Istio, mTLS and the OSI layer

I have been playing a lot with Istio and recently tested mTLS encryption. The test, which I describe in this post, really materialized the OSI layer in front of my eyes. which is always interesting how new stuff can dust off your old basic knowledge.

The entire concept of service mesh and Istio is exciting and revolutionary in my view… but just like any new groundbreaking tech, it takes a few cycles to realize how it manifests beyond the papers, blogs and theory, at least for me. So, as I usually do, I share my experiences on this blog and in my sessions with other in the thought that if I can help even one person understand it better I have achieved my goal.
read more

Only I have the solution! and it is…

We live in a truly hyped era. Kubernetes, Docker, Istio, Serverless, PaaS, CaaS, FaaS you name the buzzwords, these words draw all the attention of the Dev/IT worlds, interstingly enough only a small percentage of organizations actually employ these technologies today, in production or even at all.

Like any new tech there are a barriers of knowledge and investment to get in, weighing the cost of moving to these platforms vs the pain it solves is hard to quantify. For each one of these trends and more that I may have forgotten, there is a group of followers who see these solutions as the be-all-end-all solution for every problem conceivable: read more

Service mesh is just another form of virtualization

When I started working with VMware ESX in the early 2000, I knew it was a very cool tech; and not only me, everyone knew there’s something special about it.

However, I haven’t fully grasped the full value of this technology right of the gate, at that point, I only saw “server consolidation” in front of me.

When vMotion came out, and we realized that physics has changed for our servers, we were no longer tied to the hardware the Server was running on. That hardware abstraction allowed us to do things we couldn’t do before. like fixing hardware issues or patch it with no downtime, scale much better and faster by deploying VMs when we need them and monitor the health of the infrastructure much better, even self heal. A new exciting world of agility we never saw before was opened.


Due to the above combined with automation, the effort of managing servers has been lowered, and fewer people are needed to manage fleets of servers.

What does that has to do with Service mesh you ask?

Recently I started focusing on Service mesh, mainly Istio, testing it in the lab, learning the technology and feeling that magic again. While the technology is cool, I was trying to understand the business value that is more than buzz words like distributed, load balancing, observability etc. However, at some point, I realized that I was looking at it all wrong. I was looking for the value from a networking operations point of view, it’s only when I looked at it from a developer value when it clicked.

Service mesh is a form of virtualization

When I get excited, I let the world know, that’s why I love twitter

I see much equivalency in Service mesh to virtualization.

In the monolithic app world, many of the different pieces of code that compile the application or service are running on a small set of servers, so making decisions about how that component interacts with other parts of the application are written in the code.

That means that for every piece of meaningful code that differentiates the business the application is servicing, need to have much non-differentiate code along with it.

Things like server and client side communication, service lookups, error detection and response, telemetry, security are taken care of in the code or middleware software.

With the rise of micro-services (and the use of containers for that purpose) each container now runs a piece of differentiating code and is a single purpose server that communicates with other services on the network. The distributed architecture and the proliferation micro-services, bring new challenges to manage, monitor and troubleshoot problems.


What service mesh and Istio does is outsourcing the non-differentiating work to the sidecars with Envoy where each k8s pod now has a proxy that is responsible for communicating with other proxies and out of the mesh. (Envoy can work with more than k8s pods, it can even work with VMs or Pivotal PAS AIs!)

Now we’ve abstracted the non-differentiating code. Similarly to the value we gained by virtualizing the hardware with the hypervisors and adding a control plane, we gain for the operations of the proxy by adding a control plane in the form of Istio (I will not go into the deeper architecture in this post, there are literally hundreds of posts about it out there)

Here is a diagram to illustrate the abstraction layers in one picture

We can apply our desired state as policies to anything that is not the core function of our software, change policies on the fly without changing our code which saves much effort spent by developers, dynamically changing the policies without changing any code, apply security and authentication to transactions and have better visibility into the application health. Self-healing becomes a real thing now.

But just like virtualization brought its own set of challenges, Service mesh is no different,  which I will cover in my next post.

You can read more about the details of Istio features in this blog post:

I think this analogy explains the subject, and the proliferation of abstraction layers brings a new set of challenges from a management point of view.

Have any thoughts on this? tweet your reply



NSX-T manager fails to load? It might be that the Corfu DB got corrupted

If you’re like me, and you are spinning new nested labs left and right, you are also probably over-committing on your VMFS datastore regularly.

