使用 AWS API Gateway 整合 Lambda

以下是我的 Lambda code，他會取得網址的 name 參數值，並組成 "Hello World~"+name參數值的字串

def lambda_handler(event, context):
    # 從事件對象的 queryStringParameters 中獲取 "name" 參數
    name = event.get('queryStringParameters', {}).get('name', 'World')
    
    # 拼接字符串並返回結果
    return {
        'statusCode': 200,
        'headers': {
            'Content-Type': 'application/json'
        },
        'body': f'Hello World~{name}'
    }

以下是 API Gateway 的設定

1. 在 Create API 選擇 HTTP API => Click Build

2. 指定欲整合的 Lambda function name 與 API name

3. 指定 http method 與 resource path

4. 指定 stage name

5. 在 review page click Create button

Postman 測試畫面

1. 在 Stages 頁面取得 http url

2. 使用以下網址到 Postman 驗證結果

https://vo6ltr8xrl.execute-api.us-east-1.amazonaws.com/dev/hello?name=Mandy

執行 AWS PutMetricData operation 出現錯誤：The parameter MetricData.member.1.Timestamp must specify a time no more than two hours in the future

Problem

AWS PutMetricData operation 內容如下

#!/bin/bash
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:05:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:06:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:07:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:08:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:09:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:10:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:11:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:12:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:13:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:14:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:15:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:16:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:17:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:18:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:19:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:20:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T11:21:00.000Z

執行後出現以下錯誤

An error occurred (InvalidParameterValue) when calling the PutMetricData operation: The parameter MetricData.member.1.Timestamp must specify a time no more than two hours in the future.

An error occurred (InvalidParameterValue) when calling the PutMetricData operation: The parameter MetricData.member.1.Timestamp must specify a time no more than two hours in the future.

An error occurred (InvalidParameterValue) when calling the PutMetricData operation: The parameter MetricData.member.1.Timestamp must specify a time no more than two hours in the future.

An error occurred (InvalidParameterValue) when calling the PutMetricData operation: The parameter MetricData.member.1.Timestamp must specify a time no more than two hours in the future.

Root Cause

設定的 timestamp 時間不能比當前時間超過 2小時，此限制是為了防止因時間錯誤設置而導致數據不一致。

How-To

重新修正 timestamp

#!/bin/bash
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:05:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:06:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:07:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:08:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:09:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:10:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:11:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:12:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:13:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:14:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:15:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:16:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:17:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:18:00.000Z 
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:19:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:20:00.000Z
aws cloudwatch put-metric-data --metric-name CriticalError --namespace MyService --value 1 --timestamp 2024-02-09T03:21:00.000Z

在 CloudWatch Metrics 也如預期找到所執行的結果

AWS CloudWatch log group 未如預期出現所設定的 log group name

Problem

安裝 CloudWatch Agent 至 EC2，並將設定的 metrics 資料傳送至AWS CloudWatch log group，但在畫面未能找到所指定的 log group name。

config.json 的內容如下

{
        "agent": {
                "metrics_collection_interval": 1,
                "run_as_user": "cwagent"
        },
        "logs": {
                "logs_collected": {
                        "files": {
                                "collect_list": [
                                        {
                                                "file_path": "/var/log/messages",
                                                "log_group_class": "STANDARD",
                                                "log_group_name": "messages",
                                                "log_stream_name": "{instance_id}",
                                                "retention_in_days": 1
                                        }
                                ]
                        }
                }
        },
        "metrics": {
                "aggregation_dimensions": [
                        [
                                "InstanceId"
                        ]
                ],
                "append_dimensions": {
                        "AutoScalingGroupName": "${aws:AutoScalingGroupName}",
                        "ImageId": "${aws:ImageId}",
                        "InstanceId": "${aws:InstanceId}",
                        "InstanceType": "${aws:InstanceType}"
                },
                "metrics_collected": {
                        "cpu": {
                                "measurement": [
                                        "cpu_usage_idle",
                                        "cpu_usage_iowait",
                                        "cpu_usage_user",
                                        "cpu_usage_system"
                                ],
                                "metrics_collection_interval": 1,
                                "resources": [
                                        "*"
                                ],
                                "totalcpu": false
                        },
                        "disk": {
                                "measurement": [
                                        "used_percent",
                                        "inodes_free"
                                ],
                                "metrics_collection_interval": 1,
                                "resources": [
                                        "*"
                                ]
                        },
                        "diskio": {
                                "measurement": [
                                        "io_time"
                                ],
                                "metrics_collection_interval": 1,
                                "resources": [
                                        "*"
                                ]
                        },
                        "mem": {
                                "measurement": [
                                        "mem_used_percent"
                                ],
                                "metrics_collection_interval": 1
                        },
                        "statsd": {
                                "metrics_aggregation_interval": 10,
                                "metrics_collection_interval": 10,
                                "service_address": ":8125"
                        },
                        "swap": {
                                "measurement": [
                                        "swap_used_percent"
                                ],
                                "metrics_collection_interval": 1
                        }
                }
        }
}

