Aws ec2 hostname

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This guide assumes familiarity with the general clustering guide as well the guide on cluster peer discovery. However, there are certain minor aspects to EC2 that need to be accounted for. They primarily have to do with hostnames and their resolution. RabbitMQ will work on every instance type, but there are a few considerations worth bearing in mind:. Although RabbitMQ is tested with most major Linux distributions, Ubuntu support for Amazon EC2 seems to be strongest, so that's the distribution this guide will use.

Those directories can be symlinks to a dedicated storage volume. The node must be stopped before symlinking is performed:. We recommend performing symlinking and other storage preparation steps before installing RabbitMQ when possible. If an EBS volume hits the limit, disk writes will worsen.

Amazon EC2 Instance IP Addressing

It is also possible that the RabbitMQ message store compaction garbage collection of on-disk data can fall behind disk writes, which means the disk will be filled up quicker than disk space can be reclaimed after messages were consumed and acknowledged. This will eventually lead to resource alarms and publisher throttling.

Several other guides cover topics highly relevant for running RabbitMQ clusters in public clouds:. 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.

If you'd like to contribute an improvement to the site, its source is available on GitHub. Simply fork the repository and submit a pull request. Thank you! All rights reserved. Terms of UsePrivacy and Trademark Guidelines. Choosing an Instance Type RabbitMQ will work on every instance type, but there are a few considerations worth bearing in mind: Use bit instances. Depending on the workload and settings, RabbitMQ can require substantial amounts of memory. Make sure that your host does have an appropriate amount of RAM and always have at least a few gigabytes of swap space enabled.

Workloads can be simulated using PerfTest. A separate guide on reasoning about node memory usage is available. RabbitMQ generally will take advantage of all the CPU cores in the system provided the workload uses multiple queues. Other factors should be taken into account e. Monitoring RabbitMQ nodes as well as applications that use it on real or simulated workloads will help assess how suitable a particular instance type is.

The node must be stopped before symlinking is performed: sudo service rabbitmq-server stop We recommend performing symlinking and other storage preparation steps before installing RabbitMQ when possible.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Server Fault is a question and answer site for system and network administrators. It only takes a minute to sign up. Am I missing a trick? To just set the hostname without Route53you can use cloud-init configuration in the user-data. This script can set the hostname, create a DNS record, and any other actions you desire. Sign up to join this community. The best answers are voted up and rise to the top.

Home Questions Tags Users Unanswered. How to boot EC2 with preset hostname? Ask Question. Asked 3 years, 9 months ago. Active 1 year, 7 months ago.

Viewed 7k times. Currently I manually go into a newly started Ubuntu Active Oldest Votes. To just set the hostname without Route53you can use cloud-init configuration in the user-data cloud-config hostname: mynode fqdn: mynode. Daniel Muller Daniel Muller 2 2 bronze badges. Thank you. No need to set hostname : "If both fqdn and hostname are set, fqdn will be used.

Perfect this was driving me crazy, thanks! I had been using user-data to run a script at boot but that's easy enough to accommodate by using a runcmd: section in the cloud-config yaml. Luckily my script is pretty basic but could see this being an issue if it were complex.

Is it possible to add an instance id to the hostname in cloud-config? Would be nice to see an example of this script. There are hundreds of bash script examples around the internet. Dig in and give it a try?

aws ec2 hostname

It seems that the user-data runs before the cloud-init sets the hostname? Sign up or log in Sign up using Google.

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AWS - How to map ip address with Domain name using AWS Route 53

Related January 08, None of its persists past a reboot. Which can make life very difficult for those planning to use EC2 for email or dozens of other tasks. Here's how to do it the right way, the first time. I'll also describe some circumstances that setting your own hostname will break things, and why its such a hassle to get this done in AWS in the first place. Amazon relies on cloud-init to manage a variety of initialization tasks for its cloud servers; cloud-init was originally built to support Ubuntu imagesbut it is now used for a variety of different Amazon distros, including RHEL, CentOS and "Amazon linux".

Think of it as a very fancy kickstart script. The hostname is viewable in the "Public DNS" column. Because of this behavior, all of the default methods for assigning a hostname to your server are over-ridden on reboot.

How do I assign a static hostname to a private Amazon EC2 instance running RHEL 7 or CentOS 7?

There is no way to change the hostname through the EC2 Console after your server has been built. Here's the part of the walk through where I describe some circumstances where messing with your hostname can break stuff. I haven't tried it, but I strongly suspect that making the changes in this walkthrough without an EIP will either just not work or will break something. There may be circumstances where you would want to accomplish this; hacks probably exist but this walkthrough ain't it.

Delete this value and replace it with your preferred hostname. The correct way is to just put your hostname in there; if you want your hostname to be www. Save and exit the vi editor. Type wq, and then press Enter to save changes and exit back to the command prompt. Change the entry beginning with Add the following string at the bottom of the file to ensure that the hostname change stays after a reboot. After you reboot your server, execute the hostname command to check that your changes have stayed put.

I ripped off most of this from an Amazon KB article on the topicwith a few updates where the KB had some mistakes. This has been an issue with AWS for a while, and there appears to be a lot of confusion on the internet on how to get this accomplished, so I hope that by making this available more people will be able to get this resolved without wasting time.

Post a Comment Dont spam.However, when I reboot or stop and then restart the instance, the hostname reverts to its former name. How do I get the new hostname to persist? To be sure that a hostname persists when an EC2 instance is rebooted or stopped, you must add the hostname to the appropriate configuration files on your EC2 instance. Replace persistent-hostname with the name you want the instance to use:. However, if required, you can manually edit this file to add the new hostname.

