I am reading:
RabbitMQ Configuration
What is not clear is
When use rabbitmq.conf and rabbitmq-env.conf?
Especially when is mandatory use one over the other, it without matter in what OS (Windows, Linux, Mac) RabbitMQ is running.
I'm on linux and I use both.
In my system rabbitmq comes with pre-configured rabbitmq-env.conf. It would probably be enough if I was not clustering across multiple hosts (there is no rabbitmq.conf added to my /etc/rabbitmq by default).
As far as I understand (and I'm not rabbitmq expert) the rabbitmq.conf is to control some erlang based options. I personally use kernel options to bind rabbitmq to interface of my choice. But there is myriad of other things you can do there - in example you can configure rabbitmq to communicate over ssl and require all clients to authenticate using specific fields in their certificates. As far as I understand you cannot do that by using rabbitmq-env.conf.
rabbitmq-env.conf is used to set environment variables that are read upon startup docs. rabbitmq.conf is used to set things like TCP port, SSL certificates docs.
Environment variables (specified via rabbitmq-env.conf) are generally used to configure values that must be set prior to the start of the Erlang virtual machine - things like node name, the location of log and database files, etc.
NOTE: the RabbitMQ team monitors the rabbitmq-users mailing list and only sometimes answers questions on StackOverflow.
Related
I've come into an issue post install of Rabbit MQ where it was all set up and configured with the web apps on the machine and communicating to local applications however the machine had to be moved to a different tranch of machines and renamed as a result. Now Rabbit MQ can no longer serve or handle comms as intended as it's config points to rabbit#PREVIOUS_MACHINE instead of rabbit#CURRENT_MACHINE.
In the rabbit MQ config however, to complicate this, there was some configuration that was done from the users on the system that were fed into the local apps that are then encrypted into that local app's database and used for communicating with all the local apps. the issue here is if I drop and recreate Rabbit MQ a make a new user this won't align to what the other internal apps are using and I believe they are not configurable post install so a reinstall of everything is the potential impact.
the question is, is it possible to re-config or update the current RabbitMQ installation files to now point at the local machine name instead of the previous machine name AND I guess by proxy is this something that would even work. The docs over at rabbitmq don't quite deal with this specific scenario, unfortunately from what I've read through.
so i want to confirm that RMQ is the absolute dogs tits of a black magic box.
anyway,
following these steps from here minus the first two
How to change RabbitMQ node name without changing my hostname
this is the inverse of my problem pretty much. But for those in the future who have this issue;
I had Rabbit MQ on another machine installed and running, the machines name was changed and the solution was to uninstall the service, delete the db and reinstall the service. SOMEHOW rmq manages to keep the config knowledge of all the queues that were in the db in the system and when you reinstall the service it brings all the queues back as well. the only issue I had after that was to remember my username and password that were not default user set ups and I did so that solved my issue. still have no idea how RMQ manages to remember the previous configs despite deleting the local db, crazy cool. very grateful to whoever built that into the tool
We have a couple of crusty AWS hosts running a RabbitMQ implementation in a cluster. We need to upgrade the hardware, and therefore we developed a Chef cookbook to spawn replacement servers.
One thing that we would rather not recreate by hand is the admin users, the queues, etc.
What is the best method to get that stuff from the old hosts to the new ones? I believe it's everything that lives in the /var/lib/rabbitmq/mnesia directory.
Is it wise to copy the files from one host to another?
Is there a programmatic means to do this?
Can it be coded into our Chef cookbook?
You can definitely export and import configuration via command line: https://www.rabbitmq.com/management-cli.html
I'm not sure about admin user, though.
If you create new rabbitmq nodes on your new hardware, you will get all the users in that new node. This is easy to try:
run docker container with image of rabbitmq (with management plugin)
and create a user
run another container and add that node to the
cluster of the first one
kill rabbitmq on the first one, or delete
the docker container and you will see that you still have the newly
created user on the 2nd (but now master) node
I wrote docker since it's faster to create a cluster this way, but if you already have a cluster you could use it for testing if you prefer.
For the queues and exchanges, I don't want to quote almost everything found in the rabbitmq doc page for the high availability, but I will just say that you have to pay attention to the following:
exclusive queues because they are gone once the client connection is gone
queue mirroring (if you have any set up, if not it would be wise to consider it, if not even necessary)
I would do the migration gradually, waiting for the queues to get emptied and then kill of the nodes on the old hardware. It maybe doable in a big-bang fashion, but seems riskier. If you have a running system, than set up queue mirroring and try to find appropriate moment to do manual sync - but careful, this has a huge impact on the broker performance.
