How to learn Kubernetes ? “Kubernetes in action” the answer !

Few months ago I started the Manning Access Early Program (MEAP) for one of the books that I think is the best resource for all the newbies who want to start studying Kubernetes and for all the experts who want to dig into its details and internals.

It’s “Kubernetes in action” written by Marko Luksa , one of my colleagues in Red Hat as software engineer in the Cloud Enablement Team.

First of all, I can guarantee on the author ! Marko has a really deep knowledge of Kubernetes and OpenShift and luckily for us, he decided to write a book about that. He is a very nice person, always available to help you to solve any problem that you are facing with Kube. I was lucky to start working with Marko when the EnMasse project was born.

Speaking about the book, it’s awesome !

After the first part introducing Docker and Kubernetes and the first steps with it, the book moves to the core concepts.

You can find all information about what pods are and how you can deploy containers (so your applications) with them and finally how you can replicate pods. Then how to make applications accessible inside and outside the cluster using services and how to use storage for having a persistence layer for your data shared between pods and always available on restarts. Do you want to know how your application is configurable even with sensitive data (i.e. certificates and credentials), you will find such information in this book !

After covering all these core concepts, the last big part has the objective to bring you more deep information about Kubernetes. First of all, the new StatefulSets feature which allows to deploy stateful applications with their stable identity and stored data across restarts. Then a really interesting look to Kubernetes internals speaking about all the components which made it : etcd, the API server, the controller manager and all the other stuff. Managing resources is another interesting chapter describing how you can request specific resources in terms of CPU and memory for the containers even setting limits on them.

But one of the big advantage of using a container orchestrator like Kubernetes is the possibility to scale your infrastructure based on the load you have against the applications. You will find this information about auto-scaling on CPU utilization or custom metrics !

The final part is enriched by best practices for developing cloud native applications which run on Kubernetes. In order to learn a new technology, knowing how it works is the main part but it’s more useful having examples and patterns provided by expert people like Marko.

Finally, the book ends explaining how it’s possible to extend Kubernetes defining new components and custom API objects so showing a powerful feature like its extensibility.

In conclusion, I think that this book deserves to be read and to be part of your books collection even because after reading it you’ll become expert on two technologies for developing cloud native applications : not only Kubernetes but OpenShift as well ! 🙂


No winner in the (Industrial) IoT protocols war !

Yesterday, I read this article about declaring MQTT as the winner of the IIoT (Industrial IoT) protocols war and I have a completely different opinion on that so … I totally disagree with the author !

Don’t get me wrong, it’s not because I don’t like MQTT (who knows me, knows that I have done a lot of work around MQTT as well) but just because …

“There is NO winner in the (Industrial) IoT protocols war”

The IoT world is so rich of different use cases, scenarios, features needs and so on that most of the time, the better solution is an “hybrid” one which uses different protocols; even if you focus in the specific IIoT space, that’s true.

IoT has different communication patterns which come from the messaging land and every protocol provides support for one or more of them in different ways; sometimes we have builtin support, sometimes we need to do more work at application level.

MQTT for telemetry ? But …

MQTT fits really well for telemetry because it’s mainly based on publish/subscribe but at same time it has no flow control : what’s happen when the broker is overwhelmed by tons of messages at high rate and it can’t dispatch such messages to the subscribers at the same pace ? It’s even true that most of the time, MQTT devices are tiny sensors which send data with a slow rate (i.e. every second) because they are battery powered and use mobile connection so that they send a message, then go to sleep for few seconds and then wake up for sending the new message. In this case, you don’t have high rate but if you have thousands (millions ?) of these devices, the broker is overwhelmed as well : there is a burst of messages which come and it has to handle all of them.

AMQP doesn’t declare any specific supported pattern and it fits well for all. Regarding telemetry (so publish/subscribe), it provides flow control (even at different levels) so that the receiver node can stop the sender having more time for processing messages received up to now.

