Openstack and Cisco

Cisco is investing a lot in Openstack, as other vendors do these days.
Initiatives include being a Gold member of the Openstack Foundation, being in the board of directors, contribute to different projects in Openstack (mainly Neutron, that manages networking, but also Nova and Ironic) with blueprints and code development.

Cisco also uses Openstack in his own data centers, to provide cloud services to the internal IT (our private cloud) and to customers and partners (the Cisco Cloud Services in the Intercloud ecosystem). We also have a managed private cloud offer based on Openstack (formerly named Metacloud).


Based on this experience, a CVD (Cisco Validated Design) has been published to allow customers to deploy the Openstack platform on the Cisco servers and network. The prescriptive documentation guides you to install and configure the hardware and the software in such a way that you get the expected results in terms of scale and security. It's been fully tested and validated in partnership with Red Hat.

Another important point is the offer of the Cisco ACI data model to the open source community. The adoption of such a model in Openstack (the GBP, i.e. the Group Based Policy) is a great satisfaction for us.

Openstack will also be managed by the Stack Designer in Cisco Prime Service Catalog (PSC 11.0), to create PaaS services based on Heat (similarly to what we do now with Stack Designer + UCS Director). Templates to deploy a given Data Center topology will be added as services in the catalog and, based on them, other services could be offered with the deployment of a software stack on top of the Openstack IaaS. The user will be able to order, in a single request, the end to end deployment of a new application.

 

In this post I will tell you about the main topics in the Cisco-Openstack relationship:

1 - Available Plugins for Cisco products (Nexus switches, UCS servers, ACI, CSR, ASR)
2 - GBP: Group Based Policy (the ACI model adopted by the Openstack community)

Available Plugins for Cisco products

Plugins exist for the following projects in Openstack: Neutron, Nova, Ironic.

You can leverage the features of the Cisco products while you maintain the usual operations with Openstack: the integration of the underlying infrastructure is transparent for the user.

 

Networking - Project Neutron

Plugins for all the Nexus switching family      
 - Tenant network creation is based on VLAN or VXLAN
Plugins for ACI      
 - Neutron Networks and Routers are created as usual and the plugin has the role to integrate the API exposed by the Cisco APIC controller

A number of Neutron plugins are available already: Nexus 1000v, 3000, 5000, 6000, 7000 and 9000 Series Switches are supported (see http://www.cisco.com/c/en/us/products/collateral/switches/nexus-3000-series-switches/data_sheet_c78-727737.html).

You can also scale the OpenStack L3 services using the Cisco ASR1K platform (see http://blogs.cisco.com/datacenter/scaling-openstack-l3-using-cisco-asr1k-platform#more-163906) and use the Cloud Services Router (CSR) for Openstack VPN as a Service (see Neutron blueprints web site for Kilo and http://specs.openstack.org/openstack/neutron-specs/specs/kilo/cisco-vpnaas-and-router-integration.html).

Network Service Plug-in Architecture (ML2)

This pluggable architecture has been designed to allow for common API, rapid innovation and vendor differentiation:

Based on the delegation of the real networking service to the underlying infrastructure, the Openstack user does not care what networking devices are used: he only knows what service he needs, and he gets exactly that.

Use the existing Neutron API with APIC and Cisco ACI   

When the Openstack user creates the usual constructs (Networks, Subnets, Routers) via Horizon or the Neutron API, the APIC ML2 plugin intercepts the request and send commands to the APIC API.
Network profiles, made of End Point Groups and Contracts, are created and pushed to the fabric. Virtual networks created in the OVS virtual switch in KVM are matched to the networks in the physical fabric, so that traffic can flow to and from the external world.

Another plugin is the one for the Cisco UCS servers, leveraging the UCS Manager API.
This integration allows you to leverage the single point of management of a UCS domain (up to 160 servers) instead of configuring networking on the single blades or - as in competing server architectures - on the individual switches in the chassis.

An additional advantage offered by UCS servers is the VM-FEX (VM fabric extender) feature: virtual NICs can be offered to the VM directly from the hw, bypassing the virtual switch in the hypervisor thanks to SR-IOV and gaining performances and centralization of the management. 

Next picture shows the automated VLAN and VM-FEX Support offered by the Cisco UCS Manager plugin for OpenStack Neutron:

Bare metal deployment - Project Ironic  

Plugin for UCS Manager to deploy Service Profiles for bare metal workloads on the UCS blades

Ironic is the OpenStack service which provides the capability to provision bare metal servers. The initial version of Ironic pxe_cisco driver adds support to manage power operations of Cisco UCS B/C series servers that are UCSM managed and provides vendor_passthru APIs.
User can control the power operations using pxe_cisco driver. This doesn’t require IPMI protocol to be enabled on the servers as the operations are controlled via Service Profiles.

The vendor_passthru APIs allows the user to enroll the nodes automatically to Ironic DB. Also provides APIs to get the Node specific information like, Inventory, Faults, Location, Firmware Version etc.
Code is available in GitHub @ https://github.com/CiscoUcs/Ironic-UCS

GBP: Group Based Policy

The most exciting news is the adoption of the GBP (Group Based Policy) model and API in Neutron, that derives from the way the Cisco APIC controller manages end point groups and contracts in the ACI architecture. A powerful demonstration of the Cisco thought leadership in networking.

