Industries have resorted to use AI partner services to fuel their AI aspirations and quickly bring their product and services to market. Choosing the right partner is challenging and this blog lists a few pointers that industries can utilize in their decision making process.
Large investments in AI clearly indicate industries have embraced the value of AI. Such a high AI adoption rate has induced a severe lack of talented data scientists, data engineers and machine learning engineers. Moreover, with the availability of alternative options, high paying jobs and numerous benefits, it is clearly an employee’s market.
Market has a plethora of AI consulting companies ready to fill in the role of AI partners with leading industries. Among such companies, on one end are the traditional IT services companies, who have evolved to provide AI services and on the other end are the AI start-up companies who have backgrounds from academia with a research focus striving to deliver the top specialists to industries.
Considering that a company is willing to venture into AI with an AI partner. In this blog I shall enumerate what are the essentials that one can look for before deciding to pick their preferred AI partner.
AI knowledge and experience: AI is evolving fast with new technologies developed by both industries and academia. Use cases in AI also span multiple areas within a single company. Most cases usually fall in following domains: Computer vision, Computer audition, Natural language processing, Interpersonally intelligent machines, routing, and motion and robotics. It is natural to look for AI partners with specialists in the above areas.
It is worth remembering that most AI use cases do not require AI specialists or super specialists and generalists with wide AI experience could well handle the cases.
Also specialising in AI alone does not suffice to successfully bring the case to production. The art of handling industrial AI use cases is not trivial and novice AI specialists and those that are freshly out of University need oversight. Hence companies have to be careful with such AI specialists with only academic experience or little industrial experience.
Domain experience: Many AI techniques are applicable across cases in multiple domains. Hence it is not always necessary to seek such consultants with domain expertise and often it is an overkill with additional expert costs. Additionally, too much domain knowledge can also restrict our thinking in some ways. However, there are exceptions when domain knowledge might be helpful, especially when limited data are available.
A domain agnostic AI consultant can create and deliver AI models in multiple domains in collaboration with company domain experts.
Thus making them available for such projects would be important for the company.
Problem solving approach This is probably the most important attribute when evaluating an AI partner. Company cases can be categorised in one of the following silo’s:
Open sea: Though uncommon, it is possible to see few such scenarios, when the companies are at an early stage of their AI strategy. This is attractive for many AI consultants who have the freedom to carve out an AI strategy and succeeding steps to boost the AI capabilities for their clients. With such freedom comes great responsibility and AI partners for such scenarios must be carefully chosen who have a long standing position within the industry as a trusted partner.
Straits: This is most common when the use case is at least coarsely defined and suitable ML technologies are to be chosen and take the AI use case to production. Such cases often don’t need high grade AI researchers/scientists but any generalist data scientist and engineer with the experience of working in an agile way can be a perfect match.
Stormy seas: This is possibly the hardest case, where the use case is not clearly defined and also no ready solution is available. The use case definition is easy to be defined with data and AI strategists, but research and development of new technologies requires AI specialists/scientists. Hence special emphasis should be focused on checking the presence of such specialists. It is worth noting that AI specialists availability alone does not guarantee that there is a guaranteed conversion to production.
Data security: Data is the fuel for growth for many companies. It is quite natural that companies are extremely careful with safeguarding the data and their use. Thus when choosing an AI partner it is important to look and ask for data security measures that are currently practised with the AI partner candidate organisation. In my experience it is quite common that AI specialists do not have data security training. If the company does not emphasise on ethics and security the data is most likely stored by partners all over the internet, (i.e. personal dropbox and onedrive accounts) including their private laptops.
Data platform skills: AI technologies are usually built on data. It is quite common that companies have multiple databases and do not have a clear data strategy. AI partners with inbuilt experience in data engineering shall go well, else a separate partner would be needed.
Design thinking: Design thinking is rarely considered a priority expertise when it comes to AI partnering and development. However this is probably the hidden gem beyond every successful deployment of AI use case. AI design thinking adopts a human centric approach, where the user is at the centre of the entire development process and her/his wishes are the most important. The adoption of the AI products would significantly increase when the users problems are accounted for, including AI ethics.
Blowed marketing: Usually AI partner marketing slides boast about successful AI projects. Companies must be careful interpreting this number, as often major portions of these projects are just proof of concepts which have not seen the light of day for various reasons. Companies should ask for the percentage of those projects that have entered into production or at least entered a minimum viable product stage.
Above we highlight a few points that one must look for in an AI partner, however what is important over all the above is the market perception of the candidate partner, and as a buyer you believe there is a culture fit, they understand your values, terms of cooperation, and their ability to co-define the value proposition of the AI case. Also AI consultants should stand up for their choices and not shy away from pointing to the infeasibility and lack of technologies/data to achieve desired goals set for AI use cases fearing the collapse of their sales.
