ELK - from zero to coding class hero

•Download as PPTX, PDF•

0 likes•23 views

The need for data visualization has never been greater and application logs can quickly become a big data forest of information. Can we get real-time indicators regarding application behavior and anticipate issues before our users start calling? This talk gives an example how to setup and use Elastic Stack for monitoring and alerting.

Technology

ELK – From zero to (coding class) hero
Josip Kovaček

Agenda
 Logs
 Elastic Stack
 Setup
 Monitoring
 Alerting

Logs
[ 2017-10-21 12:03:55.478, 8.8.8.8, Pero, /search, q=Changecon
ticket ]

Beats
 Lightweight data shippers
 Filebeat, Metricbeat, Packetbeat, Winlogbeat, Heartbeat
 60+ community beats

Logstash
 Input/output from 50+ destinations
 Extracts and transforms data
 30+ plugins for data manipulation

Elasticsearch
 Real time search and analytics engine
 Restful JSON API
 Scalable, reliable
 Index and archives

Kibana
 Queries Elasticsearch for data
 Predefined set of visualization types
 Dashboards, plugins

Setup
 Running each component manually
 Installing as a service
 Docker, Vagrant image
 Configure input/output and component specific parameters
 Configure “index pattern”

Setup
*beatname.template.json
curl -XPUT "http://localhost:9200/_template/filebeat?pretty" -
d@filebeat.template.json

Monitoring
 Application/integration endpoints heartbeat > HeartBeat
 System performance counters > MetricBeat
 Logs > FileBeat
 DB/performance counters > logstash-input-jdbc
 Spring Boot (Actuator) > HttpBeat

Alerting
 X-Pack
 ElastAlert – free alternative
 Alert via email, JIRA, Slack, Telegram, execute command...
 Rules:

Conclusion
 Benefits/drawbacks
 Learn from logs
 Getting bigger picture, detecting hard to find patterns
 Predicting upcoming service disruption
 Automated alerts, buying time when service fails

Q/A
 https://demo.elastic.co
 https://hub.docker.com/r/sebp/elk/
 https://github.com/Yelp/elastalert
 https://github.com/dzharii/awesome-elasticsearch

Thank you!
Conference and Media Partners

What's hot

OpenStack Ceilometer

openstackindia

ELK Stack

Phuc Nguyen

Our challenge for Bulkload reliability improvement

Satoshi Akama

Introduction openstack horizon

Jim Yeh

Analyzing MySQL Logs with ClickHouse, by Peter Zaitsev

Altinity Ltd

Adventures in Observability: How in-house ClickHouse deployment enabled Inst...

Altinity Ltd

Experiences in ELK with D3.js for Large Log Analysis and Visualization

Surasak Sanguanpong

OpenStack Log Mining

John Stanford

From Ceilometer to Telemetry: not so alarming!

Nicolas (Nick) Barcet

Reactive programming on Android

Tomáš Kypta

LowlaDB intro March 2015

Teamstudio

Migration to ClickHouse. Practical guide, by Alexander Zaitsev

Altinity Ltd

Clickhouse at Cloudflare. By Marek Vavrusa

Valery Tkachenko

nuclio Overview October 2017

iguazio

Supercharge your Analytics with ClickHouse, v.2. By Vadim Tkachenko

Altinity Ltd

Advancements in stream processing and OLAP (Online Analytical Processing) technologies have enabled faster insights into the data coming in, thus powering near real time decisions. This talk focuses on how Uber uses real time analytics for solving complex problems such as Fraud detection, Operational intelligence, Intelligent Incentive spend and showcases the corresponding infrastructure that makes this possible. I will go over the key challenges involved in data ingestion, correctness and backfill. We will also go over enabling SQL and Flink to support real-time decision making for data science and analysts.

Flink Forward SF 2017: Chinmay Soman - Real Time Analytics in the real World ...

Flink Forward

Apache Spark 2.2 ships with a state-of-art cost-based optimization framework that collects and leverages a variety of per-column data statistics (e.g., cardinality, number of distinct values, NULL values, max/min, avg/max length, etc.) to improve the quality of query execution plans. Leveraging these reliable statistics helps Spark to make better decisions in picking the most optimal query plan. Examples of these optimizations include selecting the correct build side in a hash-join, choosing the right join type (broadcast hash-join vs. shuffled hash-join) or adjusting a multi-way join order, among others. In this talk, we’ll take a deep dive into Spark’s cost based optimizer and discuss how we collect/store these statistics, the query optimizations it enables, and its performance impact on TPC-DS benchmark queries.