The Group Based Policy (GBP) extension introduces a declarative policy driven framework for networking in OpenStack. The GBP abstractions allow application administrators to express their networking requirements using group and policy abstractions, with the specifics of policy enforcement and implementation left to the underlying policy driver. This facilitates clear separation of concerns between the application and the infrastructure administrator.

Two Options for the OpenStack Neutron API

The Neutron user can now select the preferred option between two choices: the usual building blocks in Neutron (Network, Subnet, Router) and the new - optional - building blocks offered by GBP.

 

In addition to support for the OpenStack Neutron Modular Layer 2 (ML2) interface, Cisco APIC supports integration with OpenStack using Group-Based Policy (GBP). GBP was created by OpenStack developers to offer declarative abstractions for achieving scalable, intent-based infrastructure automation within OpenStack. It supports a plug-in architecture connecting its policy API to a broad range of open source and vendor solutions, including APIC.
This means that other vendors could provide plugins for their infrastructure, to use with the GBP API.
While GBP is a northbound API for Openstack, the plugins are a southbound implementation.

In this case the Neutron plugin for the APIC controller has a easier task: instead of translating from the legacy constructs (Networks, Subnets, Routers) to the corresponding ACI constructs (EPG, Contracts), it will just resend (proxy) identical commands to APIC.

Read more about group-based policy at https://wiki.openstack.org/wiki/GroupBasedPolicy and the Cisco Application Policy Infrastructure Controller Driver for OpenStack Group-Based Policy Data Sheet

In few days, at the Openstack Summit in Vancouver, we'll see all the latest news about the Cisco contribution to Openstack. Don't miss it!

[Added on June 14, 2016]
You can read how easy is to start with Openstack in Why don't you try Openstack (without getting your hands dirty)?

Useful Links:

http://www.cisco.com/c/en/us/solutions/data-center-virtualization/openstack-at-cisco/index.html 
http://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-733126.pdf
http://specs.openstack.org/openstack/neutron-specs/specs/kilo/cisco-vpnaas-and-router-integration.html

GBP
https://www.openstack.org/summit/openstack-paris-summit-2014/session-videos/presentation/group-based-policy-extension-for-networking
http://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/openstack-at-cisco/datasheet-c78-734181.html
https://www.rdoproject.org/Neutron_GBP

The Elastic Cloud project - Porting to UCSD

Porting to a new platform

This post shows how we did the porting of the Elastic Cloud project to a different platform.
The initial implementation was done on Cisco IAC (Intelligent Automation for Cloud) orchestrating Openstack, Cisco ACI (Application Centric Infrastructure) and 3 hypervisors.

Later we decided to implement the same use case (deploy a 3 tier application to 3 different hypervisors, using Openstack and ACI) with Cisco UCS Director, aka UCSD.

The objective was to offer another demonstration of flexibility and openness, targeting IT administrators rather than end users like we did in the first project.
You will find a brief description of UCS Director in the following paragraphs: essentially it is not used to abstract complexity, but to allow IT professionals to do their job faster and error-proof.
UCSD is also a key element in a new Cisco end-to-end architecture for cloud computing, named Cisco ONE Enterprise Cloud suite.

The implementation was supported by the Cisco dCloud team, the organization that provides excellent remote demo capabilities on a number of Cisco technologies. They offered me the lab environment to build the new demo and, in turn, the complete demo will be offered publicly as a self service environment on the dCloud platform.

The dCloud demo environment

Cisco dCloud provides Customers, Partners and Cisco Employees with a way to experience Cisco Solutions. From scripted, repeatable demos to fully customizable labs with complete administrative access, Cisco dCloud can work for you. Just login to dcloud.cisco.com with your Cisco account and you'll find all the available demo:

Cisco UCS Director

UCSD is a great tool for Data Center automation: it manages servers, network, storage and hypervisors, providing you a consistent view on physical and virtual resources in your DC.

Despite the name (that could associate it to Cisco UCS servers only) it integrates with a multi-vendor heterogeneous infrastructure, offering a single dashboard plus the automation engine (with a library containing 1300+ tasks) and the SDK to create your own adapters if needed.

UCSD offers open API so that you can run its workflows from the UCSD catalog or from a 3rd party tool (a portal, a orchestrator, a custom script).

There is a basic workflow editor, that we used to create the custom process integrating Openstack, ACI and all the hypervisors to implement our use case. We don't consider UCSD a full business level orchestrator because it's not meant to integrate also the BSS (Business Support Systems) in your company, but it does the automation of the DC infrastructure including Cisco and 3rd party technologies pretty well.

Implementing the service in UCS Director

Description of the process

The service consists in the deployment of the famous 3 tier application with a single click.
The first 2 tiers of the application (web and application servers and their networks) are deployed on Openstack. The first version of the demo uses KVM as the target hypervisor for both tiers, next version will replace one of the Openstack compute nodes with Hyper-V.
The 3rd tier (the database and its network) is deployed on ESXi.
On every hypervisor, virtual networks are created first. Then virtual machines are created and attached to the proper network.

To connect the virtual networks in their different virtualized environments we used Cisco ACI, creating policies through the API of the controller.
One End Point Group is created for each of the application tiers, Contracts are created to allow the traffic to flow from one tier to next one (and only there).
If you are not familiar with the ACI policy model, you can see my ACI for Dummies post.

All these operations are executed by a single workflow created in the UCSD automation engine.
We just dropped the tasks from the library to the workflow editor, provided input values for each task (from the output of previous tasks) and connected them in the right sequence drawing arrows.
The resulting workflow executes the same sequence of atomic actions that the administrator would do manually in the GUI, one by one.