Finding the right partner is not that difficult, if you wish to understand Solita’s position on the above pointers and looking for an AI partner don’t hesitate to contact us.
SageMaker Pipelines is a machine learning pipeline creation SDK designed to make deploying machine learning models to production fast and easy. I recently got to use the service in an edge ML project and here are my thoughts about its pros and cons. (For more about the said project refer to Solita data blog series about IIoT and connected factories https://data.solita.fi/factory-floor-and-edge-computing/)
First, there were statistics then came the emperor’s new clothes – machine learning, a rebranding of old methods accompanied with new ones emerged. Fast forward to today and we’re all the time talking about this thing called “AI”, the hype is real, it’s palpable because of products like Siri and Amazon Alexa.
But from a Data Scientist point of view, what does it take to develop such a model? Or even a simpler model, say a binary classifier? The amount of work is quite large, and this is only the tip of the iceberg. How much more work is needed to put that model into the continuous development and delivery cycle?
For a Data Scientist, it can be hard to visualize what kind of systems you need to automate everything your model needs to perform its task. Data ETL, feature engineering, model training, inference, hyperparameter optimization, performance monitoring etc. Sounds like a lot to automate?
Building an MLOps infrastructure is one thing but learning to use it fluently is also a task of its own. For a Data Scientist at the beginning of his/her career, it could seem too much to learn how to use cloud infrastructure as well as learn how to develop Python code that is “production” ready. A Jupyter notebook outputting predictions to a CSV file simply isn’t enough at this stage of the machine learning revolution.
A Jupyter notebook outputting predictions to a CSV file simply isn’t enough at this stage of the machine learning revolution.
Usually, companies that have a long track record of Data Science projects have a few DevOps, Data Engineer/Machine Learning Engineer roles working closely with their Data Scientists teams to distribute the different tasks of production machine learning deployment. Maybe they even have built the tooling and the infrastructure needed to deploy models into production more easily. But there are still quite a few Data Science teams and data-driven companies figuring out how to do this MLOps thing.
Why should you try SageMaker Pipelines?
AWS is the biggest cloud provider ATM so it has all the tooling imaginable that you’d need to build a system like this. They are also heavily invested in Data Science with their SageMaker product and new features are popping up constantly. The problem so far has been that there are perhaps too many different ways of building a system like this.
AWS tries to tackle some of the problems with the technical debt involving production machine learning with their SageMaker Pipelines product. I’ve recently been involved in project building and deploying an MLOps pipeline for edge devices using SageMaker Pipelines and I’ll try to provide some insight on why it is good and what is lacking compared to a completely custom-built MLOps pipeline.
The SageMaker Pipelines approach is an ambitious one. What if, Data Scientists, instead of having to learn to use this complex cloud infrastructure, you could deploy to production just by learning how to use a single Python SDK (https://github.com/aws/sagemaker-python-sdk)? You don’t even need the AWS cloud to get started, it also runs locally (to a point).
SageMaker Pipelines aims at making MLOps easy for Data Scientists. You can define your whole MLOps pipeline in f.ex. A Jupyter Notebook and automate the whole process. There are a lot of prebuilt containers for data engineering, model training and model monitoring that have been custom-built for AWS. If these are not enough you can use your containers enabling you to do anything that is not supported out of the box. There are also a couple of very niche features like out-of-network training where your model will be trained in an instance that has no access to the internet mitigating the risk of somebody from the outside trying to influence your model training with f.ex. Altered training data.
You can version your models via the model registry. If you have multiple different use cases for the same model architectures with differences being in the datasets used for training it’s easy to select the suitable version from SageMaker UI or the python SDK and refactor the pipeline to suit your needs. With this approach, the aim is that each MLOps pipeline has a lot of components that are reusable in the next project. This enables faster development cycles and the time to production is reduced.
SageMaker Pipelines logs every step of the workflow from training instance sizes to model hyperparameters automatically. You can seamlessly deploy your model to the SageMaker Endpoint (a separate service) and after deployment, you can also automatically monitor your model for concept drifts in the data or f.ex. latencies in your API. You can even deploy multiple versions of your models and do A/B testing to select which one is proving to be the best.
And if you want to deploy your model to the edge, be it a fleet of RaspberryPi4s or something else, SageMaker provides tooling for that also and it seamlessly integrates with Pipelines.
You can recompile your models for a specific device type using SageMaker Neo Compilation jobs (basically if you’re deploying to an ARM etc. device you need to do certain conversions for everything to work as it should) and deploy to your fleet using SageMaker fleet management.
Considerations before choosing SageMaker Pipelines
By combining all of these features to a single service usable through SDK and UI, Amazon has managed to automate a lot of the CI/CD work needed for deploying machine learning models into production at scale with agile project development methodologies. You can also leverage all of the other SageMaker products f.ex. Feature Store or Forekaster if you happen to need them. If you’re already invested in using AWS you should give this a try.