Why more complexity for Command & Control ?

Moving to command and control, so speaking about a request/reply pattern, all the MQTT limitations come. In this case, you have to build something on top of the protocol infrastructure defining specific topics for the requests and the related replies and having each client both subscriber (for receiving command) and publisher (for sending reply). There is no correlation between request and reply, it’s all defined at topic level (and/or using payload information).

With AMQP, even this pattern is supported natively. The requester has the possibility to specify a “replyTo” address inside the message, saying to the responder that it expects to receive the reply on such address; even the correlation is supported at protocol level thanks to message and correlation identifiers.

The real feature which makes this difference between AMQP and MQTT is that the former has message metadata (header, annotations and so on) while the latter has just payload (raw bytes) so all the features that it lacks for providing a different pattern from publish/subscribe need to be defined in terms of topics architecture and/or payload structure … so the complexity is moved at application level.

If you want to read more about these differences (even with HTTP protocol) maybe you can find my article “Strengths and weaknesses of IoT communication patterns” on DZone IoT as a useful reference (it’s part of the latest DZone IoT Guide).

Let’s say things as they are

The mentioned article says some wrong things as well.

“AMQP offers robust features like queuing” … to be precise there is no mention about queue in the AMQP specification but container, node, link and so on. This is because AMQP doesn’t specify the network architecture in terms of brokers : pay attention here, I’m speaking about AMQP 1.0 … the only OASIS and ISO/IEC standard (against the AMQP 0.9, used in RabbitMQ). AMQP can be used for RPC without “store and forward” mechanism (provided by brokers) but just with “direct” messaging; AMQP is a peer to peer protocol !

About MQTT … “An example of this optimization is its use of 1 byte keep alive packets.” … no true ! It’s 2 bytes ! … I know I’m a little bit pedantic here 🙂

Finally, it’s not true that only MQTT can work without high-availability and with a low-bandwidth. It’s true even for AMQP, considering the QoS (Quality of Service) levels it supports as well.

Speaking about messages size and computational needs on the devices side.

With MQTT each message carries the topic information, not true with AMQP where the address is specified one time on attaching the link.

When security and encryption come, the SSL/TLS overload minimizes all this differences so that even a 2 bytes packet for keep alive becomes an even bigger message. In this case, it all depends on computational resources you have on your tiny device and the difference between protocols doesn’t matter.


So my conclusion is clear. I have just started with that at the top of this article : there is no winner  in the (Industrial) IoT protocols wars. There are different use cases, scenarios, features needs, limitations … they all drive to the right choice that sometimes means having multiple winners in one solution !

The good news about MQTT is that in the latest v5 specification they are addressing a lot of limitations of the current 3.1.1 version, adding some AMQP-like features 🙂

So stay tuned … the war is endless !




Today meetup … “Open sourcing the IoT : running EnMasse on Kubernetes”

Yes … I’m at the airport waiting for my flight coming back home and I like to write something about the reason of my trip … as usual.

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Today, I had a meetup in Milan hosted in the Microsoft Office and organized by my friend Felice Pescatore who leads the AgileIoT project; of course my session was about messaging and IoT … so no news on that. The title ? “Open sourcing the IoT : running EnMasse on Kubernetes”.

Other friends were there with their sessions like Felice himself, Valter Minute speaking about how moving from an IoT prototype to a product and Clemente Giorio and Matteo Valoriani with very interesting sessions about Holo Lens real scenarios.

I started with an introduction about messaging and how it is related to the IoT then moving to the EnMasse project, an open source “messaging as a service” platform that is well suited for being the messaging infrastructure of an IoT solution (for example, it’s applicable inside the Eclipse Hono project).

I showed main EnMasse features and the new ones which will come in the next weeks and how EnMasse provides a messaging and IoT solution from an “on-premise” deployment to the “cloud” in a Kubernetes or OpenShift cluster. For this reason I said “open sourcing the IoT”, because all the components in such solution are open source !