The implementation was quite easy because we were porting an identical process created in Cisco IAC: the tool to implement the workflow is different, but the sequence and the content of the tasks is the same.

Integration out-of-the-box

Most of the tasks in our process are provided by the UCSD automation library: all the operations on ACI (through its APIC controller) and on ESXi VM and networks (through vCenter).

When you use these tasks, you can immediately see the effect in the target system.
As an example, this is the outcome of creating a Router in Openstack using UCSD: the two networks are connected in the hypervisor and the APIC plugin in Neutron talks immediately to Cisco ACI, creating the corresponding Contract between the two End Point Groups (please check the Router ID in Openstack and the Contract name in APIC).

 

Custom tasks

The integration with Openstack required us to build custom tasks, adding them to the library.
We created 15 new tasks, to call the API exposed by the Openstack subsystems: Neutron (to create the networks) and Nova (to create the VM instances).
The new tasks were written in Javascript, tested with the embedded interpreter, then added to the library.

After that, they were available in the automation library among the tasks provided by the product itself.
This is a very powerful demonstration of the flexibility and ease of use of UCSD.

I should add that the custom integration with Openstack was built for fun, and as a demonstration.
To implement the deployment of the tiers of the application to 3 different hypervisors we could use the native integration that UCSD has with KVM, Hyper-V and ESXi (through their managers).
There's no need to use Openstack as a mediation layer, as we did here.

The workflow editor

Here you can drag 'n drop the task, validate the workflow, run the process to test it and see the executed steps (with their log and all their input and output values).

Amount of effort

The main activities in building this demo are two:
- creating the custom tasks to integrate Openstack
- creating the process to automate the sequence of atomic tasks.

The first activity (skills required: Javascript programming and understanding of the Openstack API) took 1 hour per task: a total of 2 days.
Jose, who created the custom tasks, has also published a generic custom task to execute REST API calls from UCSD: https://github.com/erjosito/stuff/blob/master/UCSD_REST_custom_tasks.wfdx
In addition, he suggests a simple method to understand what REST call corresponds to a Openstack CLI command.
If you use the  --debug option in the Openstack CLI you will see that immediately.

As an example, to boot a new instance:
nova --debug boot --image cirros-0.3.1-x86_64-uec --flavor m1.tiny --nic net-id=f85eb42a-251b-4a75-ba90-723f99dbd00f vm002


The second activity (create the process, test it step by step, expose it in the catalog and run it end to end) took 3 sessions of 2 hours each.
This was made easier by the experience we matured during the implementation of the Elastic Cloud Project. We knew already the atomic actions we needed to perform, their sequence and the input/output parameter for each action.
If we had to build everything from scratch, I would add 2-3 days to understand the use case.

Demo available on dCloud

The demo will be published on the Cisco dCloud site soon for your consumption.
There are also a number of demonstrations available already, focused on UCS Director.
You can learn how UCSD manages the Data Center infrastructure, how it drives the APIC controller in the ACI architecture, and how it is leveraged by Cisco IAC when it uses the REST API exposed by UCSD.

Acknowledgement

A lot of thanks to Simon Richards and Manuel Garcia Sanes from Cisco dCloud, to Russ Whitear from my same team and to Jose Moreno from the Cisco INSBU (Insieme Business Unit).
Great people that focus on Data Center orchestration and many other technologies at Cisco!

You can also find a powerful, yet easy demonstration of how UCSD workflows can be called from a client (a front end portal, another orchestrator...) at Invoking UCS Director Workflows via the Northbound REST API

Cloud Computing as an extension of SOA

When I started explaining my view of Cloud Computing as an extension of SOA (Service Oriented Architecture) someone didn't take it seriously.
I delivered some TOI sessions to increase the awareness on topics that Cisco was approaching in its transformation into a IT company: software architecture, distributed systems, IT service management. I reused some of the concepts and the slides that I created when I was a SOA evangelist.

The feedback was positive and generated a useful discussion, but I also got few comments like: "this is old stuff, cloud is different" and "don't be nostalgic".
After those days, indeed, I've seen many articles comparing Cloud and SOA.

And it is natural: both the architectures (actually cloud is a consumption model more that a architecture) are based on the concept of Service. To be precise, to offer and consume cloud services you need to build a SOA.

It is easy to understand: to begin with, the consumer of a cloud service wants to delegate the build, the ownership and the operations to a third party, that assumes the responsibility for the SLA.
The service is considered a function that someone else provides to you, and you only care the interface to access it (and the quality and the price). You are interested only in the protocol and the user interface - or the API - plus the URL where you get the service.

The actual implementation is not your business. The service (IaaS, PaaS, SaaS) can run on any platform, in any part of the world, fully automated or manual, implemented in any of the hundreds of programming languages. You just don't care, as long as they respect the SLA.

Definitions

The most known definition of cloud computing is from NIST:
 

While SOA was defined, when I was at BEA Systems (one of the SOA pioneers), in this way:

SOA is an architectural approach that enables the creation of loosely coupled, 

interoperable business services that can be easily shared  

within and between enterprises.

A slightly more technical definition is: "Service-Oriented Architecture is an IT strategy that organizes the discrete functions contained in enterprise applications into interoperable, standards-based services that can be combined and reused quickly to meet business needs.

You can find a discussion of the SOA reference architecture (sorry, it's limited to my italian readers...) here. Also IBM has a good definition of SOA here.