Be it a great product to get started with machine learning pipelines it isn’t without its flaws. It is quite capable for batch learning settings but there is no support as of yet for streaming/online learning tasks.
And for the so-called Citizen Data Scientist, this is not the right product since you need to be somewhat fluent in Python. Citizen Data Scientists are better off with BI products like Tableau or Qlik (which use SageMaker Autopilot as their backend for ML) or perhaps with products like DataRobot.
And in a time where software products are high availability and high usage the SageMaker EndPoints model API deployment scenario where you have to pre-decide the number of machines serving your model isn’t quite enough.
In e-commerce applications, you could run into situations where your API is receiving so much traffic that it can’t handle all the requests because you didn’t select a big enough cluster to serve the model with. The only way to increase the cluster size in SageMaker Pipelines is to redeploy a new revision within a bigger cluster. It is pretty much a no brainer to use a Kubernetes cluster with horizontal scaling if you want to be able to serve your model as the traffic to the API keeps increasing.
Overall it is a very nicely packaged product with a lot of good features. The problem with MLOps in AWS has been that there are too many ways of doing the same thing and SageMaker Pipelines is an effort for trying to streamline and package all those different methodologies together for machine learning pipeline creation.
MLOps refers to the concept of automating the lifecycle of machine learning models from data preparation and model building to production deployment and maintenance. MLOps is not only some machine learning platform or technology, but instead it requires an entire change in the mindset of developing machine learning models towards best practises of software development. In this blog post we introduce this concept and its benefits for anyone having or planning to have machine learning models running in production.
Operationalizing data platforms, DataOps, has been among the hottest topics during the past few years. Recently, also MLOps has become one of the hottest topics in the field of data science and machine learning. Building operational data platforms has made data available for analytics purposes and enabled development of machine learning models in a completely new scale. While development of machine learning models has expanded, the processes of maintaining and managing the models have not followed in the same pace. This is where the concept of MLOps becomes relevant.
What is MLOps?
Machine learning operations, or MLOps, is a similar concept as DevOps (or DataOps), but specifically tailored to needs of data science and more specifically machine learning. DevOps was introduced to software development over a decade ago. DevOps practices aim to improve application delivery by combining the entire life cycle of the application – development, testing and delivery – to one process, instead of having a separate development team handing over the developed solution for the operations team to deploy. The definite benefits of DevOps are shorter development cycles, increased deployment velocity, and dependable releases.
Similarly as DevOps aims to improve application delivery, MLOps aims to productionalize machine learning models in a simple and automated way.
As for any software service running in production, automating the build and deployment of ML models is equally important. Additionally, machine learning models benefit from versioning and monitoring, and the ability to retrain and deploy new versions of the model, not only to be more reliable when data is updated but also from the transparency and AI ethics perspective.
Why do you need MLOps?
Data scientists’ work is research and development, and requires essentially skills from statistics and mathematics, as well as programming. It is iterative work of building and training to generate various models. Many teams have data scientists who can build state-of-the-art models, but their process for building and deploying those models can be entirely manual. It might happen locally, on a personal laptop with copies of data and the end product might be a csv file or powerpoint slides. These types of experiments don’t usually create much business value if they never go live to production. And that’s where data scientists in many cases struggle the most, since engineering and operations skills are not often data scientists’ core competences.
In the best case scenario in this type of development the model ends up in production by a data scientist handing over the trained model artifacts to the ops team to deploy, whereas the ops team might lack knowledge on how to best integrate machine learning models into their existing systems. After deployment, the model’s predictions and actions might not be tracked, and model performance degradation and other model behavioral drifts can not be detected. In the best case scenario your data scientist monitors model performance manually and manually retrains the model with new data, with always a manual handover again in deployment.
The described process might work for a short time when you only have a few models and a few data scientists, but it is not scalable in the long term. The disconnection between development and operations is what DevOps originally was developed to solve, and the lack of monitoring and re-deployment is where MLOps comes in.
How can MLOps help?
Instead of going back-and-forth between the data scientists and operations team, by integrating MLOps into the development process one could enable quicker cycles of deployment and optimization of algorithms, without always requiring a huge effort when adding new algorithms to production or updating existing ones.
MLOps can be divided into multiple practices: automated infrastructure building, versioning important parts of data science experiments and models, deployments (packaging, continuous integration and continuous delivery), security and monitoring.
In software development projects it is typical that source code, its configurations and also infrastructure code are versioned. Tracking and controlling changes to the code enables roll-backs to previous versions in case of failures and helps developers to understand the evolution of the solution. In data science projects source code and infrastructure are important to version as well, but in addition to them, there are other parts that need to be versioned, too.
