I wish to programmatically manage exchanges, queues, bindings, and view resource usage of my rabbitmq server. I can do all these by making REST API calls made available by rabbitmq management plugin. However, is it possible to achieve all that using AMQP protocol instead of using the management plugin? In other words, will an AMQP client allow me to do everything that the management plugin does?
If there is no alternative, is there any performance concern if I enable and use the management plugin?
In theory someone could implement a way that all the info is delivered via an AMQP queue. But it would have to be so that no consumer should ACK any of the messages because then they would be gone from the queue and the publisher would have to figure this out and publish the same thing again. In other words, it shouldn't be done.Also it would be semantically (?) wrong, since AMQP by it's nature is designed with flowing/changing/dynamic data in mind, and all this data about resources, queues etc is static (and in some cases meta) info.
No performance concerns (in this context of course).
Additionally you can also use the command line tool if it's more comfortable
AMQP 0.9.1 does not have any way of discovery or listing of queues and exchanges. Management plugin, on the other hand, has APIs such as GET /api/exchanges and GET /api/queues. Due to this requirement, management plugin was my only solution.
Related
Is not Apache Kafka another implementation of JMS?
I am using JMS+AMQ in my application, and migrating to Apache Kafka. Do I have to change all JMS codes?
No, Kafka is different from JMS systems such as ActiveMQ.
see ActiveMQ vs Apollo vs Kafka
Kafka has less features than ActiveMQ, as the stress has been put on performances. So before migrating, check that the features you use in AMQ are in Kafka.
However, there is an open suggestion for a bridge between JMS and Kafka, to allow exactly what you need. Maybe the provided links can help you
https://issues.apache.org/jira/browse/KAFKA-1995
Actually, the two are not the same. And with a little more time seeing the two co-exist - and listening to problems and happy points from those deploying each in the field - there is a little more to say about each one.
Firstly, JMS supports both point-to-point messaging (where messages are sent to single consumers; the consumers themselves maintain their message queues) and the publish-and-subscribe (pub/sub) model (where messages are written to a single topic, and consumers, independently, decide which messages to consume).
In a point-to-point messaging architecture, message producers and consumers know each other, where as in a pub/sub model they do not. Apache Kafka focuses on a pub/sub model, maintaining a separate log/topic from which consumers read from offsets. Kafka is also built for the cloud, with high-throughput a core consideration.
Many in our community and at meetups throw their hands up in frustration at MOMs (message-oriented middlewares) like JMS and switch to Kafka, for, what boils down to one reason: scalability. They argue that Kafka is better suited for scale than other MOMs because Kafka maintains a partitioned topic log. In so doing, Kafka can split up message flow to groups of consumers by partition and batch transmit the messages.
This concept also allows Kafka to have more granular control over ACLs (access control) to Kafka Consumers, although there are some issues there, which Apache Pulsar is addressing.
Finally, on Kafka, since the client/consumer decides which messages to consume (by offset in the topic), this removes some of the producer-side complexity of routing rules built into MOMs like JMS.
There's more differences than that, but this is a distillation of some of the ones that keep coming up! Hope this helps.
No, Kafka uses its own non-standard protocol and clients.
However, there's a 3rd-party JMS Client for Kafka from Confluent.
NServiceBus Distributor/Worker pattern makes perfect sense for MSMQ due to the hard requirement of local input queues.
But this is not the case with RabbitMQ, I am trying to understand how and when the NServiceBus distributor is relevant with RabbitMQ. With RabbitMQ multiple workers can read from the same remote queue.
The actual scenario is similar to using an AWS auto-scaling group to scale out workers pointing to a high available RabbitMQ cluster. Now avoiding distributor altogether makes the setup much simpler to build, test and provision.
Thoughts?
As RabbitMQ transport falls into the broker style bus, so, in your use case, it would make more sense not to use the distributor.
The same goes for all broker-style transports, where you can use a competing consumer pattern to scale out.
NServiceBus is an excellent system and does wonders in most message queuing system where you don't have an integrated distributor (which you do with exchanges in RabbitMQ). We use NServiceBus here at our company.
