Active MQ load balancing to achieve high throughput - jms

Currently my activeMQ configuration (non persistent messaging) allows me to achieve 2000 msgs/sec. There are four queues and four consumers consuming the messages. There's only one activeMQ broker in this configuration. I would like to achieve a higher throughput of about 5000 msgs/sec (with addition of additional brokers). I'm pretty clueless on how to achieve this with out splitting individual queues on to individual ActiveMQ instances. What are the topologies that support higher throughput than the individual instance with out splitting the queues among instances ?

Adding a network of brokers might help. That is if you have a decent number of consumers and a decent number of producers connecting to different brokers.
If you have a single producer or a single consumer, all traffic will still go over one of the brokers, making it the bottleneck in any case. So, your actual setup of the servers using the AMQ broker is important.
You will also need to check what's the bottleneck of your physical machines. Is it I/O? CPU? Memory usage/heap size? Even Linkspeed? Use OS tools together with visualvm to track this down. Then you at least know what kind of server you need next.
In any case, some semi-manual load balancing is always possible over several nodes, weather you are using a network of brokers or not. Just make sure messages are routed through certain brokers depending on their content or whatnot. If you cannot distinguish between different message types in any logical way - you can do things like finding some integer number in the message (be it client IP, yesterdays temperature in celsius or whatever), and do a number modulo <num brokers>. Then route it to the destination you selected. Round robin is also an option. There is almost always a way to distribute the load in a logical way among several brokers.

Related

Redis vs Kafka vs RabbitMQ for 1MB messages

I am currently researching a queueing solution to handle medium sized messages of 1MB.
Besides the features differences between Redis, Kafka and RabbitMQ I cannot find any good answer to their performance on messages of size around 1MB.
Any of you guys knows how many messages of 1MB can any of these handle?
Do you know any other queueing solutions which can perform better?
When you are evaluating Kafka vs Redis in your case, there are other factors which you have to take into account, besides message size. Here are some of them I can think of:
How many producers/consumers? Redis performance can be affected in case of greater number of producers/consumers due to the nature of Redis (push based queue). This is because Redis delivers the message to all the consumers at once, at the moment the message is put in the queue.
Do you need speed or reliability first? If speed is of utmost importance, use Redis since it does not persist messages and it will deliver them faster. If you need reliability use Kafka since it persist messages even after they are delivered.
Do you want your consumers to get messages once they are ready or you want messages to be sent to the consumers immediately? In first case use Kafka because it's pull based mechanism (consumer have to ask for the message). In second case use Redis since it's push based mechanism (message is pushed to the consumer once it's on the queue). RabbitMQ is also push based (although there is pull API with bad performance)
What is the number of messages expected? If it's not huge use Redis since you are limited with memory. Otherwise use Kafka. Best practice for RabbitMQ is to keep queues short. This means that you can consume messages at the close rate at which they appear on the queue. So if you have some long lasting operation on the consumer part probably RabbitMQ is not the best choice.
Scaling? Kafka scales horizontally really well (it's built with scalability in mind). RabbitMQ is usually scaled vertically. Redis also scales well horizontally if needed.
It's obvious that there are more than one criteria when you evaluate proper queueing solution. There are best practices and recommendations for each of the queueing engines that you are looking at. Think more about your specific use case, it's definitely worth the time since it will save you time later on if you chose inappropriate queueing engine.
I am answering for Kafka.
Kafka itself has very good performance even for big messages.
In our tests with 2 Kafka nodes we reach p2p communication with 170 MB/sec smaller messages 150 MB/s bigger messages.
The only thing you need to remember is to configure the broker to accept bigger messages.
Hier is nice article: Configuring Kafka for Performance and Resource Management - Handling Large Messages
I know other p2p solution which might be interesting when you have concrete requirements look at YAMI4
I was using Redis but only for very small messages, so I cannot say anything about 1MB.

JMS with mandatory scalability (Active-Active-...-Active) and ordering?