Cost-Based Optimizer in Apache Spark 2.2

Databricks

Kafka Summit NYC 2017 - Easy, Scalable, Fault-tolerant Stream Processing with...

confluent

Slides used for Apache Stratos (incubating) Fourth Hangout. Hangout video can be found at http://youtu.be/VtF9DVGKbTQ Website: http://stratos.incubator.apache.org Mailing List: Subscribe: dev-subscribe@stratos.incubator.apache.org Post (after subscription): dev@stratos.incubator.apache.org Social Media: Google+: https://plus.google.com/103515557134069849802 Twitter: https://twitter.com/ApacheStratos Facebook: https://www.facebook.com/apache.stratos LinkedIn: http://www.linkedin.com/groups?home=&gid=5131436

Apache Stratos (incubating) Hangout IV - Stratos Controller and CLI Internals

Isuru Perera

Apple Siri is the world's largest virtual assistant service powering every iPhone, iPad, Mac, Apple TV, Apple Watch, and HomePod. We use large amounts of data to provide our users the best possible personalized experience. Our raw event data is cleaned and pre-joined into an unified data for our data consumers to use. To keep the rich hierarchical structure of the data, our data schemas are very deep nested structures. In this talk, we will discuss how Spark handles nested structures in Spark 2.4, and we'll show the fundamental design issues in reading nested fields which is not being well considered when Spark SQL was designed. This results in Spark SQL reading unnecessary data in many operations. Given that Siri's data is super nested and humongous, this soon becomes a bottleneck in our pipelines. Then we will talk about the various approaches we have taken to tackle this problem. By making nested columns as first citizen in Spark SQL, we can achieve dramatic performance gain. In some of our production queries, the speed-up can be 20x in wall clock time and 8x less data being read. All of our work will be open source, and some has already been merged into upstream.

Making Nested Columns as First Citizen in Apache Spark SQL

Databricks

What's hot (20)

OpenStack Ceilometer

ELK Stack

Our challenge for Bulkload reliability improvement

Introduction openstack horizon

Analyzing MySQL Logs with ClickHouse, by Peter Zaitsev

Adventures in Observability: How in-house ClickHouse deployment enabled Inst...

Experiences in ELK with D3.js for Large Log Analysis and Visualization

OpenStack Log Mining

From Ceilometer to Telemetry: not so alarming!

Reactive programming on Android

LowlaDB intro March 2015

Migration to ClickHouse. Practical guide, by Alexander Zaitsev

Clickhouse at Cloudflare. By Marek Vavrusa

nuclio Overview October 2017

Supercharge your Analytics with ClickHouse, v.2. By Vadim Tkachenko

Flink Forward SF 2017: Chinmay Soman - Real Time Analytics in the real World ...

Cost-Based Optimizer in Apache Spark 2.2

Kafka Summit NYC 2017 - Easy, Scalable, Fault-tolerant Stream Processing with...

Apache Stratos (incubating) Hangout IV - Stratos Controller and CLI Internals

Making Nested Columns as First Citizen in Apache Spark SQL

Similar to ELK - from zero to coding class hero

Elk for applications on k8s

Che-Chia Chang

Elastic stack Presentation

Amr Alaa Yassen

As part of the 2018 HPCC Systems Summit Community Day event: Up first, Aramis Tanelus, American Heritage School, briefly discusses his poster, HPCC Systems Robotics Sensor Interface. Following, Rodrigo Pastrana and Miguel Vazquez present their breakout session in the Systems Tools track. Find out how to utilize ELK (a powerful log management stack comprised of Elastic Search, Logstash and Kibana) to visualize your HPCC Systems log data to help deliver actionable insights in real time, trend analytics, system monitoring and much more. In this session, we will walk through the log data extraction, visualization dashboard creation, and discuss related HPCC Systems and ELK insights. Rodrigo Pastrana is an Architect with the HPCC systems supercomputer focusing in platform integration and plug-in development. He has been a member of the HPCC core technology team for over five years and a member of the LexisNexis team for seven. Rodrigo is the principle developer of WsSQL, the HPCC JDBC connector, the HPCC Java APIs library and tools, and the Dynamic ESDL component. He has more than fifteen years of experience in design, research and development of state of the art technology including IBM’s embedded text-to-speech and voice recognition products, Eclipse’s device development environment. Rodrigo holds an MS and BS in Computer Engineering from the University of Florida and during his professional career has filed more than ten patent disclosures through the USPTO. Miguel Vazquez is a Consulting Software Engineer and has been with LexisNexis for 6 years. He brings 10+ years of application development to his role within the company. He oversees the front-end development for a number of items which include: ECL Watch, Dynamic ESDL, and Configuration Manager. He specializes in JavaScript and is a fan of the latest JavaScript trends.

