Elk logging. ELK stands for Elasticsearch, Logstash, and Kibana. You need to use _doc or _create in order to create the Index on Kibana. Finally, it controls users and their level of access in the ecosystem. Overview. io built Cloud SIEM, a fully featured SIEM built around ELK technology Oct 29, 2020 · For the next step, I have executed the same tracks with the HTTP server log data using the following configuration: Volumes: 31. Publish the logs based on indexing. Kibana is a web interface, which accesses the logging data form Elasticsearch and visualizes it. Beats ship data that conforms with Elastic Common Schema (ECS), and if you want more processing muscle, they can forward to Logstash for transformation and parsing. Log All the Things. Feb 1, 2016 · Centralized logging can be very useful when attempting to identify problems with your servers or applications, as it allows you to search through all of your logs in a single place. And now we have a dedicated Observability solution. log at multiple servers is not a big fun And here Elastic stack (ELK) comes to play. Sumo Logic offers a complete set of log management tools for the entire stack, whether cloud, on-premises, or hybrid. 04 Centralized logging can be very useful when attempting to identify problems with your servers or applications, as it allows you to search through all of your logs in a single place. Join now. Learn the fundamentals of observability (logging, metrics, APM), security, SIEM, ML, Log Management Purpose-Built to Reduce Costs. Logging is a great instrument for ‘debugging’ applications on production. Logs are provided for each Kubernetes control plane component instance. The trio, which was once separate, joined together to give users the ability to run log analysis on top of open sourced software that everyone can run for free. You can’t ship production software without good logging during the development process and while in production. Learn what is the ELK Stack, why it is popular, and how to install and configure it. In this tutorial, I describe how to setup Elasticsearch, Logstash and Kibana on a barebones VPS to analyze NGINX access logs. name: filebeat. [1] Elk has a population of 208. slack. Many Loggly customers have evaluated the Elastic Stack on the road to Mar 18, 2024 · ELK is an acronym that stands for Elasticsearch, Logstash, and Kibana. It is a rest-based service that listens to and publishes the logs to ELK or Splunk. ELK is quickly overtaking existing proprietary solutions and becoming companies Nov 7, 2022 · Elastic Stack. By default, Kibana comes with histograms, line graphs, pie charts, sunbursts, and more. Oct 29, 2017 · ( ELK Stack Training - https://www. In recent months, the engineering team here at Codementor started building our own logging system. And the maximum indexing throughput for the http server log data is 220K events per Configuring logging actions edit. Here is our configuration file logback. This manual shows how to configure core components to ship, aggregate and analyse logs. com/TechPrimersFacebook Jun 21, 2021 · ELK stack provides centralized logging in order to identify problems with servers or applications. The Elasticsearch Relevance Engine ™ (ESRE) is designed to power artificial intelligence-based search applications. conf) under a new directory called elasticIn the Dockerfile, we are going to use Jul 9, 2015 · The ELK Stack is a widely used and popular open-source data analytics and log management solution. 00 per location per month (per Elastic Stack) for up to 1k simultaneous test run capacity (~2. KUBE_LOGGING_DESTINATION=elasticsearch. Slack Community: https://techprimers. Simply type “System” in the search to select it. Elk Falls Logging. g. See farther. Configure logging. May 16, 2023 · Together, these three components form the ELK stack, which is widely used for log management, monitoring, and troubleshooting in various applications and systems. The large volumes of logs, metrics, and traces generated by scaling cloud environments can be overwhelming, but they must be collected to identify and respond to production issues or other signals showing business or application issues. A typical ELK pipeline in a Dockerized environment looks as follows: Logs are pulled from the various Docker containers and hosts by Logstash, the stack’s workhorse that applies filters to parse the logs better. They sit on your servers, with your containers, or deploy as functions — and then centralize data in Elasticsearch. Using Fiddler. For the source to send its logs, it needs an agent. Not only is it critical for diagnosing and resolving bugs and production issues, but it’s increasingly valuable for customer insights. ElasticSearch 是整體系統的核心部分,是一個非關聯式資料庫以JSON格式儲存資料,擁有一個非常厲害的 The ELK Stack is the more common name for a suite of components used to monitor and observe your infrastructure. comTwitter: https://twitter. Quản lý log tập trung: Thay vì phải lọ mọ vào Logs UI is a specialized tool for exploring logs. Use ESRE to apply semantic search with superior relevance out of the box (without domain adaptation), integrate with external large language models (LLMs), implement hybrid search, and use third-party or your own transformer models. Also, you might need to update the listener URL, depending on the region in which your account is hosted. Mar 27, 2017 · If you’re using the ELK stack, this method allows you to remove Logstash and to instead use Beats to ship logs directly to Elasticsearch for processing and indexing. It processes the events and later stores it in Elasticsearch. Log analytics is the process of searching, investigating, and visualizing data generated by IT systems, which is stored as time-sequenced logs. Elasticsearch is at the core of the stack. 1 Jan 15, 2023 · Decoding log management: Splunk and ELK stack face-off. Key Features: Plain and simple. Go to the cogwheel in the top right corner of the Logz. Elastic offers free introductory training for the Elastic (ELK) Stack - Elasticsearch, Kibana, Beats and Logstash. This can help them resolve application and system issues Best Practices for Managing Elasticsearch Indices. When you select the Add System you’ll be prompted to walk through how to ingest your system logs. Forests have incredible ecological, social, cultural, and spiritual significance; sustainable timber harvesting methods exist to reduce negative deforestation impacts, but they are Apr 16, 2020 · ELK, elasticsearch ,logstash, kibana cluster can help startup firms in logging monitoring and alerting need. It allows you to search all the logs in a single place. See full list on sematext. The Logs app in Kibana enables you to search, filter, and tail all your logs ingested into Elasticsearch. It has 10 predetermined fields. Supports different formats to publish the logs. Dig deeper. Logstash Configuration. Now, we need to configure Logstash to read data from log files created by our app and send it to ElasticSearch. With 10+ years of experience in building a centralized logging solution as well as being ELK consultants for hundreds of companies, we can design, optimize and troubleshoot logging setups through all steps: Log generation: The log format and initial destination options have important trade-offs. To summarize, the ELK stack provides a logging solution based on three components: Elasticsearch (log analysis), Logstash (log collection and processing), and Kibana (visualization). It has all potential features similar to new relic. Logstash ingests and collects log data Feb 17, 2023 · ELK Stack is a powerful tool for collecting, analyzing, and visualizing log data. It also helps to find issues in multiple Apr 20, 2021 · The situation in the Elk Valley demonstrates what can happen in other areas of BC if large expanses of private land get into the hands of logging companies. Introduction to logging with the ELK Stack: A primer for beginners. Key things to note when choosing between Splunk and Elastic Stack 1. Jan 18, 2023 · logstash. Thats why Logz. Explore Elastic Stack (Elasticsearch, Logstash, Kibana, Beats) features like Elasticsearch security, alerting, monitoring, cloud deployment, analytics, full-text search, SIEM, visualizations, containe Dec 4, 2023 · To download and install Elasticsearch, follow these steps: 1. . log Configure Logstash to Understand Spring Boot’s Log File Format: This is the most tricky and important part of all as this step is like the bridge between the Spring The next step is to create a Cloud Foundry logging service that will drain the logs to syslog and then bind this service to our application. Centralized data visualization allows you to spot developing trends and disarm any errors before they occur or during damage control, finding the root cause faster. conf file is a simple configuration that sets up Logstash to listen for incoming JSON data on TCP port 5000 and send that to an Elasticsearch instance. Toggle filters on and off to maintain complete control of data flow and costs. Join us as we go over the basics and show you how to get started using the Elastic Stack. Nov 1, 2021 · Stack là gì? Trước khi tìm hiểu ELK Stack là gì, chúng ta cần hiểu thế nào là logging. The following snippet shows a simple logging action definition: The id of the action. co/elk-stack-training )This Edureka tutorial on What Is ELK Stack will help you in understanding the fundamentals Sep 25, 2018 · Elastic ELK Stack. The ELK Stack allows you to handle all of your log data and analyze it in real-time. We run Kibana by the following command in the bin folder of Kibana. While Elasticsearch can require some significant oversight to scale efficiently, there are capabilities that simplify ELK operations – one area Python comes with a logging module that is very flexible and easy