Typically a data scientist runs training jobs multiple times with different setups. For example hyperparameters and used features may vary between different runs and they affect the accuracy of the model. If the information about training data, hyperparameters, model itself and model accuracy with different combinations are not saved anywhere it might be hard to compare the models and choose the best one to deploy to production.
Templates and shared libraries
Data scientists might lack knowledge on infrastructure development or networking, but if there is a ready template and framework, they only need to adapt the steps of a process. Templating and using shared libraries frees time from data scientists so they can focus on their core expertise.
Existing templates and shared libraries that abstract underlying infrastructure, platforms and databases, will speed up building new machine learning models but will also help in on-boarding any new data scientists.
Project templates can automate the creation of infrastructure that is needed for running the preprocessing or training code. When for example building infrastructure is automated with Infrastructure as a code, it is easier to build different environments and be sure they’re similar. This usually means also infrastructure security practices are automated and they don’t vary from project to project.
Templates can also have scripts for packaging and deploying code. When the libraries used are mostly the same in different projects, those scripts very rarely need to be changed and data scientists don’t have to write them separately for every project.
Shared libraries mean less duplicate code and smaller chance of bugs in repeating tasks. They can also hide details about the database and platform from data scientists, when they can use ready made functions for, for instance, reading from and writing to database or saving the model. Versioning can be written into shared libraries and functions as well, which means it’s not up to the data scientist to remember which things need to be versioned.
When deploying either a more traditional software solution or ML solution, the steps in the process are highly repetitive, but also error-prone. An automated deployment pipeline in CI/CD service can take care of packaging the code, running automated tests and deployment of the package to a selected environment. This will not only reduce the risk of errors in deployment but also free time from the deployment tasks to actual development work.
Tests are needed in deployment of machine learning models as in any software, including typical unit and integration tests of the system. In addition to those, you need to validate data and the model, and evaluate the quality of the trained model. Adding the necessary validation creates a bit more complexity and requires automation of steps that are manually done before deployment by data scientists to train and validate new models. You might need to deploy a multi-step pipeline to automatically retrain and deploy models, depending on your solution.
After the model is deployed to production some people might think it remains functional and decays like any traditional software system. In fact, machine learning models can decay in more ways than traditional software systems. In addition to monitoring the performance of the system, the performance of models themselves needs to be monitored as well. Because machine learning models make assumptions of real-world based on the data used for training the models, when the surrounding world changes, accuracy of the model may decrease. This is especially true for the models that try to model human behavior. Decreasing model accuracy means that the model needs to be retrained to reflect the surrounding world better and with monitoring the retraining is not done too seldom or often. By tracking summary statistics of your data and monitoring the performance of your model, you can send notifications or roll back when values deviate from the expectations made in the time of last model training.
Bringing MLOps thinking to the machine learning model development enables you to actually get your models to production if you are not there yet, makes your deployment cycles faster and more reliable, reduces manual effort and errors, and frees time from your data scientists from tasks that are not their core competences to actual model development work. Cloud providers (such as AWS, Azure or GCP) are especially good places to start implementing MLOps in small steps, with ready made software components you can use. Moreover, all the CPU / GPU that is needed for model training with pay as you go model.
If the maturity of your AI journey is still in early phase (PoCs don’t need heavy processes like this), robust development framework and pipeline infra might not be the highest priority. However, any effort invested in automating the development process from the early phase will pay back later and reduce the machine learning technical debt in the long run. Start small and change the way you develop ML models towards MLOps by at least moving the development work on top of version control, and automating the steps for retraining and deployment.
DevOps was born as a reaction to systematic organization needed around rapidly expanding software development, and now the same problems are faced in the field of machine learning. Take the needed steps towards MLOps, like done successfully with DevOps before.
The linked code repository contains a minimal setup to automatize infrastructure and code deployment simultaneously from Azure DevOps Git Repositories to Databricks.
Import the repo into a fresh Azure DevOps Project,
get a secret access token from your Databricks Workspace,
paste the token and the Databricks URL into a Azure DevOps Library’s variable group named “databricks_cli”,
Create and run two pipelines referencing the YAML in the repo’s pipelines/ directory.
Any Databricks compatible (Python, Scala, R) code pushed to the remote repository’s workspace/ directory will be copied to the Databricks workspace with an interactive cluster waiting to execute it.
Azure DevOps and Databricks have one thing in common – providing industry standard technology and offering them as an intuitive, managed platform:
Databricks for running Apache Spark
DevOps for Git repos and build pipelines
Both platforms have much more to offer then what is used in this minimal integration example. DevOps offers wiki, bug-, task- and issue tracking, canban, scrum and workflow functionality among others.