Visualizing HPCC Systems Log Data Using ELK

HPCC Systems

MySQL Audit using Percona audit plugin and ELK

I Goo Lee

Introduction to ELK

Harshakumar Ummerpillai

Présentation ELK/SIEM et démo Wazuh

Aurélie Henriot

Workshop splunk 6.5-saint-louis-mo

Mohamad Hassan

Logging for Production Systems in The Container Era

Sadayuki Furuhashi

Serhii Matynenko "How to Deal with Logs, Migrating from Monolith Architecture...

LogeekNightUkraine

Exploring the Final Frontier of Data Center Orchestration: Network Elements -...

Puppet

In this session, Kiran demonstrates how to centralize all the CloudStack-related logs in one place using Elastic Search and generate beautiful dashboards in Grafana. This session simplifies the troubleshooting process involved with CloudStack and quickly helps to resolve the issue. ----------------------------------------- The CloudStack Collaboration Conference 2023 took place on 23-24th November. The conference, arranged by a group of volunteers from the Apache CloudStack Community, took place in the voco hotel, in Porte de Clichy, Paris. It hosted over 350 attendees, with 47 speakers holding technical talks, user stories, new features and integrations presentations and more.

Centralized Logging Feature in CloudStack using ELK and Grafana - Kiran Chava...

ShapeBlue

Apache Eagle Architecture Evolvement

Hao Chen

Alfresco monitoring with Nagios and ELK stack

Cesar Capillas

Play framework : A Walkthrough

mitesh_sharma

We're talking about serious log crunching and intelligence gathering with Elastic, Logstash, and Kibana. ELK is an end-to-end stack for gathering structured and unstructured data from servers. It delivers insights in real time using the Kibana dashboard giving unprecedented horizontal visibility. The visualization and search tools will make your day-to-day hunting a breeze. During this brief walkthrough of the setup, configuration, and use of the toolset, we will show you how to find the trees from the forest in today's modern cloud environments and beyond.

ELK Ruminating on Logs (Zendcon 2016)

Mathew Beane

Telegraf, InfluxDB’s native data collector, supports nearly 300 inputs and outputs. Using Telegraf, you can send data from a variety of systems, apps, databases and services in the appropriate format to InfluxDB. This session covers Telegraf plugins and InfluxDB client libraries as well as early access to release candidates. Alan Pope and Sebastian Spaink will highlight recent updates to Telegraf — including the new JSON and XML parsers!

Alan Pope, Sebastian Spaink [InfluxData] | Data Collection 101 | InfluxDays N...

InfluxData

WebCamp 2016: DevOps. Ярослав Погребняк: Gobetween - новый лоад балансер для ...

WebCamp

elk_stack_alexander_szalonnas

Alexander Szalonnas

Our applications are continuously sending log messages about their state. We usually have many different solutions/applications, which means, that we have many different logs. And that is never good. In short, your data is mutating, evolving and growing, but traditional analyses are no long in step with these changes. Business forte is all about sourcing, sculpting and analyzing this variety of data. The talk will focus on technology that makes this possible. URL: https://www.youtube.com/watch?v=Se2rVAg4EVs

Search and analyze data in real time

Rohit Kalsarpe

2015 03-16-elk at-bsides

Jeremy Cohoe

Similar to ELK - from zero to coding class hero (20)

Elk for applications on k8s

Elastic stack Presentation

Visualizing HPCC Systems Log Data Using ELK

MySQL Audit using Percona audit plugin and ELK

Introduction to ELK

Présentation ELK/SIEM et démo Wazuh

Workshop splunk 6.5-saint-louis-mo

Logging for Production Systems in The Container Era

Serhii Matynenko "How to Deal with Logs, Migrating from Monolith Architecture...