I'm looking for a JMS provider that must have these additional characteristics:
Be multi brokers, where all brokers must be Active (no single point of failure)
Scalability on only two machines, would be sufficient for our needs
Be able to garantee ordering (if 1 producer + 1 consumer)
We have tried ActiveMQ 5.14, which seemed to be ok for both our requirements, but only when considered separately:
"ActiveMQ: To provide massive scalability of a large messaging fabric you typically want to allow many brokers to be connected together into a network so that you can have as many clients as you wish all logically connected together - and running as many message brokers as you need based on your number of clients and network topology. ... If you are using client/server or hub/spoke style topology then the broker you connect to becomes a single point of failure which is another reason for wanting a network (or cluster) of brokers so that you can survive failure of any particular broker, machine or subnet"
"Ordering: Total message ordering is not preserved with networks of brokers. Total ordering works with a single consumer but a networkBridge introduces a second consumer. In addition, network bridge consumers forward messages via producer.send(..), so they go from the head of the queue on the forwarding broker to the tail of the queue on the target. If single consumer moves between networked brokers, total order may be preserved if all messages always follow the consumer but this can be difficult to guarantee with large message backlogs."
Use Kafka, next generation distributed messaging as it is easy to scale out, offers high throughput, can persist messages to disk and ensure orderliness.
With kafka you can increase number of nodes to arrest node failure. If you can't remove JMS transfer messages as shown
JMS Producer(s) -> Kafka Cluster -> JMS Subscriber (s)
See Connection between Apache Kafka and JMS.

MassTransit selective consumers without round tripping

I am looking at using masstransit and have a need for selectively sending messages to consumers at the end if unreliable and slow network links (they are in the same WAN but use a slow and expensive cellular link).
I am expecting a fanout of 1 to 200 where the sites with lowest volume of messages and least reliable / most expensive links need to ignore the potentially high amount of message traffic othe consumers will see
I have looked at using the Selective consumer interface but this seems to imply that the message is always sent to all consumers, and then discarded if it doesn't match the predicate. This overhead is not acceptable.
Without using endpoint factory and manually managing uri end points to do a Send(), is there a nice way to do thus using subscriptions?
Simple answer: nope.
You do have a few options though. Is it just routing based upon load/processing? You could use competing consumers to do load balancing. All the endpoints read off the same queue (but they must be the same consumers on every process reading from the queue) and just pick up the next one. If you're slow, you just pick off fewer messages. (You can only use competing consumers with RabbitMQ).
For MSMQ there's a distributor that was built for load balancing. You could look at rebuilding that on top of RabbitMQ that if that's your transport. It's not super complicated, but would take some effort to do.
Other than that, I think you're likely down to writing something from scratch. It's not really pub/sub any more. So it falls outside MT's wheelhouse.

