index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
<meta name="viewport" content="width=device-width">
<meta name="theme-color" content="#222"><meta name="generator" content="Hexo 6.3.0">

  <link rel="apple-touch-icon" sizes="180x180" href="/images/apple-touch-icon-next.png">
  <link rel="icon" type="image/png" sizes="32x32" href="/images/favicon-32x32-next.png">
  <link rel="icon" type="image/png" sizes="16x16" href="/images/favicon-16x16-next.png">
  <link rel="mask-icon" href="/images/logo.svg" color="#222">

<link rel="stylesheet" href="/css/main.css">


<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.2.1/css/all.min.css" integrity="sha256-Z1K5uhUaJXA7Ll0XrZ/0JhX4lAtZFpT6jkKrEDT0drU=" crossorigin="anonymous">
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.1.1/animate.min.css" integrity="sha256-PR7ttpcvz8qrF57fur/yAx1qXMFJeJFiA6pSzWi0OIE=" crossorigin="anonymous">

<script class="next-config" data-name="main" type="application/json">{"hostname":"liam-blog.ml","root":"/","images":"/images","scheme":"Gemini","darkmode":false,"version":"8.14.0","exturl":false,"sidebar":{"position":"left","display":"post","padding":18,"offset":12},"copycode":{"enable":true,"style":null},"bookmark":{"enable":false,"color":"#222","save":"auto"},"mediumzoom":false,"lazyload":false,"pangu":false,"comments":{"style":"tabs","active":null,"storage":true,"lazyload":false,"nav":null},"stickytabs":false,"motion":{"enable":true,"async":false,"transition":{"menu_item":"fadeInDown","post_block":"fadeIn","post_header":"fadeInDown","post_body":"fadeInDown","coll_header":"fadeInLeft","sidebar":"fadeInUp"}},"prism":false,"i18n":{"placeholder":"Searching...","empty":"We didn't find any results for the search: ${query}","hits_time":"${hits} results found in ${time} ms","hits":"${hits} results found"},"path":"/search.xml","localsearch":{"enable":true,"trigger":"auto","top_n_per_article":1,"unescape":false,"preload":false}}</script><script src="/js/config.js"></script>

    <meta property="og:type" content="website">
<meta property="og:title" content="Liam&#39;s Blog">
<meta property="og:url" content="https://liam-blog.ml/index.html">
<meta property="og:site_name" content="Liam&#39;s Blog">
<meta property="og:locale" content="en_US">
<meta property="article:author" content="Liam">
<meta name="twitter:card" content="summary">


<link rel="canonical" href="https://liam-blog.ml/">


<script class="next-config" data-name="page" type="application/json">{"sidebar":"","isHome":true,"isPost":false,"lang":"en","comments":"","permalink":"","path":"index.html","title":""}</script>

<script class="next-config" data-name="calendar" type="application/json">""</script>
<title>Liam's Blog</title>
  
    <script async src="https://www.googletagmanager.com/gtag/js?id=G-3LJ1Y8TCD3"></script>
  <script class="next-config" data-name="google_analytics" type="application/json">{"tracking_id":"G-3LJ1Y8TCD3","only_pageview":false}</script>
  <script src="/js/third-party/analytics/google-analytics.js"></script>


  <script async defer data-website-id="" src=""></script>

  <script defer data-domain="" src=""></script>

  <noscript>
    <link rel="stylesheet" href="/css/noscript.css">
  </noscript>
<link rel="alternate" href="/atom.xml" title="Liam's Blog" type="application/atom+xml">
</head>

<body itemscope itemtype="http://schema.org/WebPage" class="use-motion">
  <div class="headband"></div>

  <main class="main">
    <div class="column">
      <header class="header" itemscope itemtype="http://schema.org/WPHeader"><div class="site-brand-container">
  <div class="site-nav-toggle">
    <div class="toggle" aria-label="Toggle navigation bar" role="button">
        <span class="toggle-line"></span>
        <span class="toggle-line"></span>
        <span class="toggle-line"></span>
    </div>
  </div>