 

SOA concepts that apply to Cloud 

There are some concepts that you find in both the models: each one would deserve a dedicated post, or maybe a book. I will try to give some essential detail in this post.

• The concept of Service: Consumer and Provider’s responsibility
• Distributed systems, where remote API are invoked over standard protocols
• Separation of concerns: interface vs implementation
• Interface and Contract
• Reuse and Loose Coupling
• Service Repository and Service Catalog
• Service Lifecycle
• Service Assurance
• Strategy and Governance

Basic detail 

 

Distributed systems

A distributed system is made of components that are deployed separately, in most cases remotely. Each of them provides a lower level functionality that can be used as a building block for the solution of a business need.
To inter-operate, they need connectivity and a well defined framework for sending and receiving data, managing security, transactions consistency, availability and many other non-functional requirements.

To make the development of such a complex system easier, the software industry has separated the concept of interface from the actual implementation.
The interface of a sw component specifies the functions it implements, the parameters it expects and  returns, their format, the conversation style (sync/async) and the security constraints. It is an artifact that can be produced - and deployed - before the actual implementation is ready: you can generate a stub (or mock) component that always returns fake data, but at least it replies to clients allowing the end to end test of the architecture.

So different developers can split the implementation of the system in components that are built in parallel, based on the definition of the interface that they present to each other. The basic integration test can be executed against a stub, to ensure that the conversation works. This also helps rapid prototyping and agile development.

The separation of the interface from the implementation is fundamental when a distributed system is designed.


A Service = Contract + Interface + Implementation 
The set of the above mentioned artifacts identifies a service.

As I stated, the implementation is not relevant for the consumer of the service - but it must exist, otherwise the service cannot be delivered.

The interface is the only visible part of the service, because the consumer will use that one. Depending on the service, it could be a GUI or the API that a client program invokes.

The most important part is the Contract: the agreement (generally defined in a document) defining who has the right to consume the service, the credentials, the price, the SLA, the constraints (e.g. the response time is granted up to 1000 transactions per second), and more.

A given interface could be offered with two distinct contracts, e.g. with different security requirements. Or different price, or different SLA, ect.
If you do that, a new service is generated (a different triple of contract+interface+implementation):

And of course you can differentiate the interface (e.g. sysnchronous vs asynchronous, that is pretty easy if you use a service bus). Also the addition of a new interface will generate a new service:

Reuse and Loose Coupling 

The effort of building a service in a way that makes it reusable is bigger than just implementing a local component in a software project.
Potential consumers of the service will trust it if it is robust enough, it scales, it is secure, etc.
You need to provide information on what the service does, how to use it, how do you support it.
So a business justification is needed for the additional effort to create a reusable service, both for internal usage (SOA) or as a cloud service.

The integration between service consumers and providers should not create tight dependencies, to allow for innovation and maintenance. Coupling refers to the degree of direct knowledge that one element has of another. The separation of the interface from the implementation plays an important role here, because one could change the implementation without affecting the published interface.
In case of major changes, versioning the interface helps.
See also these definitions of loose coupling on Wikipedia and Techtarget.

Service Repository and Service Catalog

I said that you need to provide information on the service and, eventually, market it. If potential consumers don't know that it exists, they will never use it. They also need descriptive info and technical details.
This is true when you build services for the enterprise architecture, even more if you want to sell them in the cloud. 

An important element of the Service Oriented Architecture was the Service Repository. A central point where all the artifacts produced by projects are exposed for reuse, complemented by the Registry offering a link to the service end points.
Now we have the concept of Service Catalog, managing the entire life cycle of a cloud service: from the inception to the decommissioning, passing through cost models and tenants management.
You can find a definition of a service catalog and its usage in this excellent free book: Defining IT Success Through the Service Catalog

 

Service Lifecycle

When a new service is created, you need to design its provisioning process - that could include fully automated or manual steps, including authorizations - its cost model, the management of the resources allocated for a tenant, the assurance of the quality of the service, the billing and end user reporting, the decommissioning and returning the resource to the shared pool.

It is good to have tools to manage all these phases of the life cycle. A choice of CMS (Cloud Management Systems) is offered by Cisco, that have a solution for a ready to run cloud implementation with pre built services (Cisco Intelligent Automation for Cloud, aka IAC) and the just released Cisco ONE Enterprise Cloud suite, a flexible environment where you can create new services with a very little effort, in a bottom-up approach (from the infrastructure to the catalog).
Both the suites use Cisco Prime Service Catalog (PSC) and the front end. PSC is ranked very high by analysts when they examine the features of service catalogs on market.

 

Service Assurance

Monitoring the infrastructure is essential, if you are a service provider. But it is not enough, because you can't immediately correlate the health status of the infrastructure with the quality of the services that consumers perceive (availability, response time, completeness of the result...).
More sophisticated tools are needed to report the services heath score to the Operations team and to the end users, and to allow troubleshooting.
Root cause analysis is the investigation of the ultimate cause for a service failure that could be due to software, servers, network, storage.
Impact analysis is the notification of the list of services impacted by a fault in the infrastructure, that helps the Operations team to restore the services before consumers complain for a violation of the SLA.

Strategy and Governance

IT governance provides the framework and structure that links IT resources and information to enterprise goals and strategies. Furthermore, IT governance institutionalizes best practices for planning, acquiring, implementing, and monitoring IT performance, to ensure that the enterprise's IT assets support its business objectives.