Low-latency, large-scale message queuing

I'm going through a bit of a re-think of large-scale multiplayer games in the age of Facebook applications and cloud computing.
Suppose I were to build something on top of existing open protocols, and I want to serve 1,000,000 simultaneous players, just to scope the problem.
Suppose each player has an incoming message queue (for chat and whatnot), and on average one more incoming message queue (guilds, zones, instances, auction, ...) so we have 2,000,000 queues. A player will listen to 1-10 queues at a time. Each queue will have on average maybe 1 message per second, but certain queues will have much higher rate and higher number of listeners (say, a "entity location" queue for a level instance). Let's assume no more than 100 milliseconds of system queuing latency, which is OK for mildly action-oriented games (but not games like Quake or Unreal Tournament).
From other systems, I know that serving 10,000 users on a single 1U or blade box is a reasonable expectation (assuming there's nothing else expensive going on, like physics simulation or whatnot).
So, with a crossbar cluster system, where clients connect to connection gateways, which in turn connect to message queue servers, we'd get 10,000 users per gateway with 100 gateway machines, and 20,000 message queues per queue server with 100 queue machines. Again, just for general scoping. The number of connections on each MQ machine would be tiny: about 100, to talk to each of the gateways. The number of connections on the gateways would be alot higher: 10,100 for the clients + connections to all the queue servers. (On top of this, add some connections for game world simulation servers or whatnot, but I'm trying to keep that separate for now)
If I didn't want to build this from scratch, I'd have to use some messaging and/or queuing infrastructure that exists. The two open protocols I can find are AMQP and XMPP. The intended use of XMPP is a little more like what this game system would need, but the overhead is quite noticeable (XML, plus the verbose presence data, plus various other channels that have to be built on top). The actual data model of AMQP is closer to what I describe above, but all the users seem to be large, enterprise-type corporations, and the workloads seem to be workflow related, not real-time game update related.
Does anyone have any daytime experience with these technologies, or implementations thereof, that you can share?
#MSalters
Re 'message queue':
RabbitMQ's default operation is exactly what you describe: transient pubsub. But with TCP instead of UDP.
If you want guaranteed eventual delivery and other persistence and recovery features, then you CAN have that too - it's an option. That's the whole point of RabbitMQ and AMQP -- you can have lots of behaviours with just one message delivery system.
The model you describe is the DEFAULT behaviour, which is transient, "fire and forget", and routing messages to wherever the recipients are. People use RabbitMQ to do multicast discovery on EC2 for just that reason. You can get UDP type behaviours over unicast TCP pubsub. Neat, huh?
Re UDP:
I am not sure if UDP would be useful here. If you turn off Nagling then RabbitMQ single message roundtrip latency (client-broker-client) has been measured at 250-300 microseconds. See here for a comparison with Windows latency (which was a bit higher) http://old.nabble.com/High%28er%29-latency-with-1.5.1--p21663105.html
I cannot think of many multiplayer games that need roundtrip latency lower than 300 microseconds. You could get below 300us with TCP. TCP windowing is more expensive than raw UDP, but if you use UDP to go faster, and add a custom loss-recovery or seqno/ack/resend manager then that may slow you down again. It all depends on your use case. If you really really really need to use UDP and lazy acks and so on, then you could strip out RabbitMQ's TCP and probably pull that off.
I hope this helps clarify why I recommended RabbitMQ for Jon's use case.
I am building such a system now, actually.
I have done a fair amount of evaluation of several MQs, including RabbitMQ, Qpid, and ZeroMQ. The latency and throughput of any of those are more than adequate for this type of application. What is not good, however, is queue creation time in the midst of half a million queues or more. Qpid in particular degrades quite severely after a few thousand queues. To circumvent that problem, you will typically have to create your own routing mechanisms (smaller number of total queues, and consumers on those queues are getting messages that they don't have an interest in).
My current system will probably use ZeroMQ, but in a fairly limited way, inside the cluster. Connections from clients are handled with a custom sim. daemon that I built using libev and is entirely single-threaded (and is showing very good scaling -- it should be able to handle 50,000 connections on one box without any problems -- our sim. tick rate is quite low though, and there are no physics).
XML (and therefore XMPP) is very much not suited to this, as you'll peg the CPU processing XML long before you become bound on I/O, which isn't what you want. We're using Google Protocol Buffers, at the moment, and those seem well suited to our particular needs. We're also using TCP for the client connections. I have had experience using both UDP and TCP for this in the past, and as pointed out by others, UDP does have some advantage, but it's slightly more difficult to work with.
Hopefully when we're a little closer to launch, I'll be able to share more details.
Jon, this sounds like an ideal use case for AMQP and RabbitMQ.
I am not sure why you say that AMQP users are all large enterprise-type corporations. More than half of our customers are in the 'web' space ranging from huge to tiny companies. Lots of games, betting systems, chat systems, twittery type systems, and cloud computing infras have been built out of RabbitMQ. There are even mobile phone applications. Workflows are just one of many use cases.
We try to keep track of what is going on here:
http://www.rabbitmq.com/how.html (make sure you click through to the lists of use cases on del.icio.us too!)
Please do take a look. We are here to help. Feel free to email us at info#rabbitmq.com or hit me on twitter (#monadic).
My experience was with a non-open alternative, BizTalk. The most painful lesson we learnt is that these complex systems are NOT fast. And as you figured from the hardware requirements, that translates directly into significant costs.
For that reason, don't even go near XML for the core interfaces. Your server cluster will be parsing 2 million messages per second. That could easily be 2-20 GB/sec of XML! However, most messages will be for a few queues, while most queues are in fact low-traffic.
Therefore, design your architecture so that it's easy to start with COTS queue servers and then move each queue (type) to a custom queue server when a bottleneck is identified.
Also, for similar reasons, don't assume that a message queue architecture is the best for all comminication needs your application has. Take your "entity location in an instance" example. This is a classic case where you don't want guaranteed message delivery. The reason that you need to share this information is because it changes all the time. So, if a message is lost, you don't want to spend time recovering it. You'd only send the old locatiom of the affected entity. Instead, you'd want to send the current location of that entity. Technology-wise this means you want UDP, not TCP and a custom loss-recovery mechanism.
FWIW, for cases where intermediate results are not important (like positioning info) Qpid has a "last-value queue" that can deliver only the most recent value to a subscriber.