Exploring the Final Frontier of Data Center Orchestration: Network Elements -...

Centralized Logging Feature in CloudStack using ELK and Grafana - Kiran Chava...

Apache Eagle Architecture Evolvement

Alfresco monitoring with Nagios and ELK stack

Play framework : A Walkthrough

ELK Ruminating on Logs (Zendcon 2016)

Alan Pope, Sebastian Spaink [InfluxData] | Data Collection 101 | InfluxDays N...

WebCamp 2016: DevOps. Ярослав Погребняк: Gobetween - новый лоад балансер для ...

elk_stack_alexander_szalonnas

Search and analyze data in real time

2015 03-16-elk at-bsides

Recently uploaded

Portal Kombat : extension du réseau de propagande russe

中央社

In today's digital world, trust is key to customer relationships, but keeping it is a huge challenge. Customers are well-informed and empowered, quick to change brands if their trust is broken, even if it costs them more. This puts a lot of pressure on organizations to handle trust and safety issues with great care and transparency. The challenge, however, is real. Fragmented solutions have left privacy, legal, and security teams in a perpetual cycle of catch-up, struggling to update privacy notices, manage customer data rights, and answer lengthy security questionnaires—all while trying to prove ROI to the business. It's a thankless job, filled with repetition, tedious tasks, and constant interdepartmental coordination. Combine this with fast regulatory changes and the quick evolution of AI, and it becomes overwhelming. Join this webinar to learn more about TrustArc's new innovative solution Trust Center, the only unified, no-code online hub for trust and safety information built for privacy, security, compliance, and legal teams. Trust Center streamlines your path to compliance, shortens the pre-sales cycle, and reduces both legal and regulatory risks, saving time, effort, and cost. This webinar will review: - Why companies are building unified Trust Centers for a robust privacy program. - How unified Trust Centers streamline sales cycles, ensure regulatory compliance, and reduce operational bottlenecks. - How compliance, legal, security, GRC, and privacy teams benefit from a unified Trust Center in terms of needs, pains, and outcomes. - How TrustArc Trust Center saves time and work while reducing legal, reputational, and compliance risk by effectively managing policies, notices, terms, and disclosures, and providing real-time updates on subprocessors.

TrustArc Webinar - Unified Trust Center for Privacy, Security, Compliance, an...

TrustArc

Vector Search @ sw2con for slideshare.pptx

jbellis

TEST BANK For, Information Technology Project Management 9th Edition Kathy Sc...

marcuskenyatta275

ERP Contender Series: Acumatica vs. Sage Intacct

BrainSell Technologies

Explore the latest trends and insights on JavaScript usage with Pixlogix's informative blog. Discover key statistics and facts about JavaScript's role in web development, its popularity among developers, and its impact on modern websites. Stay updated with the evolving landscape of JavaScript frameworks and libraries, and learn how they're shaping the future of web development. Gain valuable insights to enhance your JavaScript skills and stay ahead in the digital realm.

JavaScript Usage Statistics 2024 - The Ultimate Guide

Pixlogix Infotech

WebRTC and SIP not just audio and video @ OpenSIPS 2024

Lorenzo Miniero

Because observability is such a broad topic – and often something we learn on the job – it can feel like there’s too much to learn at once. But you don’t have to tackle everything and can start with the basics and build from there! Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack. No matter what tooling is in place, there are still observability fundamentals that developers should know. That’s why I’ve put together a primer on the different telemetry types, when to use them, how to understand the data journey, and what to look for in time series graphs.

