This document provides a comprehensive analysis of the differences between Hadoop's original S3 and S3A (S3Advanced) filesystem implementations based on direct examination of the Hadoop codebase.

• Location: ~/hadoop/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3native/

This document explains the key differences when writing files with s3:// vs s3a:// prefixes in Apache Flink, focusing on the Hadoop and Presto S3 connectors.

• s3a://: Only registered by Hadoop S3A (via S3AFileSystemFactory)

1. Overview
2. TypeInformation: The Foundation
3. TypeSerializer: The Workhorse
4. The Complete Flow
5. Detailed Example Walkthrough
6. State Evolution and Migration
7. Architecture Insights

• Tokens must be tracked per service, only updated tokens must be sent to task managers
• Dynamic token initialization from user code must be added

  package org.apache.flink.api.common.security;

  /**
   * Manager for obtaining delegation tokens dynamically at runtime.
   * This allows user code to request tokens for services not known at cluster startup.

$ gpg --version
gpg (GnuPG) 2.4.8

Simple hanging!

from itertools import product

def generate_paintings():
    colors = ['A', 'B', 'C', 'D']
    hexagons = ['H1', 'H2', 'H3', 'H4', 'H5', 'H6', 'H7']  # 1 in the middle, 6 around
    
    # Generate all possible combinations of colors for the hexagons
    all_paintings = product(colors, repeat=7)
    

Python is not able to handle 2 different versions from the same package.

When Pip <20.3 finds an unresolvable dependency (resolves a dependecy to 2+ versions) then would not halt the installation process. It’d successfully continue the process by installing the first matching dependency in the list of conflicts.

    @SuppressWarnings("unchecked")
    public static void setEnv(String key, String value) {
        try {
            Map<String, String> env = System.getenv();
            Class<?> cl = env.getClass();
            Field field = cl.getDeclaredField("m");
            field.setAccessible(true);
            Map<String, String> writableEnv = (Map<String, String>) field.get(env);
 writableEnv.put(key, value);

Note1: types are java compatible
Note2: all strings are in UTF format

• short length
• byte [length]

• Deploy Flink k8s operator
• Install cmctl

$ kubectl get cert       
NAME                          READY   SECRET                AGE
flink-operator-serving-cert   True    webhook-server-cert   91m