Root Cause

到此目錄 /opt/aws/amazon-cloudwatch-agent/logs/ 檢查 CloudWatch Agent Log，發現是權限問題，我應該要把 run_as_user 改成 root

[inputs.logfile] Failed to tail file /var/log/messages with error: open /var/log/messages: permission denied

How-To

將 config.json 修改如下即可

{
        "agent": {
                "metrics_collection_interval": 1,
                "run_as_user": "root"
        },
        "logs": {
                "logs_collected": {
                        "files": {
                                "collect_list": [
                                        {
                                                "file_path": "/var/log/messages",
                                                "log_group_class": "STANDARD",
                                                "log_group_name": "messages",
                                                "log_stream_name": "{instance_id}",
                                                "retention_in_days": 1
                                        }
                                ]
                        }
                }
        },
        "metrics": {
                "aggregation_dimensions": [
                        [
                                "InstanceId"
                        ]
                ],
                "append_dimensions": {
                        "AutoScalingGroupName": "${aws:AutoScalingGroupName}",
                        "ImageId": "${aws:ImageId}",
                        "InstanceId": "${aws:InstanceId}",
                        "InstanceType": "${aws:InstanceType}"
                },
                "metrics_collected": {
                        "cpu": {
                                "measurement": [
                                        "cpu_usage_idle",
                                        "cpu_usage_iowait",
                                        "cpu_usage_user",
                                        "cpu_usage_system"
                                ],
                                "metrics_collection_interval": 1,
                                "resources": [
                                        "*"
                                ],
                                "totalcpu": false
                        },
                        "disk": {
                                "measurement": [
                                        "used_percent",
                                        "inodes_free"
                                ],
                                "metrics_collection_interval": 1,
                                "resources": [
                                        "*"
                                ]
                        },
                        "diskio": {
                                "measurement": [
                                        "io_time"
                                ],
                                "metrics_collection_interval": 1,
                                "resources": [
                                        "*"
                                ]
                        },
                        "mem": {
                                "measurement": [
                                        "mem_used_percent"
                                ],
                                "metrics_collection_interval": 1
                        },
                        "statsd": {
                                "metrics_aggregation_interval": 10,
                                "metrics_collection_interval": 10,
                                "service_address": ":8125"
                        },
                        "swap": {
                                "measurement": [
                                        "swap_used_percent"
                                ],
                                "metrics_collection_interval": 1
                        }
                }
        }
}

如何透過 AWS Lambda 呼叫 SES (Simple Email Service) 發信

實作步驟如下

1. 建立 Verified Identities來做為測試用途的 Sender 與 Receiver email address

2. 建立 Lambda Function 後，進入 Configuration => Permission，確認該 Role 具備 SES 角色權限

3. 呼叫 SES 的 Python code

import boto3
from botocore.exceptions import ClientError

def lambda_handler(event, context):
    # 建立 SES 客戶端
    ses_client = boto3.client('ses', region_name='us-east-1')  # 請根據需要替換為您的 SES 區域

    # 電子郵件參數
    SENDER = "hekarey795@giratex.com"  # 替換為您的發件人地址
    RECIPIENT = "hekarey795@giratex.com"  # 替換為您的收件人地址
    SUBJECT = "AWS SES Test Email from Lambda"
    BODY_TEXT = ("This is a test email sent from AWS Lambda using SES")
    CHARSET = "UTF-8"

    # 嘗試發送電子郵件
    try:
        response = ses_client.send_email(
            Destination={
                'ToAddresses': [
                    RECIPIENT,
                ],
            },
            Message={
                'Body': {
                    'Text': {
                        'Charset': CHARSET,
                        'Data': BODY_TEXT,
                    },
                },
                'Subject': {
                    'Charset': CHARSET,
                    'Data': SUBJECT,
                },
            },
            Source=SENDER,
        )
    except ClientError as e:
        print(e.response['Error']['Message'])
    else:
        print("Email sent! Message ID:"),
        print(response['MessageId'])