For general information about using the vi editor, run the command info vi from the command shell. Run the reboot command to reboot the EC2 instance and associate the new hostname with the instance:. Run the Linux hostname command without any parameters to verify that the hostname change persisted:. Changing the Hostname of Your Linux Instance. Last updated: Save and exit the vi editor. The command should return the new hostname that you specified in step 1.

Did this article help you? Anything we could improve? Let us know. Need more help? Contact AWS Support.If you've got a moment, please tell us what we did right so we can do more of it. Thanks for letting us know this page needs work. We're sorry we let you down. If you've got a moment, please tell us how we can make the documentation better.

When you launch an instance, it is assigned a hostname that is a form of the private, internal IPv4 address. Part of this hostname is displayed at the shell prompt when you log into your instance for example, ip Each time you stop and restart your Amazon EC2 instance unless you are using an Elastic IP addressthe public IPv4 address changes, and so does your public DNS name, system hostname, and shell prompt.

This information applies to Amazon Linux. For information about other distributions, see their specific documentation. This also changes the shell prompt so that it displays the first portion of this name instead of the hostname supplied by AWS for example, ip If you do not have a public DNS name registered, you can still change the hostname, but the process is a little different.

For Amazon Linux 2: Use the hostnamectl command to set your hostname to reflect the fully qualified domain name such as webserver. Log into your instance and verify that the hostname has been updated. Your prompt should show the new hostname up to the first ".

How do I change the hostname and from address on my Amazon EC2 instance when using AuthSMTP?

For Amazon Linux 2: Use the hostnamectl command to set your hostname to reflect the desired system hostname such as webserver. If you do not want to modify the hostname for your instance, but you would like to have a more useful system name such as webserver displayed than the private name supplied by AWS for example, ipyou can edit the shell prompt configuration files to display your system nickname instead of the hostname. For example, to set the system nickname to webserverrun the following command.

Edit the file and change the shell prompt variable PS1 to display your nickname instead of the hostname. Optional To set the title on shell windows to the new nickname, complete the following steps. The procedures on this page are intended for use with Amazon Linux only. For more information about other Linux distributions, see their specific documentation and the following articles:.

Javascript is disabled or is unavailable in your browser. Please refer to your browser's Help pages for instructions. Did this page help you? Thanks for letting us know we're doing a good job! Changing the Hostname of Your Linux Instance.

To change the system hostname without a public DNS name For Amazon Linux 2: Use the hostnamectl command to set your hostname to reflect the desired system hostname such as webserver. Document Conventions. Optimizing CPU Options.However, when I reboot or stop and then restart the instance, the hostname reverts to its former name. How do I get the new hostname to persist?

To be sure that a hostname persists when an EC2 instance is rebooted or stopped, you must add the hostname to the appropriate configuration files on your EC2 instance. Note: The following steps apply to Ubuntu Linux. For more information about the hosts file on Ubuntu, see the Ubuntu Type wqand then press Enter to save changes and exit vim.

Run the hostnamectl command and specify the new hostname. Again, replace the persistent-hostname with the new hostname.

aws ec2 hostname

After you restart or reboot the EC2 instance, run the Linux hostname command without any parameters to verify that the hostname change persisted. Changing the Hostname of Your Linux Instance. Did this page help you? Yes No. Need help? Short Description. If your EC2 instance uses IPv6, add the following configuration data. Save and exit the vim editor. The command should return the new hostname. Related Information. Published: Updated: By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

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I'm running a couple of standard Fedora instances on EC2. I feel the public hostnames of the instances assigned by Amazon are too weird and hard to remember. Is there any draw back in doing this? And how do I set it up such that it persists after reboots? Before you get started, try running hostname and hostname --fqdn and take note of what the responses are.

The bash prompt will change after you logout and login. Apache would then start but complained that it couldn't find the FQDN. I confirmed that running hostname --fqdn no longer worked. The FQDN of the system is the name that the resolver 3 returns for the host name. The DNS domain name is the part after the first dot. I also learned that a lot of amazon ec2 instances use something called cloud-init :.

aws ec2 hostname

User-data can be given by the user at instance launch time. This is done via the --user-data or --user-data-file argument to ec2-run-instances. I also found this which talks about how the hostname is configured with cloud-init:. The interesting takeaway is that if you don't change the hostname the cloud-init package will keep it up to date for you.

If someone else has a workaround or can address some of the issues mentioned and help reassure that nothing will break on ec2 instances because of changing the hostname I would be happy to hear it.

Edit: perhaps more correctly, machine-wide, e. From this site :. On any Linux system you can change its hostname with the command hostname surprised? Log into your instance and verify that the hostname has been updated.

Your prompt should show the new hostname up to the first ". Note: You can also change the shell prompt without affecting the hostname.

Refer to this AWS documentation.

aws ec2 hostname

Otherwise, you're pretty much stuck with the one they give you or an Elastic IP, if you set one of those up. In my Linux AMI a snapshot of other instance. If you don't want to mess with your DNS provider, you could use aliases for your instances.

I was really surprised that Amazon didn't provide a way to give an alias for an EC2 instance when they came out with the AWS Management Consolebut in the meantime, you could use the free RightScale service if you want the alias feature - much easier than remembering those Amazon instance IDs.

On my server all other services like apache and postfix works. Server is Ubuntu Learn more. Can we set easy-to-remember hostnames for EC2 instances? Ask Question. Asked 11 years, 1 month ago. Active 1 year ago. Viewed 67k times. Nikhil Gupte Nikhil Gupte 3, 4 4 gold badges 21 21 silver badges 15 15 bronze badges.


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