In recent years, IT governance has become integral to the effective governance of the modern enterprise. Businesses are increasingly dependent on IT to support critical business functions and processes; and to successfully gain competitive advantage, businesses need to manage effectively the complex technology that is pervasive throughout the organization, in order to respond quickly and safely to business needs.

In addition, regulatory environments around the world are increasingly mandating stricter enterprise control over information, driven by increasing reports of information system disasters and electronic fraud. The management of IT-related risk is now widely accepted as a key part of enterprise governance.

It follows that an IT governance strategy, and an appropriate organization for implementing the strategy, must be established with the backing of top management, clarifying who owns the enterprise's IT resources, and, in particular, who has ultimate responsibility for their enterprise-wide integration.

I discussed this topic with reference to SOA (only in italian, again... sorry) in SOA è solo tecnologia? and in

6 errori da non fare in un progetto SOA

 

Enterprise Service Bus

The ESB is a core component in the SOA Reference Architecture. It has the role of a mediation layer between the consumers and the providers of any service, managing the match of available interfaces, the security, the quotas and - in general - the enforcement of the Contract.
The ESB is the backbone of a Enterprise Architecture where new projects benefit from reusing already implemented services.

When you think about cloud, the public interface to available services is offered publicly to consumers. Very often, it consists in a set of API to provision and consume the services. A ESB is not strictly required to expose your implementation as a service, but it can certainly help.
Creating multiple interfaces, as long as new contracts are defined for a service, is just a few clicks activity. There are many ESB available as commercial products, next paragraph shows one example but the same capabilities are commonly available on the market and in the open source.

ESB Core Capabilities (courtesy of Mule Soft - http://www.mulesoft.com/platform/soa/mule-esb-open-source-esb):

• Service Mediation
  Separate business logic from protocols and message formats for rapid, nimble development and long-term flexibility.
• Service Orchestration
  Coordinate and arrange multiple services and expose them as a second-generation composite application.
• Service Creation & Hosting
  Expose app functionality as a service and create an efficient standards-based architecture or host existing services in lightweight containers.
• Message Routing
  Direct messages based on content or predetermined rules and filter, aggregate, or re-sequence as required.
• Data Transformation
  Transform data to and from any format across heterogeneous transport protocols and data types or enhance incomplete messages.
• Event Handling
  Deliver synchronous and asynchronous events, transactions, streaming, routing patterns, and a SEDA architecture.

So are SOA and Cloud identical?

Of course not. They have a lot of common concerns, but while SOA was created to address IT and business needs in a single Enterprise context, Cloud is a wider model that offers commercial services across companies.
There's still the private cloud model, where services are offered internally.
Here we have the same self service consumption model, so the automation of the provisioning is critical as well as the quality of the Service Catalog that you offer to consumers.

The most important lesson from SOA that we can reuse in Cloud is that the human factor is sometimes more impactful than the technology.
Change management is one of the key initiatives that help winning the resistance (both in the IT organization, when a new operational model is adopted, and across consumers that are offered a new way of using applications or implementing new projects). 

A proper documentation of the services is key, and the definition of a go-to-market strategy before you start your journey is fundamental: technology should not be adopted because it's smart or because others are doing the same.
It should always be functional to business requirements and be aligned with the corporate strategy.

Links

http://en.wikipedia.org/wiki/Service-oriented_architecture

http://www.alleywatch.com/2013/03/people-as-a-service/
http://csrc.nist.gov/publications/nistpubs/800-145/SP800-145.pdf
http://www-01.ibm.com/software/solutions/soa/what-is-soa.html
http://www.mulesoft.com/platform/soa/mule-esb-open-source-esb

ACI for Simple Minds

Cisco ACI means Application Centric Infrastructure 

Why application designers and developers don't want to speak to network engineers. 

In my previous life I was an enterprise architect and I led design and development of software systems in many projects. When we were in the phase of planning the procurement and the setup of the various environments for the project (dev, test, QA, prod) I was bored by the meetings with the infrastructure guys.
What I needed was a given amount of memory and CPU power, that I could calculate myself, on a single big server or on a number of smaller machines. Then I needed connectivity among the different deployment units in my architecture (a cluster of web servers, a cluster of application servers, a database and some pre-existing systems), and just some services like load balancing.
But those nasty network engineers and the ugly security guys wanted to discuss a long list of requirements and settings: vlans, ip addresses, subnets, firewalls, quality of service, access lists   :-(
I was only interested in application tiers and dependencies, SLA, application performances and compliance and I wanted to discuss that in my language, not in their unfamiliar slang.

How the system engineers see the world: a number of devices with their configuration.

 

How I see the world: a number of servers (or processes) with their role in the application. We can call them End Points.

The communication can be described as a contract.

Provided by some end points, consumed by others. 

And saved as a reusable policy, that could be applied to End Point Groups:

 

 

Eventually, network services like load balancers or firewalls can be added (creating a service graph):

You can easily understand that our meetings were not that easy    ;-)
It was not their fault (and of course it was not... mine): we only saw the world from different angles, or maybe with different glasses.

For the software guys, abstracting the topology of the deployment is essential. For the system guys, devil is in the detail and they need to know exactly what traffic is flowing to engineer the setup accordingly.

Having a set of policies that describe the desired behavior makes the conversation easy: what service is offered by a end point group, what group (or single end point) can consume it, what SLA should be enforced, etc... Contracts could be: access to a web application on http on port 80, access to montoring agents or to log collectors, access to a LDAP server for authentication and so on.
You will see later in the post that ACI allows this conversation.