Databricks is a fully managed and optimized Apache Spark PaaS. It can natively execute Scala, Python, PySpark, R, SparkR, SQL and Bash code; some cluster types have Tensorflow installed and configured (inclusive GPU drivers). Integration of the H2O machine learning platform is quite straight forward. In essence Databricks is a highly performant general purpose data science and engineering platform which tackles virtually any challenge in the Big Data universe.
Both have free tiers and a pay-as-you-go pricing model.
Databricks provides infrastructure as code. A few lines of JSON consistently deploy an optimized Apache Spark runtime.
After several projects and the increasing need to build and prototype in a managed and reproducible way the DevOps-Databricks combination became very appreciated: It enables quick and responsive interactive runtimes and provides best industry practice for software development and data engineering. Deployment into (scheduled), performant, resilient production environments is possible without changes to the platform and without any need for refactoring.
The core of the integration uses Databricks infrastructure-as-code (IaC) capability together with DevOps pipelines functionality to deploy any kind of code.
Azure pipelines deploy both the infrastructure code and the notebook code from the repository to the Databricks workspace. This enables version control of both the runtime and the code in one compact, responsive repository.
All pieces of the integration are hosted in a single, compact repository which make all parts of a data and modeling pipeline fully reproducible.
Log into Azure DevOps and Databricks Workspace. There are free tiers for both of them. Setup details are explained extensively in the canonical quick start sections of either service:
For the integration Databricks can be hosted in either the Azure or AWS cloud.
1. Import the Repository
To use this demo as a starting point for a new project, prepare a Azure DevOps project:
create a new project (with an empty repository by default)
select the repository tab and choose “Import a repository”
paste the URL of this demo into the Clone URL field: https://dev.azure.com/reinhardseifert/DatabricksDevOps/_git/DatabricksDevOps
wait for the import to complete
clone the newly imported repository to your local computer to start deploying your own code into the workspace directory
Then create two Azure pipelines which create the runtime and sync any code updates into it (see below).
2. Create Databricks Secret Token
Log into the Databricks Workspace and under User settings (icon in the top right corner) and select “Generate New Token”. Choose a descriptive name (“DevOps Build Agent Key”) and copy the token to a notebook or clipboard. The token is displayed just once – directly after creation; you can create as many tokens as you wish.
3. Add the token to the Azure DevOps Library
The Databricks Secret Token has to be added to a Variable Group named “databricks_cli”. Variable groups are created under Pipelines > Library. Note that the name of the variable group is referenced in both pipeline definitions (/pipelines/build-cluster.yml and /pipelines/build-workspace.yml). Two variables have to be defined: 1. databricks_host and 2. databricks_token
The variable names are referenced in the .yml file – changing them in the DevOps library requires also changing them correspondingly in the .yml files. When clicking the lock icon after defining the variable it is treated as a secret and not visible after that action in the DevOps project. Neither in the Library nor in the Build servers (even when accidentially echo-ing them. But of course writing them to the Databricks environment would potentially expose them. This is a security concern when collaborating with non-trusted parties on a Project.
Generally the Azure DevOps portal offers as minimal functionality a git repository to maintain code and pipelines to deploy the code from the repository into runtimes.
the JSON specification of the Spark-cluster which will run the code,
shell build scripts which are executed in the pipeline/ build server,
the YAML configuration which define the pipelines.
The complete CI/CD pipeline is contained in a single Git repository in a very compact fashion. Following Databricks’ terminology the Python code (1) is located in the workspace/ directory. The runtime specification .json (2), build scripts .sh (3) and the pipeline configuration .yml (4) are located in the pipelines/ directory according to the Azure DevOps paradigm.
The Pipelines menu provides the following functionality:
Pipelines (aka build pipelines),
Environments (needed to group Azure resources – not used here),
Releases (aka release pipelines – not used here)
Library (containing the variable groups)
The build pipelines exclusively used in this demo project are managed under the “Pipelines > Pipelines” menu tab – not really intuitive.
Azure Build Pipelines
The pipeline’s build agents are configured via YAML files (e.g. build-cluster.yml). In this case they install the Databricks CLI on the build machine and then execute CLI commands to create runtimes and move code notebooks to the runtime. The Databricks cluster is configured by a single JSON file (see config.cluster.json).
This minimal integration requires creation of two pipelines:
cluster creation – referencing pipelines/build-cluster.yml and
select the imported repository from the drop-down menu
select Existing Azure Pipeline YAML file
select the YAML file from the drop-down menu
Run the pipeline for the first time – or just save it and run it later.
At this point the Databricks secret access token mentioned in the prerequisite paragraph need to be present in a “databricks_cli” variable group. Otherwise the pipeline run will fail and warn; in this case just create the token (in Databricks) and the variable group (in DevOps) and re-run the pipeline.
