Message brokers
In this article:
Message brokers#
General information#
Automated RabbitMQ service in K2 Cloud allows you to quickly deploy and configure a message broker.
RabbitMQ is a popular open source message broker. It serves as an intermediary in the message transmission between information system components. Thanks to the broker, they no longer need to monitor message delivery status, resend messages or wait for the transmission to complete, since the broker solves all these tasks. Thus, you can improve overall system performance by reducing the number of jobs done by other system components and time spent on their execution.
RabbitMQ offers rich functionality for customizing and optimizing the messaging process according to the system needs. For example, you can use different protocols to send and receive messages, set up routing rules, specify message handling priorities, and more.
Thanks to a lot of messaging protocols supported, RabbitMQ can be used in multi-protocol systems. In particular, it supports AMQP (Advanced Message Queuing Protocol), MQTT (Message Queuing Telemetry Transport), STOMP (Streaming Text Oriented Messaging Protocol), and XMPP (Extensible Messaging and Presence Protocol).
In addition, RabbitMQ features high degree of reliability and availability. Built-in replication and clustering mechanisms allow you to create message-intensive HA systems.
K2 Cloud supports the following RabbitMQ versions:
3.8.30;
3.9.16;
3.10.0.
Before you begin#
To get started with the message broker service, follow these steps:
Create a project, if you don’t have one.
In the IAM section, create a user, add it to the created project, and assign the PaaSServicePolicy policy to it for granting the required privileges to work with PaaS services.
Note
If you want to give the user access to other cloud services, then add this user to the CloudAdministrators group. In this case, assigning the PaaSServicePolicy policy is not required.
Make sure that the project has all the required resources – subnets, SSH keys, and security groups. Otherwise, create them.
Read the recommendations on how to work with the service in the cloud.
Run RabbitMQ#
To launch the service, go to the Service store or Running services subsection, select the RabbitMQ service in the Message brokers tab and click Create.
The service launch procedure comprises the following stages:
Set the required network parameters:
The configuration of the cluster in which the service will be deployed. The following options are available for selection:
single-node (non-high-availability service);
three notes in one availability zone;
three nodes in three availability zones;
VPC where the service will be deployed.
Security groups to control traffic through interfaces of the instances on which RabbitMQ service will run.
Subnets where the message broker service will be deployed, or network interfaces through which cluster nodes will connect to subnets.
Note
To run the service in the selected VPC, you must first create a subnet in the preferred availability zone (in a configuration with one zone), or one subnet in each availability zone (in a configuration with three zones). In addition, the same volume types must be supported in the availability zones used.
Note
The ability to attach network interfaces may be useful, for example, when you need to recreate the cluster where the message broker has been deployed. If you delete a service, but do not delete attached network interfaces, you will be able to reuse them for connecting nodes of a new cluster to subnets, where the new cluster will be deployed. Thus, you can keep previous network settings, such as private IP addresses and security groups, rather than configure them again.
Internal and/or internet-facing load balancers when the three-node cluster configuration is selected (for details, see Load balancer management).
Set the configuration of one or more instances on which the message broker service will run.
Select the instance type and parameters of its volumes: type, size and IOPS (if available for a type).
In addition, you can specify an SSH key. In this case, after automatic service configuration, you will have SSH access to the respective instances.
Attention
We provide the option to connect to instances using an SSH key while the new RabbitMQ service is beta testing. This feature may be disabled in the future.
Set the main service parameters:
Service name – any unique name for the caching service.
Version.
Monitoring agent installation option. For centralized monitoring of a message broker service, deploy the Prometheus-based monitoring service first.
Monitoring service – The selection of a monitoring service is only available when the Enable monitoring checkbox is checked.
Monitoring labels — Optionally, you can set monitoring labels, which the installed monitoring agents will assign to the collected metrics (for details, see Using labels). Labels can only be set when the Enable monitoring checkbox is selected.
Logging agent installation option – For centralized PaaS service logging, first create a logging service. Once a PaaS service is created, you will be able to install logging agents manually only.
Logging service – The selection of a logging service is only available when the Enable logging checkbox is checked.