After long discussions and escalations, the setup of the environment was never as fast as I needed.
It was not the DevOps time yet, but we still tried to roll out many builds of the application for rapid prototyping and quick wins.

Now imagine that you were able to agree on the policy definition.
Having an instant enforcement of those policies on all your network devices without touching them one by one, in a consistent way that prevents human errors and grants compliance by default, and have it done soon would be a miracle... or a magic.

Now we have a network architecture that makes this miracle real: Cisco ACI.
A single software controller (redundant, of course) manages all the network connectivity, security and the network services like load balancers and firewalls.
The network is a hardware fabric, with great performances, scalability, resiliency that I will not discuss here (see the links below for the detail), that extends smoothly into the virtual networks of any vendor or open source solution enforcing the policies for physical servers and VM as end points without any difference.
The controller (named APIC) has a GUI but, most important, a rich set of open API that can be invoked by your scripts, by orchestration tools from Cisco or 3rd parties, by cloud management systems.
You can create the policy from here, and also see the "telemetry" of the network with easy display of the health score of the fabric or individual applications as well.

Use cases for ACI

Fast provisioning

A stateless network like ACI can be provisioned and completely reshaped in seconds by pushing new policies through the controller.
This concept is pretty similar to what the UCS Service Profile made possible in the server industry, introducing the stateless computing.
You can add the complete configuration for a new application to a multitenant shared infrastructure, you can create a new tenant environment, you can create the test environment and the production environment just by cloning the development environment and applying any needed policies to ensure compliance.
Everything is represented as a XML document or a JSON data structure: in any case a small piece of text data that can be saved, versioned and built automatically by a automation script or tool.
Infrastructure as code is one of the pillars of DevOps.

Physical and virtual networking managed the same

When you design End Point Groups and their Contracts, they can be mapped to physical servers (i.e. servers running a single Operating System, like Linux, Unix or Windows servers) or to VM running on any hypervisor.
Traffic from a VM is encapsulated and isolated from other VM's, then the policies are applied to allow it to flow to the destination (physical or virtual).
The spine-leaf architecture of the fabric is extended by a virtual leaf that runs in the hypervisor, under the control of the APIC Controller.

Service Graph

The integration of network services (LB, FW, etc.) from 3rd parties is easy thanks to the Opflex protocol, that allows the extension of the declarative style (vs imperative) of the configuration.
You can add the services to a contract and all the end point that offer and consume that contract will benefit from the insertion without any need for local configuration (e.g. changing the default gateway to the newly inserted firewall).
Many 3rd party vendors added - or will add soon - Opflex agents to their product. The wide ecosystem of ACI becomes richer every day.

Easy deprovisioning

Often, when an existing application is deprovisioned, the network and security configurations created for it are not deleted.
This is due to different reasons: either because it's hard to find them (not all the organizations use a CMDB to track everything) or because the responsible for the operation is afraid of removing firewall rules, ACL, vlans that could potentially be used by a different application, creating a problem as a consequence.

If you have all the policies for a given application defined as attributes of a specific Application Network Profile in APIC, simply removing that ANP will clean all the configurations. You were not applying rules to ports (where other application could be attached) but to end points.

Finally, what advantages can you get from ACI?

Centralized Policy-Defined Automation Management
 • Holistic application-based solution that delivers flexibility and automation for agile IT
 • Automatic fabric deployment and configuration with single point of management
 • Automation of repetitive tasks, reducing configuration errors

Open and Comprehensive End-to-End Security
 • Open APIs, open standards, and open source elements that enable software flexibility for DevOps teams, and firewall and application delivery controller (ADC) ecosystem partner integration
 • Automatic capture of all configuration changes integrated with existing audit and compliance tracking solutions
 • Detailed role-based access control (RBAC) with fine-grained fabric segmentation

Real-Time Visibility and Application Health Score
 • Centralized real-time health monitoring of physical and virtual networks
 • Instant visibility into application performance combined with intelligent placement decisions
 • Faster troubleshooting for day-2 operation

Application Agility
 • Management of application lifecycle from development, to deployment, to decommissioning in minutes
 • Automatic application deployment and faster provisioning based on predefined profiles
 • Continuous and rapid delivery of virtualized and distributed applications

If you liked this post, you may want to read also ACI for (smarter) Simple Minds. You have passed the basic stage now   :-)

Links

Serious product documentation

ACI Marketing page
ACI at a glance
ACI in one page
Application Centric Infrastructure (ACI) Documentation
Learning ACI - Adam's blog

Cartoons (2 min. each)

2015 ACI Video Episode 1: An Impossible Deadline

2015 ACI Video Episode 2: The Needle in the Haystack 

2015 ACI Video Episode 3: Operation Clean Up

The Elastic Cloud project - Methodology

This posts is the continuation of the post The Elastic Cloud Project - Architecture.

Here I will explain how we worked in the project: the sequence of activities that were required and the basic technologies we adopted.

The concepts are mostly explained by using pictures and screen shots, because an image is often worth 1000 words.

If you are interested in more detail, please add a comment or send me a message: I’ll be glad to provide detailed information.