After creating the pipelines and saving them (or running them initially), the default pipeline names reference the source repository name which triggers them. For easier monitoring the pipelines should be renamed according to their function, like “create-cluster” and “sync-workspace” in this case.
This concludes the integration of analytic code from an Azure DevOps repository into a hosted Databricks runtime.
Any change to the config.cluster.json deletes the existing cluster and creates a new one according to the specifications in the JSON file.
Any change to workspace/ will copy the notebook file(s) (R, Python, Scala) to the Databricks workspace for execution on the cluster.
The Databricks workspace in this example was hosted on Azure. Only minor changes are required to use an AWS hosted workspace. On all cloud platforms the host URL and security token is specific for the chosen instance and region. The cloud specific parameter is the node_type_id in the cluster configuration .json file.
Using this skeleton repo as a starting point, it is immediately possible to run interactive workloads on a performant Apacke Spark cloud cluster – instead of “cooking” the local laptop with analytic code – transparently maintained on a professional DevOps platform.
Following, a detailed walk-through of the .yml pipeline configurations, .sh build scripts and .json configuration files.
In general, the YAML instructs the build server to 1. start up when a certain file is changed (trigger), 2. copy the contents of the repository to the build server and 3. execute a selection of shell scripts (tasks) from the repository
Pipeline: Create cluster
This is a detailed walk through for the build-cluster.yml pipeline. The .yml files have a hierachical structure and the full hierarchy of the DevOps build pipeline is included although stages could be omitted.
The first section of the pipeline YAML specifies the trigger. Any changes to the specified branch of the linked repo will automatically run of the Build Agent.
Without the paths: section, any change to the master branch will run the pipeline. The cluster is rebuild when the configuration changes or the selection of installed Python- or R-libraries changes.
The stage can be omitted (for a single stage pipeline) and the pool, variables and jobs directly defined. Then the stage would be implicit. It is possible to add testing steps to the pipeline and build fully automated CI/CD pipelines accross environments within on .yml file.
Selects the type of virtual machine to start when the trigger files are changed. At the time of writing ubuntu_latest will start a Ubuntu 18.04 LTS image.
This section references the variable group created in the Prerequisite section. The secret token is transfered to the build server and authorizes the API calls from the server to the Databricks workspace.
Jobs, Steps and Tasks
A job is a sequence of steps which are executed on the build server (pool). In this pipeline only task steps are used (see the docs for all step operations).
The first step is selecting the Python version for all following Python command on the build server; the Databricks CLI is written in Python and installed via Pip in the following task.
Task: Install and configure the Databricks CLI
- task: ShellScript@2
args: "\$(databricks_host) \$(databricks\_token)"
displayName: "Install and configure the Databricks CLI"
Note that the path is relative to the root of the repo. The secret access token and host URL from the DevOps library are copied into environment variables which can be passed to the script in the args section.
The shell script executes the installation of the Databricks CLI and writes the neccessary CLI configuration on the build server.
Task: “Delete previous cluster version (if existing)”
This task will remove any cluster with the name provided in the args: section. This allows for updating the cluster when the configuration file is changed. When no such cluster is present the script will fail. Usually the pipeline will break at this point but here continueOnError is true, so the pipeline will continue when creating a cluster for the first time.
-task: ShellScript@2inputs:scriptPath: pipelines/databricks-cluster-delete.shargs:"HelloCluster"continueOnError:"true"displayName:"Delete previous cluster version (if existing)"
The shell script called by this task is a wrapper around the Databricks CLI. First it queries for the cluster-id of any cluster with the name passed.
CLUSTER_ID=$(databricks clusters list --output json |jq -r --arg N "$CLUSTER_NAME"'.clusters | select(.cluster_name == $N) | .cluster_id')
It is possible to create multiple clusters with the same name. In case there are multiple all of them are deleted.
forID in $CLUSTER_IDdoecho"Deleting $ID"databricks clusters permanent-delete --cluster-id $IDdone
Task: Create new cluster
-task: ShellScript@2inputs:scriptPath: pipelines/databricks-cluster-create.shargs:"HelloCluster"displayName:"Create new cluster"
The build script reads the config.cluster.json and adds the cluster name passed from the pipeline .yml
Now the configuration .json file can be passed to the Databricks CLI. The complete Apache Spark infrastructure is configured in the json. CLUSTER_NAME will be replaced with the name passed from the .yml.
Updating the runtime to another version requires only modifying the spark_version parameter with any supported runtime.
A Spark cluster consists of one driver node and a number of worker nodes and can be scaled horizontally by adding nodes (num_workers) or vertically by choosing larger node types. The node types are cloud provider specific. The Standard_DS3_v2 node type id references the minimal Azure node.
The autotermination feature shuts the cluster down when not in use. Costs are billed per second up time per processing unit.