  <div class="site-meta">

    <a href="/" class="brand" rel="start">
      <i class="logo-line"></i>
      <h1 class="site-title">Liam's Blog</h1>
      <i class="logo-line"></i>
    </a>
      <p class="site-subtitle" itemprop="description">Hi there, 2023!</p>
  </div>

  <div class="site-nav-right">
    <div class="toggle popup-trigger" aria-label="Search" role="button">
        <i class="fa fa-search fa-fw fa-lg"></i>
    </div>
  </div>
</div>


<nav class="site-nav">
  <ul class="main-menu menu"><li class="menu-item menu-item-home"><a href="/" rel="section"><i class="fa fa-home fa-fw"></i>Home</a></li><li class="menu-item menu-item-tags"><a href="/tags/" rel="section"><i class="fa fa-tags fa-fw"></i>Tags</a></li><li class="menu-item menu-item-archives"><a href="/archives/" rel="section"><i class="fa fa-archive fa-fw"></i>Archives</a></li><li class="menu-item menu-item-rss"><a href="/atom.xml" rel="section"><i class="fa fa-rss fa-fw"></i>RSS</a></li>
      <li class="menu-item menu-item-search">
        <a role="button" class="popup-trigger"><i class="fa fa-search fa-fw"></i>Search
        </a>
      </li>
  </ul>
</nav>


  <div class="search-pop-overlay">
    <div class="popup search-popup"><div class="search-header">
  <span class="search-icon">
    <i class="fa fa-search"></i>
  </span>
  <div class="search-input-container">
    <input autocomplete="off" autocapitalize="off" maxlength="80"
           placeholder="Searching..." spellcheck="false"
           type="search" class="search-input">
  </div>
  <span class="popup-btn-close" role="button">
    <i class="fa fa-times-circle"></i>
  </span>
</div>
<div class="search-result-container no-result">
  <div class="search-result-icon">
    <i class="fa fa-spinner fa-pulse fa-5x"></i>
  </div>
</div>

    </div>
  </div>

</header>
        
  
  <aside class="sidebar">

    <div class="sidebar-inner sidebar-overview-active">
      <ul class="sidebar-nav">
        <li class="sidebar-nav-toc">
          Table of Contents
        </li>
        <li class="sidebar-nav-overview">
          Overview
        </li>
      </ul>

      <div class="sidebar-panel-container">
        <!--noindex-->
        <div class="post-toc-wrap sidebar-panel">
        </div>
        <!--/noindex-->

        <div class="site-overview-wrap sidebar-panel">
          <div class="site-author animated" itemprop="author" itemscope itemtype="http://schema.org/Person">
    <img class="site-author-image" itemprop="image" alt="Liam"
      src="/images/long-cat.jpeg">
  <p class="site-author-name" itemprop="name">Liam</p>
  <div class="site-description" itemprop="description"></div>
</div>
<div class="site-state-wrap animated">
  <nav class="site-state">
      <div class="site-state-item site-state-posts">
        <a href="/archives/">
          <span class="site-state-item-count">36</span>
          <span class="site-state-item-name">posts</span>
        </a>
      </div>
      <div class="site-state-item site-state-tags">
          <a href="/tags/">
        <span class="site-state-item-count">29</span>
        <span class="site-state-item-name">tags</span></a>
      </div>
  </nav>
</div>