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For showing that, I had a demo with a Kubernetes cluster running on Azure Container Service deploying EnMasse and Apache Spark on that. This demo was made of an AMQP publisher sending simulated temperature values to a “temperature” address deployed in EnMasse (as a queue) and a Spark Streaming job reading such values in order to process them in real time and getting the max value in the latest 5 seconds writing the result to the “max” address (another queue); finally an AMQP receiver was running in order to read and show such values from “max”.

If you want to know more about that you can find the following resources :

Yesterday DevDay meetup : “messaging” in Naples !


Yesterday evening I had the session titled “Messaging as a Service : building a scalable messaging service” during a meetup here in Naples speaking about the EnMasse project. The event was organized by the DevDay community which is active in my region in order to get in touch with developers who work with different technologies. I was very pleased to tell my experience (as a contributor) on developing a messaging service running “on premise” or in the cloud.



Following you can find the resources for this session :

  • the video published in the DevDay official YouTube channel
  • the slides and the demo code

Last but not least, I’d like to thank Davice Cerbo (from DevDay) who invited me to join the co-working space as guest during the day and setting up this meetup in the best way. Davide … keep up this great work for next events ! 😉

Let’s talk about EnMasse : the open source “Messaging as a Service”

After the Red Hat Summit speaking about JBoss AMQ and Apache Kafka using the EnMasse project, the coming weeks will be rich of sessions about this “Messaging as a Service” platform.

First of all, I’ll have a meetup on May 22nd in Naples organized by the DevDay community. It will be all around messaging (and I’m not going to speak about Whatsapp, Hangout, … :-)) and how we are developing a “Messaging as a Service” solution running on Kubernetes and OpenShift : it’s name is EnMasse.


The other session will be on June 5th in Milan during an IoT meetup organized by the AgileIoT community in the Microsoft House. There, I’ll always speak about EnMasse and how it “democratizes” the IoT giving you a full open source solution for that : in this case I’ll show how this “Messaging as a Service” platform can run in the Azure cloud as well.


So … if you want to know more about EnMasse just pick one of this events … or both ! 🙂


The “impact of an individual”

Monday 1st , 2017 … the alarm is ringing … it’s 3:00 AM … the time is arrived … let’s wake up … finally the Red Hat Summit is going to start !

After submitting my proposal and being accepted for a session with Christian Posta about JBoss AMQ and Apache Kafka … a few months have passed and one of the most thrilling experience in my work life is about less then 7000 kms far from me.

It’s 7:00 AM … the plane takes off and my mind starts to think about last year when, as a new hired, I was reading a lot of emails related to the Red Hat Summit materials and demo preparation from other “veteran” employees … I couldn’t imagine that after just one year I would have been one of the guys for the next summit !

Naples … Frankfurt … and finally Boston. I start to breath the summit just outside the airport with a lot of Red Hat advertising boards; the company has invested a lot of money and time for giving the best experience to employees, partners and customers in order to engage each other finding the way to collaborate and doing business but starting from something completely free … the freedom to think, to develop and to share ideas and projects with the community.

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Yes ! … because this is the Red Hat … no NDAs … no restrictions … no limits … it’s all up to you … you are completely free … free to propose, to design, to collaborate and … finally having an “impact as an individual” (cit.)


Yes ! … every person as an individual has his freedom and more individuals make a community developing ideas … becoming the biggest “company” in the world with million of developers. This is the way for innovation, no other way is the way to go. In such a model, every single person with a different experience and a different background can give his contribution to any open source project improving and enriching it. Every single person has an “impact as an individual” but for doing that he needs to be in the right context and Red Hat is the leading company on doing that.