Azure Queues and MSMQ are perfect examples of such queuing technologies.
NServiceBus handles the distribution internally and therefore reproduces this capability for you.
However... If you are blessed with the possibility of imposing what queuing technology you can use, then I would highly encourage you to look into RabbitMQ and a product (Open Source) called MassTransit
http://masstransit-project.com/
MassTransit can in turn function in the two modes and will either delegate or simulate the distribution for you - however I nonetheless have a soft spot for NServiceBus as do our senior devs here.
Per this page...
http://docs.particular.net/nservicebus/load-balancing-with-the-distributor
Using the distributor is only useful when using MSMQ - if you aren't using MSMQ then there is no point. RabbitMQ and other transport will allow access to the same queue from multiple consumers, while MSMQ will not. The distributor in a nutshell will take messages from the main queue and distribute them across multiple worker queues as they report that they are done with whatever they are working on.
RabbitMQ supports multiple protocols, AMQP, MQTT, STOMP, ....
When using PHP for example, it's easier to publish using the STOMP library since the PHP AMQP libraries requires compiled C code and is somewhat of a mission to setup if you don't have to.
On the JAVA side, apache camel with AMQP on spring is pretty straight forward.
Is it possible to setup a queue, publish to it via STOMP and then consume via AMQP and then again publish via AMQP and consume via STOMP if the message broker is RabbitMQ?
Yes, this should work, given that you have installed RabbitMQ's STOMP plugin on your RabbitMQ node(s).
The protocol only defines the communication between client and server and has no impact on a message itself.
You should note that using protocols other than AMQP will most likely come along with limitations and/or worse performance.
There also exist native PHP libraries for RabbitMQ that don't require compiling C code. Unfortunately, I cannot tell you which one is the best, because I am a Java guy ;-).
I am wondering if there is a way to setup NServiceBus so that the machine actually getting the message from a publisher does not have the InputQueue on it. Also, I would like to publish to a general queue (though this can be accomplished with a web service.)
I am thinking I may use this to allow client machines to post and receive events. But the client machines are fairly locked down. If I need to have queues created on them I can, but it would be easier to have the queues uniquely named and in a more central location.
I am new to NServiceBus and pub/sub in general. So if I am off base on what I want please say so.
This sounds like the perfect candidate for an alternate queuing infrastructure beyond MSMQ--such as Azure Queues or Amazon SQS. With those types of queues you have no infrastructure to install on the client machines and everything is much more centralized.
Before you go down that road though, you'll want to get the basics of publish/subscribe under you. Pub/sub using MSMQ and NServiceBus has a decent learning curve to it and if you aren't familiar with how things work at that level then moving to cloud queues may be even more tricky.
I'm currently in the middle of developing a webapplication which needs a websocket connection to receive notifications of events from the server.
The clients are separated in groups and all the clients in a group must receive the same event notifications.
I thought that ActiveMQ could probably support this model, using different queues for each group of clients. It would also be relatively easy to push events to ActiveMQ using stomp, and then use stomp-over-websockets for the clients.
The problem I see is that messages should not be consumed by only one client, but distributed to all the clients connected to the queue.
Also the queue should not be stored. If a client is not connected when the event is generated, then it will never receive it.
I don't know ActiveMQ that much, so I'm not sure if this is possible or if there is another easy solution that could be used instead of writing my own message server.
Thanks
ActiveMQ 5.4.1 supports WebSockets natively (just like Stomp, JMS, etc.).
There is the concept of queues (you mentioned these), but also of topics.
In a queue, a single message will be received by exactly one consumer, in a topic
it goes to all the subscribers. See: http://activemq.apache.org/how-does-a-queue-compare-to-a-topic.html
There are some Stomp-WebSocket JS libraries floating around. Kaazing has a bundle that includes ActiveMQ and supports JMS API/Stomp protocol over WebSockets with support for older browsers, different client technologies, and Cross-Site security.
Look at Pusher, otherwise you'll need something that supports topic based pub/sub. You could look at Redis or RabbitMQ