To begin with, we had to:

• map the data model of the products used to understand what objects should be created, for a Tenant, in all the layers of the architecture
• create sequence diagrams to make the interaction clear to all the members of the team - and to the customer
• understand how the API exposed by Openstack Neutron and from Cisco APIC work, how they are invoked and what results they produce
• implement workflows in the CPO orchestrator to call the APIC controller and reuse the existing services in Cisco IAC
• integrate Hyper-V compute nodes in Openstack Nova
• create a new service in the Service Catalog to order the deployment of our 3 tiers application

Some detail about the activities above:

1 - Map the data model of the products used to understand what objects should be created, for a Tenant, in all the layers of the architecture

know that some of you still don’t know Cisco ACI… I promise that I will post a “ACI for dummies” soon.   :-)

  

This picture shows how concepts in Openstack Neutron map to concepts in Cisco ACI:

2 - Create sequence diagrams to make the interaction clear to all the members of the team

3 - Understand how the API exposed by Openstack Neutron and from Cisco APIC work, how they are invoked and what results they produce

This is a call to the Cisco APIC controller, using XML

This is a call to the Openstack Nova API, using JSON:

to do this, we used a REST client to learn the individual behavior and how the parameters need to be passed

a REST call is essentially a http call (GET or POST) where the body contains XML or JSON documents

some http headers are required to specify the content type and to hold security information (like a token for single sign on, that is returned by the authorization call and you need to resend in all the following calls to be recognized.

So we adopted Google Postman, that is a plugin for the Chrome browser (latest version is also released as a standalone application) to practice with the REST Calls then,after we learned how to manage them, we just copied the same content (plus the headers) into the “http call” tasks in the CPO workflow editor.

The XML or JSON variables that we passed are essentially static documents with some placeholders for current values, i.e. the Tenant name, the Network name, etc. were passed according to the user input.

Of course the XML elements tags are described in the APIC product documentation, you don’t have to reverse engineer their meaning   ;-)

Another way to get the XML ready to use is to export it from the APIC user interface: if you select an object that has been created already (either though the GUI or the API), you can export the corresponding XML definition:

This is how we copied the XML content from the test made in Postman and replaced some elements with placeholders for current values (that are variables in the workflow designer):

This is how the variable appear in the workflow instance viewer, after you have executed the process because a user ordered the service:

4 - Implement workflows in the CPO orchestrator to call the APIC controller and reuse the existing services in Cisco IAC

An example of the services that Cisco IAC provides out of the box.

They are also available through the API exposed by the product, so we created a custom workflow that reused some of the services as building block for our use case implementation.

his is the workflow editor, where we created the orchestration flow:

5 - integrate Hyper-V

At the time of this project, a direct support for Microsoft Hyper-V was not available in Openstack Nova.

But a free library was available from Cloudbase, so we decided to install it on our Hyper-V serverso that the virtual data center (VDC) we had created in Cisco IAC thanks to the integration with Openstack could use also Hyper-V resources to provision the VM.

More detail on the integration can be found here: http://www.cloudbase.it/openstack/

In the current Openstack release (Juno), Hyper-V servers are managed directly.

6 - create a new service in the Service Catalog

Conclusion

This project had a complexity that derived from being the among the first teams in the world to try the integration of so many disparate technologies: Cisco software products for Service Catalog and Orchestration, three hypervisors (ESXi, Hyper-V, and KVM), physical networks (Cisco ACI) and virtual networks in all the hypervisors, Openstack.

I didn't tell you, but also load balancers and firewalls were integrated.

Maybe I will post some detail about the Layer 4 - Layer 7 service chaining in the next weeks.

We had to learn the concepts before learning the products. Actually theinvestigation of the API and their integration was the easiest part... and was also fun for my ancient memory of programmer   :-)

Now, with the current release of the products involved in this project, everything would be much easier.

Their features are more complete (actually the integration of the Neutron API in the management of Virtual Data Centers in ACI was fed back to our engineering during this project).

Skills available on the field are deeper and widespread.

I've already implemented the same use case with alternative architectures twice.

Cisco UCS Director was used once, replacing the IAC orchestration and pre-built services.

And, in another variation, the Openstack API were integrated directly instead of reusing the existing services that manage the Openstack VDC in IAC.

Just to have more fun... ;-)

The Elastic Cloud Project - Architecture

This posts is the continuation of The Elastic Cloud Project post.

There is a team at Cisco, called System Development Unit, that creates reference architectures and CVD (Cisco Validated Design).

They work with the product Business Units to define the best way to approach common use cases with the best technology.

But at the time of this project, they hadn’t completed their job yet (some of the products were not even released).

So we had to invent the solution based on our understanding of the end to end architecture and integrate the technologies on the field.

As I explained before, the most important components were:

- servers - Cisco UCS blades and rack mount servers

- network - Cisco ACI fabric, including the APIC software controller

- virtualization - ESXi, Hyper-V, KVM

- cloud and orchestration software - Cisco PSC and CPO, Openstack (PSC and CPO, plus pre-built services, make up Cisco Intelligent Automation - IAC)

IAC can integrate different “element managers” in the datacenter, so that their resources are used to deliver the cloud services (e.g. single VM or Virtual Data Centers - VDC).

Element managers include vmware vCenter and Openstack, so a end user can get a VDC based on one of these platforms.

There is a autometed process in IAC, called CloudSync, that discovers all the resources available in the element managers and allow the admin to select those he wants to use to provision services (resource management and lifecycle management are amongst the features of the product).

The ACI architecture

I will cover it in detail in one of next posts, but essentially ACI (http://www.cisco.com/c/en/us/solutions/data-center-virtualization/application-centric-infrastructure/index.html), that stands for Application Centric Infrastructure, is a holistic architecture with centralized automation and policy-driven application profiles. ACI delivers software flexibility with the scalability of hardware performance. 