Any reconfigurations triggers the pipeline and rebuilds the cluster.
The cluster create call returns the cluster-id of the newly created instance. Since the last step of this pipeline installs additional Python and R libraries (via Pip and CRAN respectively) it is necessary to wait for the cluster to be in pending state.
STATE=$(databricks clusters list --output json |jq -r --arg I "$CLUSTER_ID"'.clusters | select(.cluster_id == $I) | .state')echo"Wait for cluster to be PENDING"while [["$STATE"!="PENDING" ]]doSTATE=$(databricks clusters list --output json |jq -r --arg I "$CLUSTER_ID"'.clusters | select(.cluster_name == $I) | .state')done
Task: Install Python and R dependencies on the cluster
The final step is to add additional Python and R packages to the cluster. There are many ways to install packges in Databricks. This is just one way to do it.
-task: ShellScript@2inputs:scriptPath: pipelines/databricks-library-install.shargs:"HelloCluster"displayName:"Install Python and R dependencies"
Again the shell script wraps the Databricks CLI, here the library install command. The cluster name (“DemoCluster” in this example) has to be passed again.
All CLI calls to Databricks need the cluster-id to delete, create and manupulate instances. So first fetch it with a cluster list call:
CLUSTER_ID=$(databricks clusters list --output json |jq -r --arg N "$CLUSTER_NAME"'.clusters | select(.cluster_name == $N) | .cluster_id')
Then install the packages – one call to library install per package:
For additional Python or R package add a line in this build script – this will trigger the pipeline and the cluster is rebuild.
Pipeline: Import workspace
This is a detailed walk through for the build-workspace.yml pipeline. The first part of the pipeline is identical to the build-cluster.yml pipeline. The trigger include differs, since this pipeline is triggered by code pushes to the workspace/ directory. The choice of the build server (pool), the variable reference to the databricks_cli variable group for the Databricks access tokens and the Python version task are identical, also installing and configuring the Databricks CLI with the same build script as above.
The only build task is importing all files in the workspace/ directory to the Databricks Workspace. The args passes a sub-directory name for the /Shared/ folder in Databricks ( /Shared/HelloWorkspace/ in the example).
-task: ShellScript@2inputs:scriptPath: pipelines/databricks-workspace-import.shargs:"HelloWorkspace"displayName:"Import updated notebooks to workspace to dev"
The specified directory is first deleted. When the directory does not exist, the CLI prints and error in JSON format, but does not break the pipeline. The args: parameter is passed to the $SUBDIR variable in the build script.
Machine learning continues to grow on AWS and they are putting serious effort on paving the way for customers’ machine learning development journey on AWS cloud. The Andy Jassy keynote in AWS Re:Invent was a fiesta for data scientists with the newly launched Amazon SageMaker features, including Experiments, Debugger, Model Monitor, AutoPilot and Studio.
AWS really aims to make the whole development life cycle of machine learning models as simple as possible for data scientists. With the newly launched features, they are addressing common, effort demanding problems: monitoring your data validity from your model’s perspective and monitoring your model performance (Model Monitor), experimenting multiple machine learning approaches in parallel for your problem (Experiments), enable cost efficiency of heavy model training with automatic rules (Debugger) and following these processes in a visual interface (Studio). These processes can even be orchestrated for you with AutoPilot, that unlike many services is not a black box machine learning solution but provides all the generated code for you. Announced features also included a SSO integrated login to SageMaker Studio and SageMaker Notebooks, a possibility to share notebooks with one click to other data scientists including the needed runtime dependencies and libraries (preview).
Compare and try out different models with SageMaker Experiments
Building a model is an iterative process of trials with different hyperparameters and how they affect the performance of the model. SageMaker Experiments aim to simplify this process. With Experiments, one can create trial runs with different parameters and compare those. It provides information about the hyperparameters and performance for each trial run, regardless of whether a data scientist has run training multiple times, has used automated hyperparameter tuning or has used AutoPilot. It is especially helpful in the case of automating some steps or the whole process, because the amount of training jobs run is typically much higher than with traditional approach.
Experiments makes it easy to compare trials, see what kind of hyperparameters was used and monitor the performance of the models, without having to set up the versioning manually. It makes it easy to choose and deploy the best model to production, but you can also always come back and look at the artifacts of your model when facing problems in production. It also provides more transparency for example to automated hyperparameter tuning and also for new SageMaker AutoPilot. Additionally, SageMaker Experiments has Experiments SDK so it is possible call the API with Python to get the best model programmatically and deploy endpoint for it.
Track issues in model training with SageMaker Debugger
During the training process of your model, many issues may occur that might prevent your model from correctly finishing or learning patterns. You might have, for example, initialized parameters inappropriately or used un efficient hyperparameters during the training process. SageMaker Debugger aims to help tracking issues related to your model training (unlike the name indicates, SageMaker Debugger does not debug your code semantics).