to use. This map gives you the opportunity to do just about anything that FS22 has to offer. elk-example. It consists of three open-source components: Elasticsearch, Logstash, and Kibana. The Elastic Stack is a powerful option for gathering information from a Kubernetes cluster. The logging section of the filebeat. cnf. Log Aggregation Utility. Using Elastic Agent integrations, you can ingest logs from Kubernetes, MySQL, and Understanding the Pipeline. ensure that the changes are saved: save sys config partitions all Add Logging Profile to virtual server with the policy. In the ELK stack, Logstash extracts the logging data or other events from different input sources. io account. Learn faster. The Elastic stack addresses the industry gap with log data. But our ELK log management total cost of ownership (TCO) analysis shows that a business with average daily log volumes growing from 100 GB to 800 GB over a four-year period will likely spend close to $4. If you don’t want the token to expire then use ApiKey . For those unaware, ELK is an integrated solution which consists of 3 components. IT, operations, and application teams rely on them to manage well-intentioned users and keep malicious actors at bay, while executives and customers can rest easy knowing data stored in the Elastic Stack is safe and secure. Sumo Logic. Log files are an essential data source because of the information about the health of your systems and applications. It is also useful because it allows you to identify issues that span multiple servers by correlating their logs during a specific time frame. Ingestion and pipelines In Elasticsearch 5. Elastic Stack security features give the right access to the right people, with most features at no additional cost. Let’s get started. sh and 10-logstash. If logging is not explicitly configured the file output is used. Plus, gaining additional metrics about the health and usage of systems gives your team a strong competitive advantage. cnf’ configuration file: $ sudo vim /etc/mysql/my. Elasticsearch: Stores and indexes transformed data from Logstash. Join us as we go over the basics and show you how to get started using the Elastic Stack for your log and metrics analytics — the first steps on the path to Mar 29, 2020 · The ELK Stack (Elasticsearch, Logstash, and Kibana) is the world’s most popular open-source log analysis platform. 45. It acts as a highly efficient search and analytics engine May 6, 2020 · The ELK stack is a group of open-source software packages used to manage logs. Các bạn verify service name bằng lệnh sau: The Amazon EKS cluster control plane nodes are integrated with CloudWatch and you can turn on logging for specific control plane components. bin\kibana. You can use the ELK Stack to manage all of your log data and analyze everything in real-time. Splunk is known for its advanced features, which is an expensive affair for smaller companies to afford. Alerting inside the Elastic Stack also supports a powerful webhook output letting you tie into additional third-party systems that matter to your organization. ELK Stack là tập hợp 3 phần mềm đi chung với nhau, phục vụ cho công việc logging. 1, you can think of a pipeline as a factory line of processors, where each processor has a single task to perform on the data (for Logging Consulting. Open your preferred web browser and visit the official Elasticsearch download page. io interface, then click Settings -> General. The logging system can write logs to the syslog or rotate log files. Action-specific attributes are specified using the logging keyword. We are going to create the following three files (Dockerfile, setup-elastic. Mar 7, 2024 · ELK stack also competes with market leaders like Splunk and is extremely popular with smaller companies. A Cost Comparison: ELK vs Proprietary Log Analytics. Instead of having to log into different servers, change directories, and tail individual files, all your logs are available in the Logs app. Discover is a tool that focuses on rapid consumption of Elasticsearch data, including logs, with a standardized query language. Beats are great for gathering data. Like many logging libraries, Python can log at multiple levels (e. This guide shows you how to install the ELK stack (Elasticsearch, Logstash, and Kibana) on CentOS 8 server. It is located on the coast at the crossroads of State Route 1 and Philo-Greenwood Road. Logstash dynamically transforms and prepares your data regardless of format or complexity: Ease overall processing, independent of the Nov 24, 2021 · The ELK stack with basic features is open source, which makes it a cost-efficient solution for startups and established businesses alike. Once researchers know where elk are, aerial photographs will be taken to show the ground cover elk prefer at different times of the year and different biological periods. Jul 15, 2019 · ELK is deployed together with Wazuh for storing and analyzing log data. There are a couple of popular ways of capturing this information. This stack is commonly used for centralizing and analyzing large volumes of log and event data. But when we defined what a SIEM system actually is, a long list of components was listed in addition to log management. Nov 6, 2020 · ELK 是由三個工具組成,Elasticsearch (E) 、Logstash (L) 、Kibana (K) 組成的Log 過濾、儲存、分析、視覺化系統,另外我們還需要一個叫Beat的工具來擔任Log的採集工具。. Log analytics takes log monitoring one step further, allowing observability teams to discover patterns and anomalies across an organization. 