4. 執行結果

5. 檢查信箱

透過 AWS EC2 Connect 連入編輯檔案，出現 "index.html" E212: Can't open file for writing 錯誤

Problem

透過 AWS EC2 Connect 連入編輯檔案，出現 "index.html" E212: Can't open file for writing 錯誤

Root Cause

會出現上述問題是因為權限不足所導致

How-To

[ec2-user@ip-172-31-43-197 html]$ vi index.html 
[ec2-user@ip-172-31-43-197 html]$ sudo vi index.html

AWS CloudShell 無法成功執行指令

Problem

我在 CloudShell 執行以下指令，卻無法正常執行

aws cognito-identity set-identity-pool-roles \
--identity-pool-id "us-east-1:xxxx-xxxx-xxxx-xxxx-xxxxxx” \
--roles unauthenticated=arn:aws:iam::xxxx:role/Cognito_DynamoPoolUnauth --output json

Root Cause

第二行的第二個 double quote 有打錯

aws cognito-identity set-identity-pool-roles \
--identity-pool-id "us-east-1:xxxx-xxxx-xxxx-xxxx-xxxxxx” \
--roles unauthenticated=arn:aws:iam::xxxx:role/Cognito_DynamoPoolUnauth --output json

How-To

修正為正確的 double quote 後即可正常執行

aws cognito-identity set-identity-pool-roles \
--identity-pool-id "us-east-1:xxxx-xxxx-xxxx-xxxx-xxxxxx" \
--roles unauthenticated=arn:aws:iam::xxxx:role/Cognito_DynamoPoolUnauth --output json

AWS CloudFormation Error: TemplateURL must be a supported URL

Problem

當我要執行以下 CloudFormation yaml file:

{
    "AWSTemplateFormatVersion" : "2010-09-09",
    "Resources" : {
        "myStack" : {
	       "Type" : "AWS::CloudFormation::Stack",
	       "Properties" : {
              "TemplateURL" : "https://s3.amazonaws.com/nested-demo-531193295833/s3static.json",
              "TimeoutInMinutes" : "60"
	       }
        },
        "myStack2" : {
            "Type" : "AWS::CloudFormation::Stack",
            "Properties" : {
               "TemplateURL" : "https://s3.amazonaws.com/nested-demo-531193295833/noretain.json",
               "TimeoutInMinutes" : "60"
            }
         }    
    }
}

出現以下錯誤

Root Cause

因為 TemplateURL 輸入有誤，故出現上述錯誤

{
    "AWSTemplateFormatVersion" : "2010-09-09",
    "Resources" : {
        "myStack" : {
	       "Type" : "AWS::CloudFormation::Stack",
	       "Properties" : {
              "TemplateURL" : "https://s3.amazonaws.com/nested-demo-531193295833/s3static.json",
              "TimeoutInMinutes" : "60"
	       }
        },
        "myStack2" : {
            "Type" : "AWS::CloudFormation::Stack",
            "Properties" : {
               "TemplateURL" : "https://s3.amazonaws.com/nested-demo-531193295833/noretain.json",
               "TimeoutInMinutes" : "60"
            }
         }    
    }
}

How-To

重新修正 YAML 內容中的 TemplateURL，即可成功執行

{
    "AWSTemplateFormatVersion" : "2010-09-09",
    "Resources" : {
        "myStack" : {
	       "Type" : "AWS::CloudFormation::Stack",
	       "Properties" : {
              "TemplateURL" : "https://nested-demo-531193295833.s3.amazonaws.com/s3static.json",
              "TimeoutInMinutes" : "60"
	       }
        },
        "myStack2" : {
            "Type" : "AWS::CloudFormation::Stack",
            "Properties" : {
               "TemplateURL" : "https://nested-demo-531193295833.s3.amazonaws.com/noretain.json",
               "TimeoutInMinutes" : "60"
            }
         }    
    }
}

執行結果

AWS CloudFormation Error Code: InvalidAMIID.NotFound

Problem

當我透過已經編輯好的 CloudFormation yaml file 來建立相關資源，出現以下錯誤訊息

Root Cause

因為 yaml file 中的 image id 在該 region 不存在，所以會出現上述錯誤

How-To

Fix image id 即可成功建立資源

AWSTemplateFormatVersion: 2010-09-09

Description: Template to create an EC2 instance and enable SSH

Parameters: 
  KeyName:
    Description: Name of SSH KeyPair
    Type: 'AWS::EC2::KeyPair::KeyName'
    ConstraintDescription: Provide the name of an existing SSH key pair

