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AWS Global Infrastructure The AWS Global infrastructure is built around Regions and Availability Zones (AZs). So far, there are: 65+ Availability Zones 22 Geographic Regions 1 Local Region AWS Regions and Availability Zones. Source: AWS Regions provide multiple, physically separated and isolated Availability Zones which are connected with low latency, high throughput, and highly redundant networking. Availability Zones offer highly availability, fault tolerance, and scalability. Consist of one or more discrete data centers, each with redundant power, networking, and connectivity, housed in separate facilities. An Availability Zone is represented by a region code followed by a letter identifier; for example, [...]

How to invalidate API Gateway Cache To invalidate an existing cache entry of a request and retrieve the latest data from the integration endpoint, one must send the request together with the Cache-Control: max-age=0 header. If the recipient is authorized to communicate directly to the integration endpoint, then the integration endpoint will respond with the latest data for the request. This also replaces the existing cache entry with the new response. The IAM Policy that grants a client to invalidate the cache follows: {   "Version": "2012-10-17",   "Statement": [     {       "Effect": "Allow",       "Action": [         "execute-api:InvalidateCache"       ],       "Resource": [ "arn:aws:execute-api:region:account-id:api-id/stage-name/GET/resource-path-specifier"       ]     } [...]

Instrumenting your Application with AWS X-Ray Instrumenting your Node.js application The AWS X-Ray SDK for Node.js provides middleware that you can use to instrument incoming HTTP requests. You need to add the SDK to your application’s dependencies, usually via package.json. Initialize the SDK client and add it to your application prior to declaring routes. var AWSXRay = require('aws-xray-sdk'); AWSXRay.setDaemonAddress('host:port'); app.use(AWSXRay.express.openSegment('MyApp'));       3. Lastly, use the SDK exceptions after declaring routes. app.get('/', function (req, res) {   res.render('index'); }); app.use(AWSXRay.express.closeSegment()); Instrumenting your Java application The AWS X-Ray SDK for Java provides a servlet filter that you can add to your [...]

Calculating the Required Read and Write Capacity Unit for your DynamoDB Table Read Capacity Unit On-Demand Mode When you choose on-demand mode, DynamoDB instantly accommodates your workloads as they ramp up or down to any previously reached traffic level. If a workload’s traffic level hits a new peak, DynamoDB adapts rapidly to accommodate the workload. The request rate is only limited by the DynamoDB throughput default table limits, but it can be raised upon request. For on-demand mode tables, you don't need to specify how much read throughput you expect your application to perform. DynamoDB charges you for the reads [...]

AWS Lambda Integration with Amazon DynamoDB Streams Amazon DynamoDB is integrated with AWS Lambda so that you can create triggers, which are pieces of code that automatically respond to events in DynamoDB Streams. With triggers, you can build applications that react to data modifications in DynamoDB tables. After you enable DynamoDB Streams on a table, associate the DynamoDB table with a Lambda function. AWS Lambda polls the stream and invokes your Lambda function synchronously when it detects new stream records.  Configure the StreamSpecification you want for your DynamoDB Streams: StreamEnabled (Boolean) - indicates whether DynamoDB Streams is enabled (true) or [...]