Observability Concepts EVERY Developer Should Know (DevOpsDays Seattle)

Paige Cruz

Design Guidelines for Passkeys 2024.pptx

FIDO Alliance

Overview of Hyperledger Foundation

Hyperleger Tokyo Meetup

In the ever-evolving landscape of data management, Zero-ETL is an approach that is reshaping how businesses handle and integrate their data. This webinar explores Zero-ETL, a paradigm shift from the traditional Extract, Transform, Load (ETL) process, offering a more streamlined, efficient, and real-time data integration method. We will begin with an introduction to the concept of Zero-ETL, including how it allows direct access to data in its native environment and real-time data transformation, providing up-to-date information with significantly reduced data redundancy. Next, we'll take you through several demonstrations showing how Zero-ETL can deliver real-time data and enable the free movement of data between systems. We will also discuss the various tools that support all aspects of Zero-ETL, providing attendees with an understanding of how they can adopt this innovative approach in their organizations. Lastly, the session will conclude with an interactive Q&A segment, allowing participants to gain deeper insights into how Zero-ETL can be tailored to their specific business needs and how they can get started today. Join us to discover how Zero-ETL can elevate your organization's data strategy.

The Zero-ETL Approach: Enhancing Data Agility and Insight

Safe Software

In the dynamic field of DevOps, the quest for efficiency and productivity is endless. This talk introduces a revolutionary toolkit: Large Language Models (LLMs), including ChatGPT, Gemini, and Claude, extending far beyond traditional coding assistance. We'll explore how LLMs can automate not just code generation, but also transform day-to-day operations such as crafting compelling cover letters for TPS reports, streamlining client communications, and architecting innovative DevOps solutions. Attendees will learn effective prompting strategies and examine real-life use cases, demonstrating LLMs' potential to redefine productivity in the DevOps landscape. Join us to discover how to harness the power of LLMs for a comprehensive productivity boost across your DevOps activities.

ChatGPT and Beyond - Elevating DevOps Productivity

VictorSzoltysek

Discover the top CodeIgniter development companies that can elevate your project to new heights. Our blog explores the best firms known for their expertise in CodeIgniter framework development. From robust web applications to scalable solutions, these companies deliver excellence. Whether you're a startup or an enterprise, find the perfect match for your development needs on Top CSS Gallery's blog.

Top 10 CodeIgniter Development Companies

TopCSSGallery

Hyatt driving innovation and exceptional customer experiences with FIDO passw...

FIDO Alliance

Introduction To Iamnobody89757 the vast expanse of the online realm, where anonymity and individuality intertwine, a phenomenon has emerged that captivates the collective curiosity – Iamnobody89757. This enigmatic entity, once a mere username, has transcended its humble origins to become a symbol of the intricate dance between privacy and expression in the digital age. Through this exploration, we delve into the origins, evolution, and far-reaching implications of this intriguing moniker, shedding light on the profound questions it raises about our digital selves. The Origins of iamnobody89757 The origins of iamnobody89757 are shrouded in the virtual mists of the wide internet. The term gained popularity on a niche discussion group that examined the most puzzling puzzles on the internet. In this instance, iamnobody89757 surfaced as a mysterious character who captivated other users with a conversation that was both mysterious and perceptive. These initial interactions were nuanced, filled with veiled references and subtle hints that painted a picture of someone—or something—with an intricate understanding of the digital domain’s darker corners. Although initially dismissed by many as just another anonymous user, the accuracy of certain predictions shared by iamnobody89757 soon captured the collective imagination. The iamnobody89757 enigma began with this shift from an unnoticed commenter to a fascinating subject, laying the groundwork for a growing tale that would weave its way through the fabric of online communities. The Birth of a Digital Persona Tracing the Roots The inception of Iamnobody89757 can be traced back to the early days of online forums and chat rooms, where users sought a delicate balance between anonymity and connectivity. In a world where personal information was a coveted commodity, this seemingly random assemblage of words and numbers became a shield, protecting the user’s identity while allowing them to engage in discourse without fear of judgment or repercussions.

“Iamnobody89757” Understanding the Mysterious of Digital Identity.pdf

Muhammad Subhan

Continuing Bonds Through AI: A Hermeneutic Reflection on Thanabots

Leah Henrickson

Intro to Passkeys and the State of Passwordless.pptx

FIDO Alliance

At Skynet Technologies, our team of accessibility experts performs automated, semi-automated, and manual audits of websites and web applications as per WCAG 2.2 level AA, ADA, and section 508. Based on evaluations of the accessibility compliance level of the website’s UI, design, source code, navigation, interactive elements, and overall usability, we will provide a digital accessibility evaluation report with in-depth details of potential accessibility barriers and remediation recommendations. Get a manual website WCAG audit (2.0, 2.1, 2.2 level AA) for a small website: 10 pages: $2,500 within 7 business days 30 pages: $7,500 within 14 business days 50 pages: $12,500 within 28 business days For medium websites: 100 pages: $25,000 within 70 business days For larger websites or audits of all pages, please reach out hello@skynettechnologies.com.

