In order to describe what the message bus does in VMware NSX, we must first talk about what a message bus is. When...
By submitting your personal information, you agree that TechTarget and its partners may contact you regarding relevant content, products and special offers.
it comes to computer-to-computer communications, a host can use a protocol to access the other computer directly.
For example, one application might use an HTTP REST application programming interface call to initiate a process with an application running on another host. The problem with this is that the connection might fail if the host you are trying to access is unavailable or congested. In the event of a failed connection, the application running on the first host often won't restart.
A message bus creates a more robust system that can guarantee delivery of a specific message to a host, even if the host or application is temporarily unavailable. A message bus also allows the sender to specify what should be done with every message.
The message bus that NSX uses to communicate with vSphere is implemented with the Advanced Message Queuing Protocol (AMQP) with a RabbitMQ. AMQP is installed on the NSX Manager Virtual Appliance. As you can see in Figure A, the appliance allows you to verify whether RabbitMQ is running or not.
The vShield Firewall Daemon (VSFWD) sets up a connection to the message broker via Secure Shell on the ESXi host. The VSFWD processes and sends messages on behalf of other services on the vSphere host.
This process uses Transmission Control Protocol port 5671, so you can use the following esxcli command to verify whether a connection can be established between the RabbitMQ daemon and the one on the ESXi host:
esxcli network ip connection list |grep 5671
The NSX Manager uses the message bus to send information to the ESXi hosts, including policy rules, host certificates and keys needed to authenticate communication between hosts and controllers and more. The message bus is also responsible for handling requests to either create or delete distributed logical router instances. Firewall rules can also be transferred to the ESXi host through the message bus in a secure manner.
Making sense of NSX certification tracks
NSX's sphere of influence continues to grow
VMware puts muscle behind non-vSphere NSX
Dig Deeper on VMware and networking
Related Q&A from Rob Bastiaansen
Data center admins often run into problems when it comes to snapshot removal. The best way to avoid these issues is to prevent them in the first ...continue reading
There are a few ways to collect vSphere log files. If you have access to vCenter, you can use the vSphere Web Client.continue reading
The descriptor file plays an essential role in a virtual machine disk file, pointing to the larger data file and other VMDK information. So, what do ...continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.