        </div>
      </div>
    </div>

    
  </aside>


    </div>

    <div class="main-inner index posts-expand">

    
<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2022/04/25/Extend-Spark-Data-Source/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2022/04/25/Extend-Spark-Data-Source/" class="post-title-link" itemprop="url">Extend Spark Data Source with DataFrame</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2022-04-25 22:39:17" itemprop="dateCreated datePublished" datetime="2022-04-25T22:39:17+08:00">2022-04-25</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <p>In this article, we’ll implement a spark data source for reading and writing a Google spreadsheet, so that you’ll know how to extend the data source of Spark by yourself.</p>
<h2 id="What’s-a-customized-data-source-like"><a href="#What’s-a-customized-data-source-like" class="headerlink" title="What’s a customized data source like?"></a>What’s a customized data source like?</h2><h3 id="read-data-from-Google-Spreadsheet-into-a-DataFrame"><a href="#read-data-from-Google-Spreadsheet-into-a-DataFrame" class="headerlink" title="read data from Google Spreadsheet into a DataFrame"></a>read data from Google Spreadsheet into a DataFrame</h3><figure class="highlight scala"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">val</span> data = spark.read.format(<span class="string">&quot;google-spreadsheet&quot;</span>)</span><br><span class="line">  .option(<span class="string">&quot;credentialsPath&quot;</span>, credentialFile)</span><br><span class="line">  .option(<span class="string">&quot;spreadsheetId&quot;</span>, spreadsheetId)</span><br><span class="line">  .option(<span class="string">&quot;sheetName&quot;</span>, sheetName1)</span><br><span class="line">  .load()</span><br></pre></td></tr></table></figure>

<h3 id="write-data-of-a-DataFrame-into-Google-Spreadsheet"><a href="#write-data-of-a-DataFrame-into-Google-Spreadsheet" class="headerlink" title="write data of a DataFrame into Google Spreadsheet"></a>write data of a DataFrame into Google Spreadsheet</h3><figure class="highlight scala"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">df.write.format(<span class="string">&quot;google-spreadsheet&quot;</span>)</span><br><span class="line">  .option(<span class="string">&quot;credentialsPath&quot;</span>, credentialFile)</span><br><span class="line">  .option(<span class="string">&quot;spreadsheetId&quot;</span>, spreadsheetId)</span><br><span class="line">  .option(<span class="string">&quot;sheetName&quot;</span>, sheetName)</span><br><span class="line">  .mode(<span class="type">SaveMode</span>.<span class="type">Overwrite</span>)</span><br><span class="line">  .save()</span><br></pre></td></tr></table></figure>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2022/04/25/Extend-Spark-Data-Source/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2021/09/24/How-to-solve-dependency-conflicts-with-Maven/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2021/09/24/How-to-solve-dependency-conflicts-with-Maven/" class="post-title-link" itemprop="url">How to solve dependency conflicts with Maven</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2021-09-24 20:25:25" itemprop="dateCreated datePublished" datetime="2021-09-24T20:25:25+08:00">2021-09-24</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <h2 id="What-are-dependency-conflicts"><a href="#What-are-dependency-conflicts" class="headerlink" title="What are dependency conflicts?"></a>What are dependency conflicts?</h2><p>Here is an example, this project has 2 dependencies, and both of them depend on the Guava library with different versions.</p>
<figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">&lt;!-- Project dependencies --&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">dependencies</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">dependency</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">groupId</span>&gt;</span>org.example<span class="tag">&lt;/<span class="name">groupId</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">artifactId</span>&gt;</span>study-maven-2<span class="tag">&lt;/<span class="name">artifactId</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">version</span>&gt;</span>1.0-SNAPSHOT<span class="tag">&lt;/<span class="name">version</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">dependency</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">dependency</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">groupId</span>&gt;</span>org.example<span class="tag">&lt;/<span class="name">groupId</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">artifactId</span>&gt;</span>study-maven-3<span class="tag">&lt;/<span class="name">artifactId</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">version</span>&gt;</span>1.0-SNAPSHOT<span class="tag">&lt;/<span class="name">version</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">dependency</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;/<span class="name">dependencies</span>&gt;</span></span><br></pre></td></tr></table></figure>

<figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="tag">&lt;<span class="name">groupId</span>&gt;</span>org.example<span class="tag">&lt;/<span class="name">groupId</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">artifactId</span>&gt;</span>study-maven-2<span class="tag">&lt;/<span class="name">artifactId</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">version</span>&gt;</span>1.0-SNAPSHOT<span class="tag">&lt;/<span class="name">version</span>&gt;</span></span><br><span class="line"></span><br><span class="line">    <span class="tag">&lt;<span class="name">dependencies</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">dependency</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">groupId</span>&gt;</span>com.google.guava<span class="tag">&lt;/<span class="name">groupId</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">artifactId</span>&gt;</span>guava<span class="tag">&lt;/<span class="name">artifactId</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">version</span>&gt;</span>30.1.1-jre<span class="tag">&lt;/<span class="name">version</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">dependency</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;/<span class="name">dependencies</span>&gt;</span></span><br></pre></td></tr></table></figure>

<figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="tag">&lt;<span class="name">groupId</span>&gt;</span>org.example<span class="tag">&lt;/<span class="name">groupId</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">artifactId</span>&gt;</span>study-maven-3<span class="tag">&lt;/<span class="name">artifactId</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;<span class="name">version</span>&gt;</span>1.0-SNAPSHOT<span class="tag">&lt;/<span class="name">version</span>&gt;</span></span><br><span class="line"></span><br><span class="line">    <span class="tag">&lt;<span class="name">dependencies</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;<span class="name">dependency</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">groupId</span>&gt;</span>com.google.guava<span class="tag">&lt;/<span class="name">groupId</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">artifactId</span>&gt;</span>guava<span class="tag">&lt;/<span class="name">artifactId</span>&gt;</span></span><br><span class="line">            <span class="tag">&lt;<span class="name">version</span>&gt;</span>29.0-jre<span class="tag">&lt;/<span class="name">version</span>&gt;</span></span><br><span class="line">        <span class="tag">&lt;/<span class="name">dependency</span>&gt;</span></span><br><span class="line">    <span class="tag">&lt;/<span class="name">dependencies</span>&gt;</span></span><br></pre></td></tr></table></figure>

<p>As you all know, we can’t have two classes with the same package and name in one project. So there would be conflicts if different versions of a package are imported. Obviously, in this case, only one version of Guava will be imported.</p>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2021/09/24/How-to-solve-dependency-conflicts-with-Maven/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2021/05/08/Kafka-Fundamental-Concepts/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2021/05/08/Kafka-Fundamental-Concepts/" class="post-title-link" itemprop="url">Kafka Fundamental Concepts</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2021-05-08 17:16:13" itemprop="dateCreated datePublished" datetime="2021-05-08T17:16:13+08:00">2021-05-08</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <h1 id="What-is-Kafka"><a href="#What-is-Kafka" class="headerlink" title="What is Kafka?"></a>What is Kafka?</h1><blockquote>
<p><a target="_blank" rel="noopener" href="https://www.confluent.io/what-is-apache-kafka/">Apache Kafka</a> is an event streaming platform used to collect, process, store, and integrate data at scale. It has numerous use cases including distributed logging, stream processing, data integration, and pub&#x2F;sub messaging.</p>
</blockquote>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2021/05/08/Kafka-Fundamental-Concepts/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2020/05/31/details-you-need-to-know-about-Apache-Parquet/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2020/05/31/details-you-need-to-know-about-Apache-Parquet/" class="post-title-link" itemprop="url">Details you need to know about Apache Parquet</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2020-05-31 12:25:42" itemprop="dateCreated datePublished" datetime="2020-05-31T12:25:42+08:00">2020-05-31</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <p>Parquet is a columnar file format that supports nested data. Lots of data systems support this data format because of it’s great advantage of performance.</p>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2020/05/31/details-you-need-to-know-about-Apache-Parquet/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2020/03/29/redis-lock-rate-limiter/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2020/03/29/redis-lock-rate-limiter/" class="post-title-link" itemprop="url">基于Redis实现分布式锁和分布式限流器</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2020-03-29 12:37:12" itemprop="dateCreated datePublished" datetime="2020-03-29T12:37:12+08:00">2020-03-29</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <p>分布式锁和分布式限流器应该是算是比较常见的需求了，而Redis现在几乎是应用的标配了，于是很多人会倾向于选择基于Redis来实现，因为不需要引入额外的依赖。</p>