1GB; Document: 247,249,096; Avg document size: 0. May 28, 2020 · I have implemented a full ELK stack in my company in the past year. , INFO or ERROR), format the log output in various ways, and write to different destinations (e. Comprised of Elasticsearch, Kibana, Beats, and Logstash, the Elastic Stack provides a The first is your Logz. Jul 21, 2022 · replicas: 1. Số lượng replicas cho bài lab thì chỉ cần 1 là đủ. Jan 6, 2023 · Like the ELK stack, Graylog is an open-source log management tool, using Elasticsearch as its storage. io, a SaaS logging and observability platform. Starting at . e. com ELK Stack is a stack of Elasticsearch, Logstash, and Kibana, three popular projects for log analytics and search. 79:5244 { } } } } 3. 3. 4. Elastic Security Quick Start. Unlock exclusive posts and join a community of 39 members. Lightweight tests are $28. ). Sep 29, 2021 · Kibana also monitors the ELK Stack's health. The advantages of using ELK and not implementing our own centralized logging solution would be: Not needing to re-invent the wheel- There is already a product that is doing just that. Extend your alerts by connecting them to actions that use built-in integrations for email, webhooks, IBM Resilient, Jira, Microsoft Team, PagerDuty, ServiceNow, and Slack. Logging isn’t optional. First, we need to configure MySQL to write general and slow query log files because those configurations are disabled by default. We need to create a logstash configuration file so that it listen to the log file and push log messages to elastic Feb 24, 2019 · Docker ELK Structure. Yielding an optimal number of 32 clients. Sep 27, 2018 · logging. Log monitoring. In this virtual event we'll go over the benefits of a log management solution, challenges you'll likely encounter along the way, and some tips Why ELK Stack? Với các hệ thống hoặc ứng dụng nhỏ, ta không cần giao mổ trâu đi giết gà làm gì, cứ ghi log ra file hoặc stdout của hệ thống là được. Kubernetes supports sending logs to an Elasticsearch endpoint, and for the most part, all you need to get started is to set the environment variables as shown in Figure 7-5: kubernetes. Add the Elastic Authorization Key . 2 million to operate and maintain a production-grade Configure logging edit. Logstash forwards the logs to Elasticsearch for indexing, and Kibana analyzes and visualizes the data. Then security practitioners took notice and started using the ELK Stack to power their security analytics, and now we have a free and open SIEM. Ba phần mềm này lần lượt là : Elasticsearch: Cơ sở dữ liệu để lưu trữ, tìm kiếm và query log. First, you’ll add an Elastic agent, add and configure your integration, then start sending logging data into Elastic. The Elastic stack provides a robust platform for performance and security monitoring, ensuring maximal uptime and regulation compliance. Do cả bộ ELK mình đều cài chung trên một namespace do đó chỉ cần khai báo (service-name):port là đủ. ELK stack. Whilst developing with Elasticsearch using NEST, it can be extremely valuable to see the requests that NEST generates and sends to Elasticsearch, as well as the responses returned. Jan 29, 2019 · Unzip the files and put all three in the project folder. file {. yml config file contains options for configuring the logging output. To do this, first open the ‘my. What is the ELK stack? ELK stands for Elasticsearch, Logstash and Kibana. Apr 30, 2020 · The ELK Stack (Elasticsearch, Logstash, and Kibana) is the world’s most popular open-source log analysis platform. But one thing to keep in mind is the fact that users are expected to manage and maintain the stack on their own. 2 Synthetic Monitoring browser tests are $0. หลักการทำงานของ ELK stack เริ่มจาก fileBeat จะเก็บรวบรวม log file ของเราแล้วก็ Apr 6, 2020 · Together, Elasticsearch, Logstash, and Kibana became the ELK Stack (now Elastic Stack) and sowed the seeds of a new use case (logging). Then, we need to set the threshold for creating logs. Using OnRequestCompleted. Nói một cách đơn giản, dễ hiểu thì logging là công cụ đơn giản và mạnh mẽ giúp ghi lại toàn bộ dữ liệu và các hoạt động trên hệ thống, hỗ trợ quá trình kiểm tra trở nên thuận tiện và dễ dàng hơn. Find out the advantages of OpenSearch and OpenSearch Dashboards, the open source versions of Elasticsearch and