Human Expert Website Manual WCAG 2.0 2.1 2.2 Audit - Digital Accessibility Au...

Skynet Technologies

Tales from a Passkey Provider Progress from Awareness to Implementation.pptx

FIDO Alliance

Harnessing Passkeys in the Battle Against AI-Powered Cyber Threats.pptx

FIDO Alliance

Recently uploaded (20)

Portal Kombat : extension du réseau de propagande russe

TrustArc Webinar - Unified Trust Center for Privacy, Security, Compliance, an...

Vector Search @ sw2con for slideshare.pptx

TEST BANK For, Information Technology Project Management 9th Edition Kathy Sc...

ERP Contender Series: Acumatica vs. Sage Intacct

JavaScript Usage Statistics 2024 - The Ultimate Guide

WebRTC and SIP not just audio and video @ OpenSIPS 2024

Observability Concepts EVERY Developer Should Know (DevOpsDays Seattle)

Design Guidelines for Passkeys 2024.pptx

Overview of Hyperledger Foundation

The Zero-ETL Approach: Enhancing Data Agility and Insight

ChatGPT and Beyond - Elevating DevOps Productivity

Top 10 CodeIgniter Development Companies

Hyatt driving innovation and exceptional customer experiences with FIDO passw...

“Iamnobody89757” Understanding the Mysterious of Digital Identity.pdf

Continuing Bonds Through AI: A Hermeneutic Reflection on Thanabots

Intro to Passkeys and the State of Passwordless.pptx

Human Expert Website Manual WCAG 2.0 2.1 2.2 Audit - Digital Accessibility Au...

Tales from a Passkey Provider Progress from Awareness to Implementation.pptx

Harnessing Passkeys in the Battle Against AI-Powered Cyber Threats.pptx

ELK - from zero to coding class hero

1. ELK – From zero to (coding class) hero Josip Kovaček

2. Elk => Elastic Stack

3. Agenda  Logs  Elastic Stack  Setup  Monitoring  Alerting

4. Logs [ 2017-10-21 12:03:55.478, 8.8.8.8, Pero, /search, q=Changecon ticket ]

5. Logs

6. Logs

7. Logs

8. Elastic Stack

9. Elastic Stack Plugins…Lots of plugins

10. Elastic Stack

11. Beats  Lightweight data shippers  Filebeat, Metricbeat, Packetbeat, Winlogbeat, Heartbeat  60+ community beats

12. Logstash  Input/output from 50+ destinations  Extracts and transforms data  30+ plugins for data manipulation

13. Elasticsearch  Real time search and analytics engine  Restful JSON API  Scalable, reliable  Index and archives

14. Kibana  Queries Elasticsearch for data  Predefined set of visualization types  Dashboards, plugins

15. Setup  Running each component manually  Installing as a service  Docker, Vagrant image  Configure input/output and component specific parameters  Configure “index pattern”

16. Setup logstash.yml configuration

17. Setup *beatname.template.json curl -XPUT "http://localhost:9200/_template/filebeat?pretty" - d@filebeat.template.json

18. Monitoring  Application/integration endpoints heartbeat > HeartBeat  System performance counters > MetricBeat  Logs > FileBeat  DB/performance counters > logstash-input-jdbc  Spring Boot (Actuator) > HttpBeat

19. Alerting  X-Pack  ElastAlert – free alternative  Alert via email, JIRA, Slack, Telegram, execute command...  Rules:

20.

21. Alerting

22. Conclusion  Benefits/drawbacks  Learn from logs  Getting bigger picture, detecting hard to find patterns  Predicting upcoming service disruption  Automated alerts, buying time when service fails

23.

24. Q/A  https://demo.elastic.co  https://hub.docker.com/r/sebp/elk/  https://github.com/Yelp/elastalert  https://github.com/dzharii/awesome-elasticsearch

25. Thank you! Conference and Media Partners

ELK - from zero to coding class hero

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to ELK - from zero to coding class hero

Similar to ELK - from zero to coding class hero (20)

Recently uploaded

Recently uploaded (20)

ELK - from zero to coding class hero