vSphere Integrated Containers – Affinity rules


Managing a vSphere environment is not about making use of the technology by itself, in fact, it's leveraging this technology to fulfill business needs what it really matters. Often vSphere Administrators utilize DRS affinity rules to control virtual machines placement specifying a group of hosts which might fulfill those needs, reasons vary from license constraints, specific hardware needs, increase availability etc.

With the advent of vSphere Integrated Containers, VIC, developers can instantiate their own containers, container-vms to be more precise, without the interference of a vSphere Admin, while it increases the agility of the business it also places a new challenge; as containers-vms come and go as need how admins can keep their affinity rules updated in order to fulfill the business need ??? For sure a manual intervention is not up for debate.

Luckily VIC 1.4 brought a new functionality, host affinity. When enabled, there will be a DRS VM Group for each Virtual Container Host, VCH, and as containers are created or deleted this group will be updated accordingly, helping administrators and developers life to adhere to those business need automatically.

During the creation of a VCH, you enable host affinity just specifying "--affinity-vm-group" option on the vic-machine command line (not yet available on VCH wizard).

A new DRS VM Group will be created with the same name of the VCH, you will also notice VCH VM is part of this group, it's made that way because it's impossible to create an empty VM Group, while an empty group can exist as a result of removing all VMs from it.

But what about new existing VCHs ???
Starting with VIC 1.4.1 you can reconfigure them enabling host affinity as well.
 
After creating the VCH, vSphere Administrators just need to create a VM-Host Affinity rule that matches this newly created VM Group and a Host Group, before handling the VCH for the developers.

So every time a developer creates or deletes containers on the VCH, the VM group membership will be updated accordingly and DRS will take care of the scheduling container-vm based on the rule create before automatically.
Enabling higher agility and improving operational efficiency while keeping the business need into account.

If you are still not sure why would you use this feature, I'd like to expose a few use cases;
On a hypothetical scenario of a single vSphere cluster made of 10 hosts distributed on 2 physical racks you may have;

*** Licensing needs ***
Let's imagine you have an application that is licensed per physical host or processor, to decrease your license cost you might create a host group containing just the hosts you have this application license for and match this group with an affinity rule for the VCH VM Group, this way you don't need to license your entire cluster;



*** Specific Hardware needs ***
Now if your container benefits from a graphical intensive processor, GPU, you can create a host group containing those hosts and match this group with the VCH VM Group, now those intensive containers will always be scheduled on the right host;



*** Fault Domains ***
Increasing your fault domain is always a plus when it comes to availability.
You can use a Host Group to create a kind of virtual cluster inside your vSphere cluster where the members of this host are spread among the racks. While you cannot guarantee your application will always be spread evenly between racks, HA will restart your container-vms on the remaining hosts in case of rack failure.



But, if you wanna make sure your application will always be spread evenly between racks you can create two VCHs, where each one will have an affinity rule to a Host Group based on hosts of a single rack.
Like VCH01 will use hosts from rack-A and VCH02 will use hosts from rack-B, now you can control the placement of your containers assuring that your application will always be available in case of a rack failure.


As you can see there's so many use cases for this feature but even more important is to support the agility you need while still aligned with your business need.

Do you have a different use case for this feature ? let us know...


via Latest imported feed items on VMware Blogs https://ift.tt/2urm50E
RSS Feed

If New feed item from https://blogs.vmware.com/feed, then send me an email at kr

IFTTT

Comments

Post a Comment

Popular posts from this blog

Evernote cuts staff as user growth stalls

Image
Note-taking app Evernote has fallen on hard times of late, culminating in its latest spate of job cuts impacting 15 percent of its workforce (54 employees). CEO Chris O' Neil -- an ex-Googler who took the reins in 2015 -- announced the firings at an all-hands meeting earlier today, reports TechCrunch . In a message on the Evernote blog , O' Neill admitted he'd set "incredibly aggressive goals" for the company in 2018. He continued: "Going forward, we are streamlining certain functions, like sales, so we can continue to speed up and scale others, like product development and engineering." The layoffs follow an exec exodus just weeks ago and the company's recent brand refresh (complete with a refined logo and wordmark). But critics are more concerned about its product, especially the free tier, which they claim lacks the perks to...
Read more

The best air conditioner

Image
By Liam McCabe This post was done in partnership with Wirecutter . When readers choose to buy Wirecutter's independently chosen editorial picks, it may earn affiliate commissions that support its work. Read the full article here . After six summers of researching, testing, and recommending window air conditioners, we've learned that quiet and affordable ACs make most people the happiest—and we think the LG LW8016ER will fit the bill in most rooms. This 8,000 Btu unit cools as efficiently and effectively as any model with an equal Btu rating, and runs at a lower volume and deeper pitch than others at this price. Little extra features like a fresh-air vent, two-axis fan blades, and a removable drain plug help set it apart, too. The LG LW8016ER is a top choice for an office or den, and some people will find it quiet enough for a bedroom, too. If our main pic...
Read more

We won't see a 'universal' vape oil cartridge anytime soon

Image
Pre-loaded cartridges of cannabis concentrate are currently among the most popular means of consumption, and for good reason. They're discreet to use and easy to handle, a far cry from the dark days of 2016 when we had to dribble hash oil or load wax into narrow-mouthed vape pens by hand. But, frustratingly, an ever increasing number of oil cartridge manufacturers employ one-off design standards so that their products won't work with those of their competitors, thereby locking customers into proprietary ecosystems. We've already seen this with nicotine vaporizers -- which has a seen a massive rise in "pod systems" in the last few years, each outfitted with a unique canister and battery built to be incompatible with those of their competition. Is it too late for the burgeoning cannabis industry to set a universal standard for their product designs? ...
Read more