What is an Erlang cookie file?
The value is stored in a file commonly referred to as the Erlang cookie file. The cookie file used by the service account and the user running rabbitmqctl.bat must be synchronised for CLI tools such as rabbitmqctl.bat to function. All nodes in a cluster must have the same cookie value (cookie file contents).
What version of Erlang should I use in my RabbitMQ cluster?
RabbitMQ will check for internal protocol versions of Erlang and its distributed libraries when a node joins a cluster, refusing to cluster if there's a potentially incompatible combination detected. Outside of a reasonably long upgrade time window, it is recommended that all nodes use exactly the same version of Erlang.
Where is the RabbitMQ Erlang Cookie located?
The rabbitmq erlang cookie... ...will be typically located in /var/lib/rabbitmq/.erlang.cookie on Unix systems and C:\Users\Current User.erlang.cookie or C:\Documents and Settings\Current User.erlang.cookie on Windows systems.
Which cookie files need to be synchronised for RabbitMQ?
The cookie file used by the service account and the user running rabbitmqctl.bat must be synchronised for CLI tools such as rabbitmqctl.bat to function. All nodes in a cluster must have the same cookie value (cookie file contents).
Where is the Erlang cookie?
With Erlang versions starting with 20.2, the cookie file locations are: %HOMEDRIVE%%HOMEPATH%\.erlang.cookie (usually C:\Users\%USERNAME%\.erlang.cookie for user %USERNAME%) if both the HOMEDRIVE and HOMEPATH environment variables are set.
Why Erlang is used for RabbitMQ?
RabbitMQ will check for internal protocol versions of Erlang and its distributed libraries when a node joins a cluster, refusing to cluster if there's a potentially incompatible combination detected.
How do I check RabbitMQ cluster status?
Check the RabbitMQ cluster statusJoin the cluster, and restart the application on the third node.Execute rabbitmq cluster_status to see all 3 nodes: rabbit1$ rabbitmqctl cluster_status Cluster status of node rabbit@rabbit1 ...
How do I check my RabbitMQ connection?
Verify Server Configuration Here are the recommended steps: Make sure the node is running using rabbitmq-diagnostics status. Verify config file is correctly placed and has correct syntax/structure. Inspect listeners using rabbitmq-diagnostics listeners or the listeners section in rabbitmq-diagnostics status.
Does RabbitMQ require Erlang?
RabbitMQ requires a recent version of Python for generating AMQP 0-9-1 framing code. The Erlang development and runtime tools. On a Debian-based system then you need the erlang-nox, erlang-dev and erlang-src packages installed.
What is the purpose of Erlang?
Erlang is a programming language used to build massively scalable soft real-time systems with requirements on high availability. Some of its uses are in telecoms, banking, e-commerce, computer telephony and instant messaging.
How many nodes are in RabbitMQ cluster?
I have to say the official website provides very little information to understand RabbitMQ clearly. The official website suggests using three nodes to build a cluster.
How do I reset RabbitMQ queues?
RabbitMQ Management Interface Enter the queue tab and go to the bottom of the page. You will find a dropdown "Delete / Purge". Press Delete to the left to delete the queue.
What ports does RabbitMQ use?
By default, RabbitMQ will listen on port 5672 on all available interfaces. It is possible to limit client connections to a subset of the interfaces or even just one, for example, IPv6-only interfaces.
How many connections can RabbitMQ handle?
Below is the default TCP socket option configuration used by RabbitMQ: TCP connection backlog is limited to 128 connections.
What protocol does RabbitMQ use?
Advanced Message Queuing Protocol (AMQP)RabbitMQ is a lightweight, reliable, scalable and portable message broker. But unlike many message brokers familiar to Java developers, it's not based on JMS. Instead, your applications communicate with it via a platform-neutral, wire-level protocol: the Advanced Message Queuing Protocol (AMQP).
What is churn in RabbitMQ?
A system is said to have high connection churn when its rate of newly opened connections is consistently high and its rate of closed connection is consistently high. This usually means that an application uses short lived connections.
Why do we need RabbitMQ?
RabbitMQ is a messaging broker - an intermediary for messaging. It gives your applications a common platform to send and receive messages, and your messages a safe place to live until received.
What is RabbitMQ and how it works?
RabbitMQ is an open-source message broker software. It accepts messages from producers and delivers them to consumers. It acts like a middleman which can be used to reduce loads and delivery times taken by web application servers.
How do I create a connection in RabbitMQ?
In order for a client to interact with RabbitMQ it must first open a connection. This process involves a number of steps: Application configures the client library it uses to use a certain connection endpoint (e.g. hostname and port) The library resolves the hostname to one or more IP addresses.
Does WhatsApp use RabbitMQ?
The RabbitMQ is built on Erlang general-purpose programming language and it is also used by WhatsApp for messaging.
Introduction
This guide covers Erlang/OTP version requirements, Erlang version support policy , a RabbitMQ/Erlang compatibility matrix , version-specific notes and ways of provisioning recent Erlang/OTP releases.