<p>分布式锁和分布式限流器在Java领域比较成熟和常用的开源实现是Redisson(<a target="_blank" rel="noopener" href="https://github.com/redisson/redisson/wiki/Redisson%E9%A1%B9%E7%9B%AE%E4%BB%8B%E7%BB%8D">中文官方介绍</a>)，下面从它的极小部分源码，分析下分布式锁和分布式限流器的实现逻辑。</p>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2020/03/29/redis-lock-rate-limiter/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2020/02/29/spark-core-memory/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2020/02/29/spark-core-memory/" class="post-title-link" itemprop="url">Spark Core 解析 4：内存模型</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2020-02-29 23:20:38" itemprop="dateCreated datePublished" datetime="2020-02-29T23:20:38+08:00">2020-02-29</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <h2 id="Spark内存模型"><a href="#Spark内存模型" class="headerlink" title="Spark内存模型"></a>Spark内存模型</h2><p>Spark之所以快，很大程度上是因为它善于利用内存，大量利用内存进行存储和计算，从而减少磁盘IO，提升执行效率。</p>
<p>从1.6版本开始，Spark引入了统一内存管理模型（之前版本只有静态内存管理，这里不细说），找到两张图描述的很清楚：</p>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2020/02/29/spark-core-memory/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2019/12/29/spark-core-shuffle/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2019/12/29/spark-core-shuffle/" class="post-title-link" itemprop="url">Spark Core 解析 3：Shuffle</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2019-12-29 11:42:44" itemprop="dateCreated datePublished" datetime="2019-12-29T11:42:44+08:00">2019-12-29</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <h2 id="Overview"><a href="#Overview" class="headerlink" title="Overview"></a>Overview</h2><p>所谓shuffle就是将数据按新的规则进行分区的过程，将数据分区从旧分区转变成新分区。</p>
<p><img src="https://raw.githubusercontent.com/Liam8/img/master/blog/20191229115009.png" alt="20191229115009.png"></p>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2019/12/29/spark-core-shuffle/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2019/11/07/spark-core-scheduler/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2019/11/07/spark-core-scheduler/" class="post-title-link" itemprop="url">Spark Core解析 2：Scheduler 调度体系</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2019-11-07 22:50:27" itemprop="dateCreated datePublished" datetime="2019-11-07T22:50:27+08:00">2019-11-07</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <h2 id="Overview"><a href="#Overview" class="headerlink" title="Overview"></a>Overview</h2><p>调度系统，是贯穿整个Spark应用的主心骨，从调度系统开始入手了解Spark Core，比较容易理清头绪。</p>
<p>Spark的资源调度采用的是常见的两层调度，底层资源的管理和分配是第一层调度，交给YARN、Mesos或者Spark的Standalone集群处理，Application从第一层调度拿到资源后，还要进行内部的任务和资源调度，将任务和资源进行匹配，这是第二层调度，<strong>本文讲的就是这第二层调度</strong>。</p>
<p>Spark的调度体系涉及的任务包括3个粒度，分别是Job、Stage、Task。<br>Job代表用户提交的一系列操作的总体，一个具体的计算任务，有明确的输入输出，一个Job由多个Stage组成；<br>一个Stage代表Job计算流程的一个组成部分，一个阶段，包含多个Task；<br>一个Task代表对一个分区的数据进行计算的具体任务。</p>
<p>层级关系：Job &gt; Stage &gt; Task</p>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2019/11/07/spark-core-scheduler/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2019/10/23/spark-core-rdd/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2019/10/23/spark-core-rdd/" class="post-title-link" itemprop="url">Spark Core解析 1：RDD 弹性分布式数据集</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2019-10-23 23:25:37" itemprop="dateCreated datePublished" datetime="2019-10-23T23:25:37+08:00">2019-10-23</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <h1 id="引言"><a href="#引言" class="headerlink" title="引言"></a>引言</h1><p>Spark Core是Spark的核心部分，是Spark SQL，Spark Streaming，Spark MLlib等等其他模块的基础, Spark Core提供了开发分布式应用的脚手架，使得其他模块或应用的开发者不必关心复杂的分布式计算如何实现，只需使用Spark Core提供的分布式数据结构RDD及丰富的算子API，以类似开发单机应用的方式来进行开发。</p>
<p><img src="https://raw.githubusercontent.com/Liam8/img/master/blog/spark.png" alt="spark.png"></p>
<p>图中最下面那个就是Spark Core啦，日常使用的RDD相关的API就属于Spark Core，而Dataset、DataFrame则属于Spark SQL。</p>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2019/10/23/spark-core-rdd/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


