"
There's no programmatic way to simply delete all the data from every queue on the broker. However, you can combine a few management operations (e.g. in a script) to get the same result. You can use the getQueueNames method to get the name of every queue and then pass those names to the destroyQueue(String) method.
However, the simplest way to clear all the data would probably be to simply stop the broker, clear the data directory, and then restart the broker.
i was wondering if there is a way to implement metadata or even multiple metadata to a service bus queue message to be used later on in an application to sort on but still maintaining FIFO in the queue.
So in short, what i want to do is:
Maintaining Fifo, that s First in First Out structure in the queue, but as the messages are coming and inserted to the queue from different Sources i want to be able to sort from which source the message came from with for example metadata.
I know this is possible with Topics where you can insert a property to the message, but also i am unsure if it is possible to implement multiple properties into the topic message.
Hope i made my self clear on what i am asking is possible.
I assume you use .NET API. If this case you can use Properties dictionary to write and read your custom metadata:
BrokeredMessage message = new BrokeredMessage(body);
message.Properties.Add("Source", mySource);
You are free to add multiple properties too. This is the same for both Queues and Topics/Subscriptions.
i was wondering if there is a way to implement metadata or even multiple metadata to a service bus queue message to be used later on in an application to sort on but still maintaining FIFO in the queue.
To maintain FIFO in the queue, you'd have to use Message Sessions. Without message sessions you would not be able to maintain FIFO in the queue itself. You would be able to set a custom property and use it in your application and sort out messages once they are received out of order, but you won't receive message in FIFO order as were asking in your original question.
If you drop the requirement of having an order preserved on the queue, the the answer #Mikhail has provided will be suitable for in-process sorting based on custom property(s). Just be aware that in-process sorting will be not a trivial task.
I am receiving a large number of correlated HL7 messages in Mirth. They contain an ID which is always the same for all correlated messages and they always come within a minute. Multiple batches can be received at the same time. It's hard to say when the batch ends, but when there are no more messages for a minute, it's safe to assume that the batch has finished.
How could I implement an aggregator pattern in Mirth that would keep reading and completing correlated messages and send the completed message after it didn't receive any new messages with the same ID within a defined time interval?
You may drop all incoming message to a folder and store the message ID in a Global Map. Once new messages start to arrive with the message ID different than the one stored in the map (meaning that the next sequence is started), trigger another channel either by sending the message ID it needs to look for or in some other way. After that replace the message ID in the Global Map with the message ID of a new sequence.
If that sounds too complicated, you may do the same, but the second channel will constantly scan the folder (File Reader) and grab only files having the same message ID and older than a minute from a current time (which is in my mind is too vague qualifier).
I've implemented this by saving all messages in a folder using an ID inside the message (that identifies the sequence) as the file name. The file gets updated with each new message. Several sequences live together in the same folder.
The next channel is using a simple file reader that only fetches the files that are a minute or more old.
I am using the Azure REST API to read messages from an Azure Queue using Peek-Lock Message. Is there any way I can read the last message that was posted in the queue rather than reading from a queue based mechanism (FIFO)?
Also, is there a faster way to process messages from Azure other than using the Peek-Lock Message REST API?
Thanks!
Is there any way I can read the last message that was posted in the
queue rather than reading from a queue based mechanism (FIFO)?
Using the REST API, unfortunately there's no way to process the last message first. You would have to implement something on your own. If you know that your queue can't have more than 32 messages at a time, you could possibly get all 32 messages in one go and sort them on the client side based on the message insertion time. Yet another (crazy) idea would be to create a new queue for each message and name the queue using the following pattern: "q"-(DateTime.MaxValue.Ticks - DateTime.UtcNow.Ticks). Now list queues and get only the 1st queue. This will give you the message you last inserted.
Also, is there a faster way to process messages from Azure other than
using the Peek-Lock Message REST API?
One possibility could be to fetch more than one messages from a queue and process them in parallel on the client side.
I am using activemq to pass requests between different processes. In some cases, I have multiple, duplicate message (which are requests) in the queue. I would like to have only one. Is there a way to send a message in a way that it will replace an older message with similar attributes? If there isn't, is there a way to inspect the queue and check for a message with specific attributes (in this case I will not send the new message if an older one exists).
Clarrification (based on Dave's answer): I am actually trying to make sure that there aren't any duplicate messages on the queue to reduce the amount of processing that is happening whenever the consumer gets the message. Hence I would like either to replace a message or not even put it on the queue.
Thanks.
This sounds like an ideal use case for the Idempotent Consumer which removes duplicates from a queue or topic.
The following example shows how to do this with Apache Camel which is the easiest way to implement any of the Enterprise Integration Patterns, particularly if you are using ActiveMQ which comes with Camel integrated out of the box
from("activemq:queueA").
idempotentConsumer(memoryMessageIdRepository(200)).
header("myHeader").
to("activemq:queueB");
The only trick to this is making sure there's an easy way to calculate a unique ID expression on each message - such as pulling out an XPath from the document or using as in the above example some unique message header
You could browse the queue and use selectors to identify the message. However, unless you have a small amount of messages this won't scale very well. Instead, you message should just be a pointer to a database-record (or set of records). That way you can update the record and whoever gets the message will then access the latest version of the record.