Resources:
  MyEC2Instance:
    Type: 'AWS::EC2::Instance'
    Properties:
      InstanceType: t2.micro
      ImageId: ami-0277155c3f0ab2930
      KeyName: !Ref KeyName
      SecurityGroups:
       - Ref: InstanceSecurityGroup
      Tags:
        - Key: Name
          Value: My CF Instance
  InstanceSecurityGroup:
    Type: 'AWS::EC2::SecurityGroup'
    Properties:
      GroupDescription: Enable SSH access via port 22
      SecurityGroupIngress:
        IpProtocol: tcp
        FromPort: 22
        ToPort: 22
        CidrIp: 0.0.0.0/0

Outputs: 
  InstanceID:
    Description: The Instance ID
    Value: !Ref MyEC2Instance

AWS CloudFormation 建立失敗：The key pair 'irkp' does not exist (Service: AmazonEC2; Status Code: 400; Error Code: InvalidKeyPair.NotFound

Problem

當我透過 CLI 建立相關 AWS 資源

aws cloudformation create-stack --stack-name CodeDeployDemoStack-2 \
--template-url https://my-cf-template-347854199521.s3.amazonaws.com/CF_Template.json \
--parameters ParameterKey=InstanceCount,ParameterValue=1 \
ParameterKey=InstanceType,ParameterValue=t3.micro \
ParameterKey=KeyPairName,ParameterValue=irkp \
ParameterKey=OperatingSystem,ParameterValue=Linux \
ParameterKey=SSHLocation,ParameterValue=0.0.0.0/0 \
ParameterKey=TagKey,ParameterValue=Name \
ParameterKey=TagValue,ParameterValue=CodeDeployDemo \
--capabilities CAPABILITY_IAM

出現以下錯誤

Root Cause

因為指令列中的 key pair 不存在

How-To

修正 AWS CLI 為存在的的 key pair 名字

aws cloudformation create-stack --stack-name CodeDeployDemoStack-3 \
--template-url https://my-cf-template-347854199521.s3.amazonaws.com/CF_Template.json \
--parameters ParameterKey=InstanceCount,ParameterValue=1 \
ParameterKey=InstanceType,ParameterValue=t3.micro \
ParameterKey=KeyPairName,ParameterValue=nvkp \
ParameterKey=OperatingSystem,ParameterValue=Linux \
ParameterKey=SSHLocation,ParameterValue=0.0.0.0/0 \
ParameterKey=TagKey,ParameterValue=Name \
ParameterKey=TagValue,ParameterValue=CodeDeployDemo \
--capabilities CAPABILITY_IAM

執行結果

AWS CodeDploy 失敗：Zip end of central directory signature not found

Problem

我已經 upload source code 到指定 S3 bucket，並規劃透過 CodeDploy 從 S3 bucket 上傳 source code 到指定的 EC2 instances，但發生錯誤

Root Cause

經查 Deployment lifecycle events，發現是在 DownloadBundle 時發生錯誤

錯誤訊息為：Zip end of central directory signature not found

此錯誤訊息的成因：

在 AWS CodeDeploy 的過程中，試圖從 S3 下載並解壓 ZIP 壓縮檔作為部署包時，無法正確解壓縮檔案，此錯誤通常為檔案毀損。

Solution

重新上傳 source code 至 S3，即可成功透過 CodeDepoly 佈署程式

"errorMessage": "require is not defined in ES module scope, you can use import instead"

Problem

我在跟著 cloudguru 的 lab，學習如何寫一個簡單的 Node.js Lambda function

const https = require('https');
let url = "https://www.amazon.com";

exports.handler = async function(event) {
    let statusCode;
    await new Promise(function(resolve, reject) {
        https.get(url, (res) => {
            statusCode = res.statusCode;
            resolve(statusCode);
        }).on("error", (e) => {
            reject(Error(e));
        });
    });
    console.log(statusCode);
    return statusCode;
};

執行 Test Event 出現以下錯誤訊息

Test Event Name
MyTestEvent

Response
{
  "errorType": "ReferenceError",
  "errorMessage": "require is not defined in ES module scope, you can use import instead",
  "trace": [
    "ReferenceError: require is not defined in ES module scope, you can use import instead",
    "    at file:///var/task/index.mjs:1:15",
    "    at ModuleJob.run (node:internal/modules/esm/module_job:218:25)",
    "    at async ModuleLoader.import (node:internal/modules/esm/loader:329:24)",
    "    at async _tryAwaitImport (file:///var/runtime/index.mjs:1008:16)",
    "    at async _tryRequire (file:///var/runtime/index.mjs:1057:86)",
    "    at async _loadUserApp (file:///var/runtime/index.mjs:1081:16)",
    "    at async UserFunction.js.module.exports.load (file:///var/runtime/index.mjs:1119:21)",
    "    at async start (file:///var/runtime/index.mjs:1282:23)",
    "    at async file:///var/runtime/index.mjs:1288:1"
  ]
}