<div class="post-block">
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="">
    <link itemprop="mainEntityOfPage" href="https://liam-blog.ml/2019/09/28/scala-implicit/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/long-cat.jpeg">
      <meta itemprop="name" content="Liam">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Liam's Blog">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="undefined | Liam's Blog">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h2 class="post-title" itemprop="name headline">
          <a href="/2019/09/28/scala-implicit/" class="post-title-link" itemprop="url">Scala implicit 隐式转换安全驾驶指南</a>
        </h2>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">Posted on</span>

      <time title="Created: 2019-09-28 22:32:17" itemprop="dateCreated datePublished" datetime="2019-09-28T22:32:17+08:00">2019-09-28</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar-check"></i>
      </span>
      <span class="post-meta-item-text">Edited on</span>
      <time title="Modified: 2022-12-03 17:20:44" itemprop="dateModified" datetime="2022-12-03T17:20:44+08:00">2022-12-03</time>
    </span>

  
</div>

        </div>
      </header>

    
    <div class="post-body" itemprop="articleBody">
          <p>这篇短文将结合实例对隐式转换的各种场景进行解释和总结，希望看完的人能够安全驶过隐式转换这个大坑。</p>
          <!--noindex-->
            <div class="post-button">
              <a class="btn" href="/2019/09/28/scala-implicit/#more" rel="contents">
                Read more &raquo;
              </a>
            </div>
          <!--/noindex-->
        
      
    </div>

    
    <footer class="post-footer">
        <div class="post-eof"></div>
      
    </footer>
  </article>
</div>


  <nav class="pagination">
    <span class="page-number current">1</span><a class="page-number" href="/page/2/">2</a><span class="space">&hellip;</span><a class="page-number" href="/page/4/">4</a><a class="extend next" rel="next" title="Next page" aria-label="Next page" href="/page/2/"><i class="fa fa-angle-right"></i></a>
  </nav>

</div>
  </main>

  <footer class="footer">
    <div class="footer-inner">


<div class="copyright">
  &copy; 
  <span itemprop="copyrightYear">2023</span>
  <span class="with-love">
    <i class="fa fa-heart"></i>
  </span>
  <span class="author" itemprop="copyrightHolder">Liam</span>
</div>
  <div class="powered-by">Powered by <a href="https://hexo.io/" rel="noopener" target="_blank">Hexo</a> & <a href="https://theme-next.js.org/" rel="noopener" target="_blank">NexT.Gemini</a>
  </div>

    </div>
  </footer>

  
  <div class="back-to-top" role="button" aria-label="Back to top">
    <i class="fa fa-arrow-up fa-lg"></i>
    <span>0%</span>
  </div>

<noscript>
  <div class="noscript-warning">Theme NexT works best with JavaScript enabled</div>
</noscript>


  <script src="https://cdnjs.cloudflare.com/ajax/libs/animejs/3.2.1/anime.min.js" integrity="sha256-XL2inqUJaslATFnHdJOi9GfQ60on8Wx1C2H8DYiN1xY=" crossorigin="anonymous"></script>
<script src="/js/comments.js"></script><script src="/js/utils.js"></script><script src="/js/motion.js"></script><script src="/js/next-boot.js"></script>

  <script src="https://cdnjs.cloudflare.com/ajax/libs/hexo-generator-searchdb/1.4.1/search.js" integrity="sha256-1kfA5uHPf65M5cphT2dvymhkuyHPQp5A53EGZOnOLmc=" crossorigin="anonymous"></script>
<script src="/js/third-party/search/local-search.js"></script>


</body>
</html>