After landing to the Logan airport I set my compass to the Boston Convention & Exhibition Center with my new friend Bolek; I have never seen him, it’s the first time we meet in person even because he doesn’t come from my messaging team but from the Keycloak one. This is one of the great things of this kind of big conferences; you’ll meet a lot of colleagues, customers, partners or community members from all around the world sometimes for the first time even if you chat with them almost every day. During this summit I’ll be in a shared accommodation with other two guys from the Keycloak team, Sebastien and Bruno, other than one of the “gurus” of my team, Ted.

The venue is huge, people are coming for the checkin or the onsite registration and the staff is building the partners pavilion; it must be ready for the coming day … and it will be !

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Let’s the summit begin ! A lot of speakers, from Red Hat and other companies, are bringing their knowledge and experience here with a common denominator … sharing what they are doing in the “open” way. Two keynotes every day and each one packed; all the rooms for the breakout sessions will be packed as well.

Announcements on JBoss AMQ 7, OpenShift, RHEL, Microservices and all the other projects and related products make the attendees so enthusiastic because there are a lot of things to do. New projects will come so let’s “start something” (cit) in the right way … “try, learn & modify” (cit.).


New announcements with “old” partners like Amazon, consolidation with other partners like Microsoft and experiences from big customers like Deutsche Bank. They trust us … they trust the way how Red Hat is the only company able to make an open source project reliable and usable at the enterprise level.

Attending the David Ingham and Ted Ross sessions around JBoss AMQ 7 make me so proud to be part of this team. They have been working so hard in the last years for bringing customers a new powerful experience doing messaging : the new broker, the new router component and the new clients. If you need to do messaging in your business there is no choice : from the hybrid to the cloud, AMQ 7 is the answer. And let me say that it will be even the pillar for the coming “baby” that is on its way : trust me … “incredible” guys are working on that, EnMasse is its name … the “messaging as a service” platform of the future.

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The IoT business is something that a lot of customers are exploring too and the “IoT Codestarter” evening event organized together with the Eclipse Foundation and Eurotech (our partner) is a great opportunity for hacking from the field with sensors and gateways to the Cloud : Kura and Kapua are the involved projects but I can say … pay attention to Hono as well (not only just because I’m working on that ;)).

On my side, the last day, when it seems that all the people are tired and want just to come back home, the room is packed. Why to use JBoss AMQ 7 ? When to use Apache Kafka ? Can I use them together ? I and Christian give the answers to these questions to the attendees. Even in this case, a lot of interest around that … “playing” around Kafka is on our radar (while I’m writing, this session has raised a lot of discussion on Twitter as well).

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Last but not least during these days I’m falling in love with Boston day by day; it seems to be ten or more cities into only one. Walking through the city and longside the river is a great experience.

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Three days have passed, all the Red Hatters and the other attendees are leaving Boston with a new freshness and the certainty that more great things are coming. What does it mean ? The countdown to the next summit is already started, San Francisco will wait for us, let’s see how every person will have his “impact as an individual” during this year.

This is the open source, this is Red Hat, this is the summit … something that you can breath every day which makes you part of a big community where the power, as I like to say, is always in the “collaboration” !

IoT developer survey : my 2 cents one year later …

As last year, I have decided to write a blog post about my point of view on the IoT developer survey from the Eclipse Foundation (IoT Working Group) with IEEE, Agile IoT and the IoT Council.

From my point of view, the final report gives always interesting insights on where the IoT business is going and about that, Ian Skerrett (Vice President of Marketing at Eclipse Foundation) has already analyzed the results, available here, writing a great blog post.

I want just to add 2 more cents on that …

Industry adoption …

It’s clear that industries are adopting IoT and there is a big increment for industrial automation, smart cities, energy management, building automation, transportation, healthcare and so on. IoT is becoming “real” even if, as we will see in the next paragraphs, it seems that we are still in a prototyping stage. A lot of companies are investing on that but few of them have real solutions running in the field. Finally, from my point of view, it could be great to add more information about countries because I think that there is a big difference on how and where every country is investing for IoT.