Are there any tools to optimize the number of consumer and producer threads on a JMS queue?

I'm working on an application that is distributed over two JBoss instances and that produces/consumes JMS messages on several JMS queues.
When we configured the application we had to determine which threading model we would use, in particular the number of producing and consuming threads per queue. We have done this in a rather ad-hoc fashion but after reading the most recent columns by Herb Sutter in Dr Dobbs (in particular this one) I would like to size our threads in a more rigorous manner.
Are there any methods/tools to measure the throughput of JMS queues (in particular JBoss Messaging queues) as a function of the number of producing/consuming threads?
This is not really about a specific tool, but may be helpful.
Consumers:
Not sure what your inner architecture is, but let's assume it's an MDB reading in messages. I assert that your only requirement here for rigorous thread count sizing is to choose a maximum cap. If your MDB uses resources from a finite supplier like a JDBC connection pool, consider the maximum cap as the highest number of concurrent instances from that resource that you can tolerate taking. If the MDB's queue is remote, you probably want to consider remote connections (or technically, JMS sessions) a finite resource. If the MDB has less finite requirements (and the queue is local), your maximum cap becomes the number of threads, memory used and/or flat out CPU consumed by the working threads. The reasoning here is that the JBoss MDB container will simply keep allocating more MDB instances (and therefore threads) until the queue is empty or the maximum cap is reached. The only reason I can think of that you would really agonize over the minimum would be if the container's elapsed time or overhead to create new instances is above your tolerance and those operations are usually pretty small potatoes.
Producers
A general axiom of messaging is that producers nearly always outperform consumers. You would think this is pretty arbitrary, but it is a pattern I see recurring all the time, even in widely different messaging scenarios. Anyways, it's tough to say how the threading should work for the producer without knowing a bit about the application, but are you basically capable of [indefinitely] proportionally increasing the number of producer threads and the number of messages generated, or do you have some sort of cap where additional threads simply do not generate more messages ? I would guess it is the latter since most useful work has some limited data or calculation supplier. As I see it, the two drivers here are ordering and persistence.
First off, if you have strict message ordering where messages must be processed in strict (FPFP) First Produced First Processed then you're in a bit of a bind because you almost have to drop down to single threaded throughput unless you can devise some form of logical message demarcation (eg. a client number where any given client's messages are always sent to the same queue, but you may have multiple queues each serviced by one thread so each client is effectively FPFP).
Ordering aside, persistence is the next consideration in that if you have reliable and extensive message persistence, (or have a very high tolerance for message loss) just let the producer threads go to town. The messages will queue up reliably and eventually the consumers will [hopefully] catch up. However, if your message persistence message count or simple queue depths can potentially give you the willies when they get too high, here's where a tool might come in useful. If your producer thread count can be dynamically modified (which they can in many Java ThreadPool implementations) then you could sample the queue depths and raise or lower the producer thread count in accordance with the queue depth ranges you define, optionally to the point where if the consumers basically stall, so will the producers. I do not know of a specific tool that does this but between two JBoss servers this is fairly simple to whip up. Picking your queue depth-->producer thread count will be trickier.
Having said all that, I am going to actually read the article you linked to.....
I've got the perfect thing for you: IBM provide a free command line tool called perfharness.
It's aimed at benchmarking JMS providers, i.e. measuring the throughput of queues (single or multiple) given different numbers of producing or consuming threads.
Some features:
Send and consume messages at a fixed rate (msg/s) or at maximum rate possible on the queue
Use a specific number of threads
Use either JMS or native MQ
Can use data either generated randomly or taken from a file
Generates statistics telling you exactly how fast your queue is performing
The only down side is that it's not super intuitive, given the number of operations it supports. And IBM haven't open sourced it, which is a shame. However it sounds perfect for your purposes.

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