Cisco ACI consists of:

• The new Cisco Nexus 9000 Series Switches
• A centralized policy management and Cisco Application Policy Infrastructure Controller (APIC)
• A Cisco Application Virtual Switch (AVS) for the virtual network edge
• Software and hardware innovations
• Integrated physical and virtual infrastructure
• An open ecosystem of network, storage, management, and orchestration vendors
  
  
  

The policies that you create in the software controller (APIC) are enforced by the fabric, including physical and virtual networks.

You describe the behavior your application need from the network, non the configuration you need.

This is easier for the application designer, in the collaboration with network managers, because it can be graphically described by the Application Network Profile.

A profile contains End Point Groups (EPG, representing deployment units of the application: both physical and virtual servers) and Contracts (that define the way EPG can communicate).

A profile can be saved as a XML or JSON document, stored in a repository, participate in the Devops lifecycle, used to clone a environment and managed by any orchestrator.

ACI is integrated with the main virtualization platforms (ESXi, Hyper-V, KVM).

To deploy our 3 tier application on 3 different hypervisors, we had to manage vmware and Openstack separately - but in a single process, because everything should be provisioned with a single click.

Initially we based our custom implementation of the new service on the standard IAC services, using them as building blocks.

So we had not to implement the code to create a network, create a VDC, create a Virtual Server, trigger CloudSync, integrate the virtual network with the hardware fabric.

This sequence of operations was common to the Openstack environment and the vmware environment.

The main workflow was built with two parallel branches, the Openstack branch (creating 2 web servers on one network and 1 application server on anothernetwork) and the vmware branch (doing the same for the database tier).

The problem is that the integration of IAC with Openstack, in the 4.0 release that we used at that time, only deals with Nova - that, in turn, manages both KVM and Hyper-V servers.

No Neutron integration was available out of the box, hence no virtual networks for the Openstack based VDC.

So we built the Neutron integration form scratch (implementing direct REST calls to the Neutron API) to create the networks.

The ACI plugin for Neutron does the rest: it talks to the APIC controller to create the corresponding EPG (End Point Group).

This implementation has been fed back to IAC 4.1 by the Cisco engineering, so in the current release it is available out of the box.

Solution for Openstack

A plugin distributed by Cisco ACI was installed in Openstack Neutron, to allow it to integrate into the APIC controller.

This is transparent to the Openstack user, that goes on working in the usual way: create network, create router, create VM instances.

Instructions are sent by Openstack to APIC, so that the corresponding constructs are deployed in the APIC data model (Application Profiles, End Point Groups, Contracts).

The orchestrator can then use these objects to create a specific application logic, spanning the heterogeneous server farms and allowing networks in KVM to connect to networks in ESXi and Hyper-V.

So the workflow that we built only needed to work with the native API in Openstack.

Logical flow:

— web tier --

create a virtual network for the web tier via Neutron API

     the Neutron plugin for ACI calls - implicitly - the APIC controller and creates a corresponding EPG.

     the Neutron plugin for OVS creates a virtual network in the hypervisor's virtual switch

trigger the CloudSync process, so that the new network is discovered and attached to the VDC

create a VM for the web server and attach it to the network created for the web tier

     this was initially done by reusing the existing IAC service “Provision a new VM"

— application server tier — 

create a virtual network for the app tier via Neutron API

     the Neutron plugin for ACI calls - implicitly - the APIC controller and creates a corresponding EPG.

     the Neutron plugin for OVS creates a virtual network in the hypervisor's virtual switch

trigger the CloudSync process, so that the new network is discovered and attached to the VDC

create a VM for the application server and attach it to the network created for the app tier

     this was initially done by reusing the existing IAC service “Provision a new VM"

— connect the tiers via the controller —  

connect the two EPG with a Contract, that specifies the business rules of the application to be deployed

     this is done via the APIC Controller’s API, creating the Application Profile for the new application in the right Tenant

Solution for vmware

The APIC controller has a direct integration with vmware vCenter, so the integration is slightly different from the Openstack case:

The operations are performed directly against the APIC API and, when you create a EPG there, APIC uses the vCenter integration to create a corresponding virtual network (a Port Group) in the Distributed Virtual Switch.

So we added a branch to the main process to operate on APIC and vCenter, to complete the deployment of the 3 tier application with the database tier. 

Logical flow:

— database server tier — 

call the APIC REST interface, implementing the right sequence (authentication, create Tenant, Bridge Domain, End Point Group, Application Network Profile).

     specifically a EPG for the database tier is created in the APIC data model, and this triggers the creation of a port group in vCenter.

trigger the CloudSync process, so that the new network is discovered and attached to the VDC

create a VM for the database server and attach it to the network created for the app tier

     this was initially done by reusing the existing IAC service “Provision a new VM"

Service Chaining

The communication between End Point Groups can be enriched by adding network services: load balancing, firewalling, etc.

L4-L7 services are managed by APIC by calling external devices, that could be either physical or virtual.

This automation is based on the availability of device packages (set of scripts for the target device), and a protocol (Opflex) has been defined to allow the declarative model supported by ACI being adopted by all 3rd party L4-L7devices. 

Cisco and its partners are working through the IETF and open source community to standardize OpFlex and provide a reference implementation.


In next post, I will describe the methodology we used to integrate the single pieces of the architecture, how we learned to use the API exposed by the target systems (APIC and Openstack) and to insert these calls into the orchestration flow.

Link to next post: The Elastic Cloud Project - Methodology