Root Cause

當您在 AWS Lambda 中使用 Node.js 20 版本，並且選擇使用 .mjs 附檔名時，Lambda 函數被視為 ES module。在 ECMAScript module 中，標準的 require 語法不能使用，因為它是 CommonJS 模塊系統的一部分，連帶上述 export 語法也需稍微改寫

Solution

程式碼需修改如下

import https from 'https';
let url = "https://www.amazon.com";

export async function handler(event) {
    let statusCode;
    await new Promise(function(resolve, reject) {
        https.get(url, (res) => {
            statusCode = res.statusCode;
            resolve(statusCode);
        }).on("error", (e) => {
            reject(Error(e));
        });
    });
    console.log(statusCode);
    return statusCode;
};

執行結果

Unable to install mysqlclient package on EC2 instance (Amazon Linux 2023)

Problem

當我在建立 EC2 instance 時，輸入以下 bootstrap script 至 user data

#!/bin/bash yum update -y yum install mysql -y

但是當啟動 EC2 後，使用 EC2 Instance Connect 進入後，輸入 mysql --version 卻出現以下錯誤訊息

mysql: command not found

經查啟動 log，發現 mysql client 安裝失敗

[ec2-user@ip-172-31-44-29 ~]$ cat /var/log/cloud-init-output.log
Last metadata expiration check: 0:00:03 ago on Mon Jan  1 04:21:12 2024.
No match for argument: mysql
Error: Unable to find a match: mysql
2024-01-01 04:21:15,423 - cc_scripts_user.py[WARNING]: Failed to run module scripts-user (scripts in /var/lib/cloud/instance/scripts)
2024-01-01 04:21:15,424 - util.py[WARNING]: Running module scripts-user (<module 'cloudinit.config.cc_scripts_user' from '/usr/lib/python3.9/site-packages/cloudinit/config/cc_scripts_user.py'>) failed
Cloud-init v. 22.2.2 finished at Mon, 01 Jan 2024 04:21:15 +0000. Datasource DataSourceEc2.  Up 32.23 seconds

Solution

經查因 Amazon Linux 2023 的內建套件與過往的 AMI 不同，需執行以下指令

# install pip (AL 2023 does not have one by default)
sudo dnf install -y pip

# install dependencies
sudo dnf install -y mariadb105-devel gcc python3-devel

# install mysqlclient
pip install mysqlclient

執行結果

   ,     #_
   ~\_  ####_        Amazon Linux 2023
  ~~  \_#####\
  ~~     \###|
  ~~       \#/ ___   https://aws.amazon.com/linux/amazon-linux-2023
   ~~       V~' '->
    ~~~         /
      ~~._.   _/
         _/ _/
       _/m/'
Last login: Mon Jan  1 04:24:46 2024 from 18.206.107.28
[ec2-user@ip-172-31-44-29 ~]$ mysql --version
mysql  Ver 8.0.35 for Linux on x86_64 (MySQL Community Server - GPL)

Increase/Decrease Font Size in iTerm2

Problem 

How to Increase/Decrease Font Size in iTerm2

How To

View => Make Text Bigger

AWS IAM policy simulator

AWS IAM (Identity and Access Management) Policy Simulator from Guo Albert

AWS S3 Durability and Availability

AWS S3 Durability （耐久性）

• 任何 S3 storage class 皆相同
• S3 的 durability 為 99.999999999% ，假設你存放  10,000,000 個檔案，每 10,000 年才會有一個檔案遺失。計算公式如下
• average annual expected loss % = 100 - 99.99999999999 = 0.00000000001 
• 損失一個檔案所需時間 = 10,000,000 * 10,000 * 0.00000000001 = 1.000444172

AWS S3 Availability （可用性）

• 不同的 S3 storage class 有所差異
• 以 S3 Standard 來說，Availability = 99.99%，代表一年只有 53 分鐘無法使用，計算公式如下
• 一年的分鐘數 = 365 * 24 * 60 = 525,600 分鐘
• non-availability = 1 - 0.9999 = 0.0001
• 一年無法使用的分鐘數 = 525,600 * 0.0001 = 52.56 分鐘