The issue that happened to me was that I ran out of datastore space and it crashed my NSX-T manager. Perhaps this issue can also happen for other reasons. In any case the issue manifests itself by not being able to login to the NSX-T manager where it keeps saying that the service is not ready.

When runing the command “get management-cluster status” on the NSX-T manager you may get:

Number of nodes in management cluster: UNKNOWN

Management cluster status: INITIALIZING

Number of nodes in control cluster: UNKNOWN

This problem can heppn becuse the Corfu DB in NSX-T has failed to load. In the case of running out of datastore space it almost certainly a corruption in a record in the database. 

So how do we identify and resolve this issue?

Follow these steps:

  • ssh in to the NSX manager using user:admin
  • cd to /config/corfu/log/ directory. Here you should see the log files serially named. (example 280.log, 281.log,…)
  • Recommended to take a backup of the folder using cp -R /config/corfu/log/ /config/corfu/log.backup
  • In the appliance there is a log reader tool. use it to read teh latest log. e.g. corfu_logReader display <log file name> (example 281.log)
  • If the DB is corrupt the log (which might take a while to roll) will exit with an error. The output of this command will look something like the following:
  • read more

    What are these Spectre and Meltdown vulnerabilities all about

    For any of my friends that are not computer savvy, or usually don’t care. In this post I’ve digested the info for you about the security bug in CPUs, which is a BIG DEAL. You will start to hear the words like #Meltdown and #Spectre alot soon regarding your computer security. Allow me to explain in very high level, hopefully this helps some of you to better understand the biggest security bug in history :
    Meltdown is the name of a vulnerability found in Intel CPUs only, where 

    security is compromised to gain more speed. Basically Intel engineers designed their CPUs to be more performant but neglected to make sure they are secure enough, and the result is that one piece of code running on an Intel CPU can read the “kernel memory” of the operating system (OS) . Think of the kernel memory as your brain’s secret thoughts, what would have happened if I gained access there? In the computer world that’s where all your passwords are for example.
    The patches that are coming out for this one are on the OS side (windows, Linux etc) and they expect to slow down all Intel chip sets by 30%-50%. Yes, your computer will be slower.
    Do not underestimate this problem, code and guides how to exploit this vulnerability are already surfacing. (see link below)
    The second name you might hear is “Spectre”. This is a vulnerability that affects ALL cpu vendors. And the worst thing, this cannot be patched, it’s a basic design flaw and it will stay with us for at least a decade until the current HW cycle gets refreshed world wide. Fortunately this one is much harder to exploit. We will have to see how this rolls out.
    Most worrisome use case besides getting the password of your grandma back accounts, is shared HW, especially in the cloud. Think of one customer who rents compute resources from the cloud and is able to read password and data of other customers running on the same HW. Maybe your bank is the victim? And this affect everyone!
    That’s it, hope this helps, let me know your thoughts.
    Those who wants to read more see this link read more

    My VMworld sessions recordings from 2017

    This year’s VMworld was the most busy and unbelievably awesome I have been too. This year I was also extra busy myself with 3 Breakout sessions, including one with Microsoft PM on stage talking about our joint work together, that one unfortently was not recorded.
    Check the sessions recording out here:

    VIRT2211BU – Automating NSX for Virtual Machines and Containerized Applications

    VIRT1930PU – SQL Server on vSphere: A Panel with Some of the World’s Most Renowned Experts

    EU recording

    VIRT2211BU – Automating NSX for Virtual Machines and Containerized Applications

    My sessions recordings from VMworld US 2016

    It is so nice that VMworld has released the sessions recordings from VMworld US publicly for everyone, thanks to William Lam for publishing
    all the direct URLs here

    As for the sessions themselves, we had a nice turnout of about 220 folks in each session and the reviews were great.

    Here are the recordings:

    VIRT7575 – Architecting NSX with Business Critical Applications for Security, Automation and Business Continuity

    VIRT7654 – SQL Server on vSphere: A Panel with Some of the World’s Most Renowned Experts


    Have fun,


    My VMworld in 2016

    This is it, this year I am finally taking a very active role at VMworld after a few years of only being an attendee (except for one session at VMworld Europe in 2009 ) .

    For this year’s VMworld I am going to take on the role of the Booth captain for the Virtualzing apps track booth, (YES!)  I will be working with a staff of 4: Sudhir Balasubramanian, Vas Mitra, Agustin Malanco the man (Twitter – @agmalanco ) and Ryan DaWaele. such a great crew!