When you enable debugger in your training job, it starts to save the internal model state into S3 bucket during the training process. A state consists of for example weights for neural network, accuracies and losses, output of each layer and optimization parameters. These debug outputs will be analyzed against a collection of rules while the training job is executed. When you enable Debugger while running your training job in SageMaker, will start two jobs: a training job, and a debug processing job (powered by Amazon SageMaker Processing Jobs), which will run in parallel and analyze state data to check if the rule conditions are met. If you have, for example, an expensive and time consuming training job, you can set up a debugger rule and configure a CloudWatch alarm to it that kills the job once your rules trigger, e.g. loss has converged enough.
For now, the debugging framework of saving internal model states supports only TensorFlow, Keras, Apache MXNet, PyTorch and XGBoost. You can also configure your own rules that analyse model states during the training, or some preconfigured ones such as loss not changing or exploding/vanishing gradients. You can use the debug feature visually through the SageMaker Studio or alternatively through SDK and configure everything to it yourself.
Keep your model up-to-date with SageMaker Model Monitor
Drifts in data might have big impact on your model performance in production, if your training data and validation data start to have different statistical properties. Detecting those drifts requires efforts, like setting up jobs that calculate statistical properties of your data and also updating those, so that your model does not get outdated. SageMaker Model Monitor aims to solve this problem by tracking the statistics of incoming data and aims to ensure that machine learning models age well.
The Model Monitor forms a baseline from the training data used for creating a model. Baseline information includes statistics of the data and basic information like name and datatype of features in data. Baseline is formed automatically, but automatically generated baseline can be changed if needed. Model Monitor then continuously collects input data from deployed endpoint and puts it into a S3 bucket. Data scientists can then create own rules or use ready-made validations for the data and schedule validation jobs. They can also configure alarms if there are deviations from the baseline. These alarms and validations can indicate that the model deployed is actually outdated and should be re-trained.
SageMaker Model Monitor makes monitoring the model quality very easy but at the same time data scientists have the control and they can customize the rules, scheduling and alarms. The monitoring is attached to an endpoint deployed with SageMaker, so if inference is implemented in some other way, Model Monitor cannot be used. SageMaker endpoints are always on, so they can be expensive solution for cases when predictions are not needed continuously.
Start from scratch with SageMaker AutoPilot
SageMaker AutoPilot is an autoML solution for SageMaker. SageMaker has had automatic hyperparameter tuning already earlier, but in addition to that, AutoPilot takes care of preprocessing data and selecting appropriate algorithm for the problem. This saves a lot of time of preprocessing the data and enables building models even if you’re not sure which algorithm to use. AutoPilot supports linear learner, factorization machines, KNN and XGBboost at first, but other algorithms will be added later.
Running an AutoPilot job is as easy as just specifying a csv-file and response variable present in the file. AWS considers that models trained by SageMaker AutoPilot are white box models instead of black box, because it provides generated source code for training the model and with Experiments it is easy to view the trials AutoPilot has run.
SageMaker AutoPilot automates machine learning model development completely. It is yet to be seen if it improves the models, but it is a good sign that it provides information about the process. Unfortunately, the description of the process can only be viewed in SageMaker Studio (only available in Ohio at the moment). Supported algorithms are currently quite limited as well, so the AutoPilot might not provide the best performance possible for some problems. In practice running AutoPilot jobs takes a long time, so the costs of using AutoPilot might be quite high. That time is of course saved from data scientist’s working time. One possibility is, for example, when approaching a completely new data set and problem, one might start by launching AutoPilot and get a few models and all the codes as template. That could serve as a kick start to iterating your problem by starting from tuning the generated code and continuing development from there, saving time from initial setup.
SageMaker Studio – IDE for data science development
The launched SageMaker Studio (available in Ohio) is a fully integrated development environment (IDE) for ML, built on top of Jupyter lab. It pulls together the ML workflow steps in a visual interface, with it’s goal being to simplify the iterative nature of ML development. In Studio one can move between steps, compare results and adjust inputs and parameters. It also simplifies the comparison of models and runs side by side in one visual interface.
Studio seems to nicely tie the newly launched features (Experiments, Debugger, Model Monitor and Autopilot) into a single web page user interface. While these new features are all usable through SDKs, using them through the visual interface will be more insightful for a data scientist.
These new features enable more organized development of machine learning models, moving from notebooks to controlled monitoring and deployment and transparent workflows. Of course several actions enabled by these features could be implemented elsewhere (e.g. training job debugging, or data quality control with some scheduled smoke tests), but it requires again more coding and setting up infrastructure. The whole public cloud journey of AWS has been aiming to simplify development and take load away by providing reusable components and libraries, and these launches go well with that agenda.