Logging tags – Tags are assigned to logs when the latter are imported by the logging service. They simplify search for the required logs. Tags can only be set when the Enable logging checkbox is checked.
RabbitMQ user password. It can be set manually or generated automatically.
Set the advanced settings, if necessary. Click advanced settings and enter the settings and their values.
Important
The specified settings will be a part of the service configuration and, therefore, will affect its operation. Add only the settings you really need.
Click Create.
Note
The service launching process usually takes 5 to 15 minutes.
Load balancer management#
For RabbitMQ service in a multi-node high-availability configuration, you can create an internal and/or internet-facing load balancer (for details, see load balancers). They automatically distribute incoming requests among cluster nodes.
Load balancers are created automatically; their parameters and associated resources cannot be changed. Information about the created load balancers, in particular their DNS names, can be found in the Load balancers tab on the service page.
Attention
A load balancer running together with a PaaS service can be deleted only on the page of this service.
Important
To run the internet-facing load balancer, give external access to HAProxy ports, which is denied by default. Add enabling rule for tcp/5000 port to the security group that was specified when creating the service.
Create a load balancer#
A load balancer for a message broker service can only be created when the service is in Running status. You can create one internal and one internet-facing load balancer per service.
Important
You can create an internal load balancer only if route propagation is enabled in VPC.
Go to PaaS Running services and open the Message brokers tab.
Find the desired service in the table and click the service ID to go to its page.
Open the Load balancers tab and click Create.
In the window that opens, select a balancer you want to create. If none has been created yet, you can create both internal and internet-facing balancers at once.
Click Create to complete the action.
Delete load balancer#
Load balancer associated with the service can only be deleted when the service is in Running status.
Go to PaaS Running services and open the Message brokers tab.
Find the desired service in the table and click the service ID to go to its page.
Open the Load balancers tab and click Delete.
In the window that opens, select a load balancer you want to delete. If two load balancers have been created for the service, you can delete both at the same time.
Click Delete to confirm the action.
RabbitMQ service configuration#
If you have not enabled monitoring and/or logging when creating the message broker service, or you want to disable them, you can do it when the service is in the Ready state. You can also change the password and advanced settings.
Note
To enable monitoring and logging, first deploy Prometheus-based monitoring service and ELK-based logging service.
Important
If an attempt to modify some settings fails, then the service will be reset to default ones.
To set up the message broker service:
Go to PaaS Running services and open the Message brokers tab.
Find the desired service in the table and click the service ID to go to its page.
Open the Parameters tab and click Modify.
In the window that opens, you can generate or set a new password and configure monitoring and logging (or disable them if they are already enabled).
To change the advanced settings, click Additional parameters. Then click Advanced settings and set the new settings and their values.
To save settings, click Modify.
Environment upgrade#
PaaS services are upgraded regularly. If you want the already installed RabbitMQ service to support new features, then upgrade its environment. For the current environment version, see the Information tab on the service page.
Note
All services with environment version 3_6 and higher support environment update. It is also available for some previously deployed services with environment version 3_5. To check if you can update them, use the API method DescribeService: the response should contain the common:update_environment
value in the SupportedFeatures list.
Important
If an attempt to update the environment fails, the service will be reset to the default one.
To update the environment version:
Go to PaaS Running services and open the Message brokers tab.
Find the desired service in the table and click the service ID to go to its page.
In the Information tab, click Update environment version.
In the window that opens, select the version from the list, to which you want to upgrade the current environment.
Click Update to change the version.
Deleting a RabbitMQ service#
Deleting the RabbitMQ service deletes all instances and volumes created with it.
You can delete the service using one of the following methods.
Go to the section PaaS Running services.
Open the Message brokers tab.
Find the service in the table and click on the icon .
If you want to use network interfaces in the future, for example, to recreate a service on the cluster with the same network parameters, then, in the window that opens, disable the Delete associated network interfaces option.
Confirm the action.
Go to the section PaaS Running services.
Open the Message brokers tab.
Find the service in the table and go to the service page.
Click :Delete in the Information tab.
If you want to use network interfaces in the future, for example, to recreate a service on the cluster with the same network parameters, then, in the window that opens, disable the Delete associated network interfaces option.
Confirm the action.