Erlang Versions in Clusters
It is highly recommended that the same major version of Erlang is used across all cluster nodes (e.g. 22.x ).
HiPE (JIT Compilation)
HiPE support has been dropped in Erlang 22. RabbitMQ no longer supports HiPE precompilation.
Building Erlang from Source
If a sufficiently recent Erlang package is not available for a given operating system, Erlang/OTP can be built from source . This requires a build environment that satisfies the Erlang build dependencies, such as a modern OpenSSL version.
Getting Help and Providing Feedback
If you have questions about the contents of this guide or any other topic related to RabbitMQ, don't hesitate to ask them on the RabbitMQ mailing list .
Overview
This guide describes how RabbitMQ can be installed and configured manually on Windows. In general we recommend using one the more automation-friendly options for Windows when possible.
Install RabbitMQ Server
After making sure a supported Erlang version is installed, download rabbitmq-server-windows-3.9.10.zip.
Synchronise the Erlang Cookie
The Erlang cookie is a shared secret used for authentication between RabbitMQ nodes and CLI tools . The value is stored in a file commonly referred to as the Erlang cookie file.
Locating CLI Tools and App Data
Within the rabbitmq_server-3.9.10\sbin directory are some scripts which run commands to control the RabbitMQ server.
Running RabbitMQ Server as a Service
The service will run in the security context of the system account without the need for a user to be logged in on a console. This is normally more appropriate for production use. The server should not be run as a service and application simultaneously.
Checking Node Status
The following command performs the most basic node health check and displays some information about the node if it is running:
Default User Access
The broker creates a user guest with password guest. Unconfigured clients will in general use these credentials. By default, these credentials can only be used when connecting to the broker as localhost so you will need to take action before connecting from any other machine.
chebyshev
I've set docker container's environment variable HOME to /var/lib/rabbitmq so that the `rabbitmqctl` and broker will share the same cookie value.
chebyshev
According to the author's advice, I tried to run rabbitmq-server and rabbitmqctl under the same user `rabbitmq` and on the same container， the problem didn't go away .
Michael Klishin
There is a doc section that lists several scenarios that cover 99% of cookie-based authentication [1].
chebyshev
I have thoroughly read related official documents and it just indicates that the CLI tool's erlang cookie is not the same as broker's. That is just the case I encountered and other possible reason don't meet my situation.
Michael Klishin
but I failed to find any places in which RabbitMQ may append any new lines characters to the
Michael Klishin
With RabbitMQ 3.7.x you can also avoid relying on the runtime to load the cookie and do something like
chebyshev
Thank you for you patience. Finally I've solved this problem in my case.
What problem does RabbitMQ solve?
Before we delve into what RabbitMQ is and how to use it, it is worth learning more about the problem domain itself. Communication between different services (a.k.a computers) is an age-old problem.
Use cases
To show off the versatility of RabbitMQ, we are going to use three case studies that demonstrate how RabbitMQ is well suited as a black-box managed service approach, as one that integrates tightly with the application enabling a well-functioning micro-service architecture, or as a gateway to other legacy projects.
RabbitMQ as a general message-bus
When a monolith system is broken down to separate subsystems, one of the biggest problems that needs solving is which communication technology to use. A solution like Mulesoft, or MassTransit can “wire” services by declaring HTTP listeners and senders.
RabbitMQ as an advanced routing layer for micro-services
On the other end of the spectrum is an architecture which is more fluid and adapts to the ever-changing needs of many micro-services. What makes RabbitMQ shine in this environment is the very powerful routing capabilities it provides.
RabbitMQ integrated into legacy systems
In the previous use-case, I mentioned the possibility of using plug-ins to extend the functionality of RabbitMQ. This powerful feature allows RabbitMQ to act as a mediation layer between your RabbitMQ native (AMQP capable) services and other legacy applications.
Conclusion
As the above examples demonstrate, there is hardly anything that RabbitMQ can’t communicate with. But as with anything in life, it has a price. Although configuring RabbitMQ is mostly straightforward, sometimes the mere number of features can be overwhelming.
Debugging RabbitMQ
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Luke Bakken
Please use the latest versions of RabbitMQ and Erlang. You can find up-to-date Erlang binaries for Windows here - https://erlang.org/download/otp_versions_tree.html
Jorge Ribeiro
Thank you for your answer, but I have seen the documentation and I never find the cookie in the referred possible locations, when the service starts.
Luke Bakken
At this point you must help us help you. We don't have time to guess what may be wrong in your environment.
Jorge Ribeiro
I have tried copying the cookie that is created in the user home directory to the windows folder, to remove the service and install it again (with "rabbitmq-service remove" and "rabbitmq-service install") and to use the latest versions of both RabbitMQ and Erlang. The only way I could make it work was with the 64 bits version of Erlang.
Luke Bakken
Thank you for the rabbitmq-diagnostics status output. Please note that you did not provide all of the information I requested. In order to assist you, please do that from here on out.
Jorge Ribeiro
I followed the instructions as requested and below is the output of said commands.
Jorge Ribeiro
Ok, here goes attached the file with the text and all the log files from %AppData%\RabbitMQ.