    We are planning 2 stations this year, where station #1 is going to run the traditional demos for Business critical applications with vSphere, features like: DRS, vMotion etc and new this year with vVols and vRA.

    Station #2 is new this year, we are going to have a second station solely focused on business critical apps with NSX demos. We are already working really hard on developing these demos so I don’t want to spoil it, but it is going to be epic! really cool stuff around Oracle RAC, SQL, SAP etc with really cool NSX demos. expect to be wowed.

    That’s not all, I have 2 sessions this year:

  • Architecting NSX with Business Critical Applications for Security, Automation and Business Continuity [VIRT7575] – A session covering the Business critical apps use cases with NSX where me and my colleague Sudhir Balasubramanian are going to cover the use cases to app owners and networking folks who are interested in applying NSX goodness to their app owners.
  • SQL Server on vSphere: A Panel with Some of the World’s Most Renowned Experts [VIRT7654] – I will be facilitating a panel of world renowned SQL Server experts about anything SQL on VMware. The panelists are:
    Denny Cherry, Twitter – @mrdenny Principal Consultant, Denny Cherry & Associates Consulting
    Allan Hirt, Twitter –  @SQLHA Managing Partner, SQLHA LLC
    David Klee, Twitter – @kleegeek  Founder, Heraflux Technologies
    Thomas Larock, Twitter  – @SQLRockstar  Head Geek, SolarWinds
  • read more

    VMware NSX Question – Can You Figure it Out?

    I wrote a blog post in the VMware official blog about a demo I recorded called “Dynamically enforcing Security On a Hot Cloned SQL Server With VMware NSX“.

    A bit long of a title but captures the essence of the demo perfectly. You can see the demo as well here:

    I got a question from a colleague of mine with has a very keen eye:

    “I just saw the great video you made, at 0:50 second of the demo we can see the rules for the prod app

    What is the meaning of rule 6?  If the source is the datacenter and is broader than the App Server in rule 5, and the rule allows for ANY service, doesn’t it make rule 5 irrelevant? “

    This is a great observation by Manuel with a very simple explanation which demonstrates perfectly the power of VMware NSX, can you figure out the answer?


    Rule 6 makes sense, only if you know your NSX 🙂



    Going For The Double

    I can’t believe i’m writing this post, I have achieved a second VCDX certification (or as it’s being referred to in the community a 2X 🙂 ). This time the design was for cloud (CMA) and it came just one year and some change after I became a VCDX DCV.

    Just being a VCDX was a long time career aspiration of mine and I am so grateful I was able to work on the second one.

    Short disclaimer – Since I am a VCDX panelist I am forbidden from mentoring candidates through their VCDX process or giving out advice on the design itself, this is so that I won’t give anyone an unfair advantage. I’ll keep this post about my personal experience towards achieving the double and keep the advice about the process.

    For this round I again worked with my partner from the first design Mr. Agustin Malanco (@agmalanco) where we designed a vRealize automation (vRA) on top of the previous DCV design.

    When we created the DCV design (which was factious just like this one) we intentionally designed it with cloud as  the next phase in mind. This is actually a recommended approach being discussed through the VCDX workshops as well, if you can create the first one planning ahead for the second do it.

    That doesn’t mean it wasn’t a lot of work, hell yeah it was!

    We spent nights and weekends for about 4 months, working out the design decisions, figuring out our process and installing the system to validate it and create the install guide.

    So, here are a few words of advice for anyone going for double :

  • If possible, when you are designing the first VCDX, plan ahead and build the foundation for the second and perhaps even the third.
  • In most cases when you are going for a second VCDX you only need to submit a design, there is no defense though there might be a phone interview that the reviewer will want some clarifications. That means your design will likely to be reviewed very carefully. Make sure your documentation is top notch. Remember, there is no second chance to defend it, after submission that’s it. note:
    • If your first VCDX was for non-vSphere NSX design if you submit for either CMA/DCV/DT design as your second you will need to defend again.
    • For top notch documentation refer to a previous VCDX article I wrote about the subject here.
  • If this is a fictitious design or partially fictitious validate the design by installing it in the lab.
  • This advice is true for the second VCDX as well as the first, if you can work in a team. It worked very well for me and Agustin.
  • read more