Kibana, and how to use them with Logz. Use data views to view and query logs within Logs UI or Discover. Replace the URL and specify the index you want to use (e. For many organizations, centralizing and storing logs to perform log analytics is the first step in the path to observability – even if they don't realize that they've embarked on a journey. In fact, logging something to a file is as simple as this: Dec 19, 2017 · This video covers what is ELK stack and what are they used for. Configure Logstash. Unlock exclusive posts. May 17, 2020 · ELK Elastic stack is a popular open-source solution for analyzing weblogs. Jul 26, 2017 · Elastic Stack (aka ELK Stack) appears on many companies’ log management short lists. If you get stuck take a look at this guided tour for installing the Many of you already know the benefits of the ELK stack and why so many teams are using it. Oct 28, 2016 · 1. But people still tend to call it ELK; It is a distributed monitoring solution suiteable for almost any structured and unstructured data source, but not limited to log; It supports centralized logging/metric/APM monitoring; It is open source and can be extended easily. Similarly, Elasticsearch is setup like this: bin\elasticsearch. Jun 25, 2020 · $ grep "something" file. A typical a logfile data file is a text record of every event in the system with a detailed description and the exact time when it occurred. As data travels from source to store, Logstash filters parse each event, identify named fields to build structure, and transform them to converge on a common format for more powerful analysis and business value. Learn how they work together to solve log analytics, security, and observability problems, and how to choose the right solution for your needs. Join the O'Reilly online learning platform. There are many agents that can do this role like Logstash, Fluentd, and Filebeat. To collect, monitor, and analyze this data, many teams If log management and log analysis were the only components in SIEM, the ELK Stack could be considered a valid open source solution. Here’s what we learned. ELK là một lựa chọn cực kì phù hợp, được nhiều công ty lớn như Netflix, Linkedin, Medium lựa chọn vì những lý do bên dưới! Các công ty sử dụng ELK Stack Vậy ELK Stack có gì hay ho? Dec 9, 2020 · ELK Stack is a combination of Elasticsearch, Logstash, and Kibana, and is the most popular open-source log analysis platform. , console or file). The project was huge and took a lot of time to properly implement. It enables you to search, filter, and tail all the logs you have ingested into Elasticsearch. Setting up ELK. Together, these three components provide a powerful, integrated solution for managing large volumes of data, offering real-time insights and a comprehensive analytics suite. log has been created and do a couple of visits to the endpoints and verify that logs are getting added in the log file. $3 /month. In this article, I will provide a beginner's guide to ELK Stack, including an overview of each component and how they work together to help you manage your logs more effectively. . Instance type usage-based pricing. file=application. Albion, Little River, and Mendocino lie to the north, and Manchester and Point Arena to the south. It also supports highly available, scalable alerting via email, webhooks, Jira, Microsoft Teams, Slack, and other tools. Other well-known platforms in the realm of log The Elastic Stack (also known as the ELK Stack) is used across a variety of use cases — from troubleshooting errors in your application metrics to investigating security threats in your logs to powering the search box on your websites and applications. io token, which you can find in your Logz. From farming in the river valley and the high plains, logging in the densely forested mountains and mining across the map. The term “ELK” stands for the stack’s three initial open-source components: Elasticsearch, Logstash, and Kibana. Logging. Feb 2, 2023 · ELK. Aug 12, 2020 · Add the HTTP log4j appender to your Mule application (snipped below). Since the time that Elastic launched the ELK stack in 2015 and renamed it Elastic Stack earlier this year, it has generated a fair amount of interest from developers and DevOps teams interested in ELK Logging. 