The concerns …

Security is always the big concern but, as Ian said, interoperability and connectivity are on a downward trend; I agree with him saying that all the available middleware solutions and the IoT connectivity platforms are solving these problems. The great news is that all of them support different open and standard protocols (MQTT, AMQP but even HTTP) that is the way to go for having interoperability; at same time we are able to connect a lot of different devices, supporting different protocols, so the connectivity problem is addressed as well.

Coming back to security, the survey shows that much more software developers are involved on building IoT solutions even because all the stuff they mostly use are SSL/TLS and data encryption so at software level. From my point of view, some security concerns should be addressed at hardware level (using crypto-chip, TPM and so on) but this is an area where software developers have a lack of knowledge. It’s not a surprise because we know that IoT needs a lot of different knowledge from different people but the survey shows that in some cases not the “right” people are involved on developing IoT solution. Too much web and mobile developers are working on that, too few embedded developer with a real hardware knowledge.

Languages : finally a distinction !

Last year, in my 2 cents, I asked for having a distinction on which side of an IoT solution we consider the most used programming languages. I’m happy to know that Eclipse Foundation got this suggestion so this year survey asked about languages used on constrained devices, gateway and cloud.


The results don’t surprise me : C is the most used language on “real” low constrained devices and all the other languages from Java to Python are mostly used on gateways; JavaScript fits in the cloud mainly with NodeJS. In any case, NodeJS is not a language so my idea is that providing only JavaScript as possible answer was enough even because other than using a server-side framework like NodeJS the other possibility is using JavaScript in “function as a service” platforms (i.e. Lambda from AWS, Azure Functions and so on) that are mostly based on NodeJS. Of course, the most used language in the cloud is Java.

What about OS ?

Linux is the most used OS for both constrained devices and IoT gateways but … here a strange thing comes in my mind. On “real” constrained devices that are based on MCUs (i.e. Cortex-Mx) you can run few specific Linux distros (i.e. uCLinux) and not a full Linux distro so it’s strange that Linux wins on constrained devices but then when the survey shows what distros are used, uCLinux has a very low percentage. My guess is that a lot of software developers don’t know what a constrained device is 🙂

On constrained devices I expect that developers uses “no OS” (programming on bare metal) or a really tiny RTOS but not something closed to Linux.

On gateways I totally agree with Linux but Windows is growing from last year.

Regarding the most used distros, the Raspbian victory shows that we are still in a prototyping stage. I can’t believe that developers are using Raspbian so the related Raspberry Pi hardware in production ! If it’s true … I’m scared about that ! If you know what are the planes, trains, building automation systems which are using something like that, please tell me … I have to avoid them 🙂

Regarding the protocols …

From my point of view, the presence of TCP/IP in the connectivity protocols results is misleading. TCP/IP is a protocol used on top of Ethernet and Wi-Fi that are in the same results and we can’t compare them.

Regarding communication protocols, the current know-how is still leading; this is the reason why HTTP 1.1 is still on the top and HTTP 2.0 is growing. MQTT is there followed by CoAP, which is surprising me considering the necessity to have an HTTP proxy for exporting local traffic outside of a local devices network. AMQP is finding its own way and I think that in the medium/long term it will become a big player on that.

Cloud services

In this area we should have a distinction because the question is pretty general but we know that you can use Amazon AWS or Microsoft Azure for IoT in two ways :

  • as IaaS hosting your own solution or an open source one for IoT (i.e. just using provided virtual machines for running an IoT software stack)
  • as PaaS using the managed IoT platforms (i.e. AWS IoT, Azure IoT Hub, …)

Having Amazon AWS on the top doesn’t surprise me but we could have more details on how it is used by the IoT developers.


The IoT business is growing and its adoption as well but looking at these survey results, most of the companies are still in a prototyping stage and few of them have a real IoT solution in the field.

It means that there is a lot of space for all to be invited to the party ! 😀