Kevin Liu's Blog || Technical || Travel

🌐 中文版：繁體中文 IntroHaving grown up in Taipei for years without visiting Qixing Mountain’s main-peak triangulation marker, I took advantage of a rare day of good weather to go check it out. The main route for this Qixing Mountain hike was from the Xiaoyoukeng trailhead -> Qixing Mountain main peak -> Qixing Mountain east peak, then back the same way to the Xiaoyoukeng parking lot. Qixing Mountain is the highest mountain within Taipei City, reaching an elevation of 1120 meters. Xiaoyouke...

IntroductionWhat is Fleet Provisioning?Fleet Provisioning can be divided into Provisioning by Claim and Provisioning by Trusted User. Provisioning by ClaimDevices can use embedded provisioning claim certificates (special-purpose certificates) and private keys for manufacturing. If these certificates are registered with AWS IoT, the service can exchange them for a unique device certificate that the device can use for general operations. Provisioning by Trusted UserIn many cases, when trusted u...

Intro - What is AWS IoT Device Shadow?In real world, sometime it is difficult to get the actual device state in real time in such IoT scenarios. A device shadow can overcome this challenge, Device Shadow can consider a virtual virtual representation of a device which managed by the IoT Things resource created in AWS IoT Core. The Shadow document is a JSON or a JavaScript notation doc that is used to store and retrieve the current state information for a device. You can use the shadow to get...

IntroductionAmazon SNS offen works well with Amazon SQS, by subscribing SQS to SNS, the SNS service can push messages to SQS. This may eliminating the need to periodically check or “poll” for updates. What is Amazon SQS?By official definition Amazon SQS is a message queue service used by distributed applications to exchange messages through a polling model, and can be used to decouple sending and receiving components—without requiring each component to be concurrently available. Scenario T...

What is S3 Gateway Endpoints? Let’s consider a scenario How could your Lambda function access the content in the S3 bucket? If you want a service to access the content in the S3 bucket, it usually go through VPC endpoint. S3 supports two types of VPC endpoint,each of which is Gateway endpoint and Interface endpoint The diffeences between two types of VPC endpoints are listed below S3 Gateway Endpoints S3 Interface Endpoints Use S3 Public IP Address Use Private IP Address in VPC to a...

🌐 中文版：繁體中文 PrefaceWhen configuring Lambda, the vast majority of people have hit ImportModuleError. So you can follow the scenario below, spin up the same Lambda environment, and work through it step by step. Scenario Region: IAD(us-east-1) Runtime: Python3.11 Lambda Name: “ITHomeLambdaFunction” Lambda code1234567891011import json requestsdef lambda_handler(event, context): # TODO implement x = requests.get('https://www.ntust.edu.tw/') print(x.text) return { ...

🌐 中文版：繁體中文 RecapEarlier I covered a basic intro to Lambda, Lambda runtimes, permission configuration, and observing initialization time and function execution time from the logs. At the end I left one question: What happens if we use the AWS CLI to invoke the function, opening three terminal tabs to invoke our Lambda at the same time? Experiment 1: setting Reserved ConcurrencyWe run this command: 12345aws lambda invoke \ --function-name TestInvocations \ --cli-binary-format raw-in-...

🌐 中文版：繁體中文 PrefaceFirst off, why does serverless always come up alongside Lambda? Let me introduce this service. FaaS (Function as a Service)Once you talk about serverless computing, its core concept comes up: Function as a Service (FaaS). Here’s Wikipedia’s explanation of FaaS: FaaS is a cloud computing model. Built on Platform as a Service (PaaS), serverless computing provides a micro-architecture where the end customer doesn’t need to deploy, configure, or manage server services; the s...

🌐 中文版：繁體中文 PrefaceIn today’s business environment, providing high-quality, efficient customer service is one of the keys to success. Amazon Connect is a powerful cloud contact center that helps businesses easily build highly reliable contact centers and interact seamlessly with customers. This post will walk you step by step through integrating a Lambda function into Amazon Connect to achieve more custom functionality. We’ll follow these steps to do the integration: Step 1: Create a Connec...

🌐 中文版：繁體中文 PrefaceThis is another problem I ran into while solving a case, but I’d never actually configured retries on Lambda, so in the spirit of experimentation I tried it out in my own environment. Error retries in Lambda are usually for re-sending an invocation request after an asynchronous invocation fails. For asynchronous invocations, Lambda places the event in a queue and returns a success response containing no other information. A separate process reads events from the queue and...