1 Based on cloud production config, 120 GB storage / 2 zones. Apr 30, 2022 · It is a large river valley with mountains on one side and on the other side large open high plains. Unlike the ELK stack, which is built from individual components (Elasticsearch, Logstash, Kibana), Graylog is built as a complete package that can do everything. Join now Jan 17, 2024 · When used together, these tools form a powerful platform for working with large datasets in real-time. 2. Companies often employ the Elastic/ELK stack log analysis, real-time analytics, and other use cases where searching, analyzing and visualizing large datasets is important. Data Optimization Hub provides a single place to inventory all incoming data, identify unused data, and filter out all unneeded log data – helping customers realize 30-50% cost reductions from filtered data. Next, uncomment and edit the following lines: Dec 1, 2017 · Tutorial Series: Centralized Logging with ELK Stack (Elasticsearch, Logstash, and Kibana) On Ubuntu 14. Aug 2, 2023 · ELK is the most well-known of all the log analytics stacks given its wide adoption, excellent support and the use of open-source commitments. AWS manages the health of your control plane nodes and provides a service-level agreement (SLA) for the Kubernetes endpoint. In this case, it’s a TCP input with the following options: port: the port that Logstash should listen on. Jan 5, 2024 · 2. Review findings, benchmark findings against CIS controls, and follow remediation guidance to drive rapid improvement. Logstash aggregates the logs, transforms/ parses data -> Elasticsearch stores and indexes incoming logstash data -> Kibana analyses and visualizes the data from Elasticsearch. Next, select Windows from the dropdown list as your platform and click the Windows button to download the Elasticsearch ZIP package. It’s typically used for server logs but is also flexible (elastic) for any project that generates large sets of data. Sep 21, 2020 · create security log profile dc_show_creation_elk application add { dc_show_creation_elk { logger-type remote remote-storage splunk servers add { 10. ‘ELK’ stands for Elasticsearch, Logstash, and Kibana, which are the three core components of the stack. You configure logging actions in the actions array. conf: input {. ELK stack is a simple tool with strong log management and analytical features offered at a much lower cost. Logstash - ELK Stack. input: the input that Logstash should listen to. We put the popular ELK (Elasticsearch, Logstash, Kibana) stack to the test and learned how to build a good logging system through this process. 6 billion tests per month). Aug 23, 2022 · The ELK Stack is a collection of components that are used to monitor and observe your infrastructure. Create the service with (replace <logstash-server> with the IP of the server where your Logstash instance is installed): $ cf cups log-drain -l syslog://<logstash-serve>:5000. Trong đó elasticsearch-master là tên service của elasticsearch. Geography. If you find out an issue — with good application-level logs you can find out the reason effortlessly. 0. mule-logs). Aug 6, 2020 · In order to parse this with ELK, you’ll probably want to forward this log to a centralized log server using your solution of choice (filebeat, wazuh agent, etc. Tuy nhiên với hệ thống lớn, gồm nhiều services lại là câu chuyện khác. A smaller temperature logging module will transmit the air temperature with GPS location data, allowing researchers to track what type of habitat elk seek at certain temperatures. It is located 22 miles (35 km) south of Fort Bragg, [2] at an elevation of 135 feet (41 m). The acronym “ELK” stands for the original three open source components that made up the stack: Elasticsearch, Logstash, and Kibana. 0123 per test run (metered in 60 second increments). Logstash: Tiếp nhận log từ nhiều nguồn, sau đó xử lý log và ghi dữ liệu vào Elasticsearch Oct 16, 2023 · The log aggregation service was designed to publish the logs generated by the Mule application to log aggregators like ELK and Splunk. Watch now. Oct 1, 2022 · Go to the application root directory and verify that the log file i. Aug 3, 2018 · Published Feb 05, 2018 Last updated Aug 03, 2018. I don't dwell on details but instead focus on things you need to get up and running with ELK-powered log analysis quickly. This article discusses elk architecture and implementation details. An optional transform to transform the payload before executing the logging action. In my Jan 4, 2024 · Finally, let’s make sure the app has permissions to access logging directory: sudo chmod a+rwx /var/lib/tomcat8/logback. 8 KB; Optimal bulk size is 16K documents. path: /var/log/filebeat. The Elastic Stack (also known as the ELK Stack) is used across a variety of use cases — from observability to security, from enterprise search to business analytics. ELK is quickly overtaking existing proprietary solutions and becoming The first choice for companies shopping for log analysis and management solutions. 1. Step 1 — Set up Kibana and Elasticsearch on the local system. May 12, 2016 · Why Elastic Stack / ELK Is a Trending Topic in Log Management. Jan 8, 2020 · ELK stack works by receiving log data from different sources. edureka. Elasticsearch is a powerful distributed search engine that has, over the years, grown into a more general-purpose NoSQL storage and analytics tool. Lúc này, người ta bắt đầu áp dụng centralized logging, tức ghi log tập trung vào 1 chỗ. da on sw hm dm vf iw ow ha ka