Additionally there is this shovel plugin (I have to point out that I did not use it or even explore it) but that may be another way to go since (quoting form the link):
In essence, a shovel is a simple pump. Each shovel:
connects to the source broker and the destination broker, consumes
messages from the queue, re-publishes each message to the destination
broker (using, by default, the original exchange name and
routing_key).
I am trying to setup a distributed system based on current spring-cloud release (meaning mostly Netflix OSS) using the following components
1 or more cloud config servers
1 or more Eureka servers
1 or more services using Eureka and Config Server clients
The setup above is easy enough to get going however once you start looking into setting up so that configuration changes in the cloud Config servers automatically trigger changes in the values of the actual clients, things start getting more complicated.
It is my understanding that for such a feature to work one should introduce spring-cloud-bus clients to the services which in turn will use, currently the only supported implementation, rabbitmq servers (the actual rabbitmq binaries and not some spring-boot app like eureka or Config servers) to allow change events in the Config server to be propagated to the clients automatically.
It sounds counterintuitive to setup such a system and have to hardcode addresses to rabbitmq servers in the clients (even if one will be keeping the amount of rabbitmq servers more or less static).
How is one supposed to register rabbitmq server instances in the Eureka service discovery server(s) to allow for clients to find them without having to have any knowledge about their location prior to startup?
I cannot seem to find any documentation on how this is done given that rabbitmq is not a spring-cloud component. In fact very little documentation seems to exist regarding on how the rabbitmq + eureka + spring-cloud-bus should be setup together.
I know that I am on a VERY old question, even though I think it worth a comment for people who read this in the future.
Most of the cloud services, lets take AWS as an example, have an Elastic IP solution - so you can configure IPs for RabbitMQ servers, and the IPs always belong to the RabbitMQ, no matter whether the instances change. You can re-attach the Elastic IP to different instances.
It works nearly the same with Elastic Load Balancer, which keeps its IP, so you could configure your microservices to a specific IP using Spring Cloud Config Server - and scale the RabbitMQ instances without a need to worry about configuration change.
I want to know if it is possible to run 2 versions (5.5 and 5.10) of ActiveMQ on the same machine. I simply assume that all I need to do reconfigure the ports on one of them to something different to the other.
The reason for this is that we are using Informatica B2B which uses ActiveMQ # 5.5 with a 3rd party (Fuse) addition for its internal messaging. We would also like to run a separate JMS server on the same machine for various reasons using 5.10 or 5.11.
I have found lots of examples of creating multiple instances, but they apply to using the same installation.
If it is that simple (as just changing the ports), can they also share the same JVM or not?
You can run multiple instances on the same machine by changing the ActiveMQ configuration. You should assign each Broker a unique name and configure the transport connector to listen on different ports. You also want to ensure that they are configure with different data directory instances and so on.
You cannot run two in the same JVN however.
I am confused about the function of Apache ActiveMQ.
I downloaded ActiveMQ from this link.
So I use it this way (environment: Windows 7): I start the bin/activemq.bat, then it works.
My question is: Does this mean I start a server on my machine? When I initialize the ActiveMQConnectionFactory, the broker URL is tcp://localhost:61616. But what if I want my machine to serve as a server and another machine to connect to my server?
Yes, you can use the primary box as a server and have consumers/subscribers running on other boxes (which will need to connect to the server - you will need to specify the server hostname & port for the connection to be established) - once in place, the messages on the server (topic or queue) can be consumed by the clients.
If you one have one producer and one consumer, you can look into using queues - if you have more than one consumer/subscriber, you can look into setting up a topic to which the consumers will subscribe to. Messages need to be inserted to the topic/queue as needed.
You can specify the server information in your code or preferably in the config file.
For reference to topologies:
http://activemq.apache.org/topologies.html
Also, you can choose to persist your messages or not based on your use case. Kaha DB is the preferred route (specially if performance is of concern).
Useful examples:
http://sujitpal.blogspot.com/2007/12/jms-patterns-with-activemq.html
http://vvratha.blogspot.com/2012/05/java-client-to-sendreceive-messages-for.html
Hope it helps.
Apache ActiveMQ ™ is the most popular and powerful open source messaging and Integration Patterns server
& it act like a third party server.
Apache ActiveMQ is fast, supports many Cross Language Clients and Protocols, comes with easy to use Enterprise Integration Patterns and many advanced features while fully supporting JMS 1.1 and J2EE 1.4. Apache ActiveMQ is released under the Apache 2.0 License.
ActiveMQ have the capabilities to send 100 MB single message framework and maintain 1000 concurrent connection simultaneously , for the further information you can check activemq.xml in your documentation.
Further Info at here about the ActiveMQ