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class="menu__link menu__link--sublist menu__link--sublist-caret" aria-expanded="false" href="/zh-CN/docs/1.5.0/upgrade/upgrade-from-0.X-to-1.0-guide">升级指南</a></div></li></ul></nav></div></aside><main class="docMainContainer_gTbr"><div class="container padding-top--md padding-bottom--lg"><div class="row"><div class="col docItemCol_VOVn"><div class="theme-doc-version-banner alert alert--warning margin-bottom--md" role="alert"><div>This is documentation for <!-- -->Apache Linkis<!-- --> <b>1.5.0</b>, 非最新版本。</div><div class="margin-top--md">有关最新文档，请参阅最新稳定版本<b><a href="/zh-CN/docs/latest/architecture/feature/public-enhancement-services/bml/overview">latest version</a></b> (<!-- -->1.6.0<!-- -->).</div></div><div class="docItemContainer_Djhp"><article><nav class="theme-doc-breadcrumbs breadcrumbsContainer_Z_bl" aria-label="页面路径"><ul class="breadcrumbs" itemscope="" itemtype="https://schema.org/BreadcrumbList"><li class="breadcrumbs__item"><a aria-label="主页面" class="breadcrumbs__link" href="/zh-CN/"><svg viewBox="0 0 24 24" class="breadcrumbHomeIcon_OVgt"><path d="M10 19v-5h4v5c0 .55.45 1 1 1h3c.55 0 1-.45 1-1v-7h1.7c.46 0 .68-.57.33-.87L12.67 3.6c-.38-.34-.96-.34-1.34 0l-8.36 7.53c-.34.3-.13.87.33.87H5v7c0 .55.45 1 1 1h3c.55 0 1-.45 1-1z" fill="currentColor"></path></svg></a></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">架构设计</span><meta itemprop="position" content="1"></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">关键特性架构</span><meta itemprop="position" content="2"></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">公共增强模块</span><meta itemprop="position" content="3"></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">BML</span><meta itemprop="position" content="4"></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="name">总览</span><meta itemprop="position" content="5"></li></ul></nav><span class="theme-doc-version-badge badge badge--secondary">版本：1.5.0</span><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type="button" class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><header><h1>总览</h1></header><h2 class="anchor anchorWithStickyNavbar_LWe7" id="背景">背景<a class="hash-link" href="#背景" title="Direct link to heading"></a></h2><p>BML（物料库服务）是linkis的物料管理系统，主要用来存储用户的各种文件数据，包括用户脚本、资源文件、第三方Jar包等，也可以存储引擎运行时需要使用到的类库。</p><p>具备以下功能点：</p><p>1)、支持各种类型的文件。支持文本形式和二进制形式的文件，如果是在大数据领域的用户，可以将他们的脚本文件、物料压缩包都可以存储到本系统中。</p><p>2)、服务无状态，多实例部署，做到服务高可用。本系统在部署的时候，可以进行多实例部署，每个实例对外独立提供服务，不会互相干扰，所有的信息都是存储在数据库中进行共享。</p><p>3)、使用方式多样。提供Rest接口和SDK两种方式，用户可以根据自己的需要进行选择。</p><p>4)、文件采用追加方式，避免过多的HDFS小文件。HDFS小文件多会导致HDFS整体性能的下降，我们采用了文件追加的方式，将多个版本的资源文件合成一个大文件，有效减少了HDFS的文件数量。</p><p>5)、精确权限控制，用户资源文件内容安全存储。资源文件往往会有重要的内容，用户只希望自己可读</p><p>6)、提供了文件上传、更新、下载等操作任务的生命周期管理。</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="架构图">架构图<a class="hash-link" href="#架构图" title="Direct link to heading"></a></h2><p><img loading="lazy" alt="BML架构图" src="/zh-CN/assets/images/bml-02-130262a1f618d615779b1fa2b2f0e570.png" width="665" height="460" class="img_ev3q"></p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="架构说明">架构说明<a class="hash-link" href="#架构说明" title="Direct link to heading"></a></h2><p>1、Service层 包含资源管理、上传资源、下载资源、共享资源还有工程资源管理。</p><p>资源管理负责资源的增删改查操作，访问权限控制，文件是否过期等基本操作。</p><p>2、文件版本控制 |
| 每个BML资源文件都是具有版本信息的，同一个资源每次更新操作都会产生一个新的版本，当然也支持历史版本的查询和下载操作。BML使用版本信息表记录了每个版本的资源文件HDFS存储的偏离位置和大小，可以在一个HDFS文件上存储多个版本的数据。</p><p>3、资源文件存储 |
| 主要使用HDFS文件作为实际的数据存储，HDFS文件可以有效保证物料库文件不被丢失，文件采用追加方式，避免过多的HDFS小文件。</p><h3 class="anchor anchorWithStickyNavbar_LWe7" id="核心流程">核心流程<a class="hash-link" href="#核心流程" title="Direct link to heading"></a></h3><p><strong>上传文件：</strong></p><ol><li><p>判断用户上传文件的操作类型，属于首次上传还是更新上传，如果是首次上传需要新增一条资源信息记录，系统已经为这个资源生成了一个全局唯一标识的resource_id和一个资源放置的位置resource_location。资源A的第一个版本A1需要在HDFS文件系统中resource_location位置进行存储。存储完之后，就可以得到第一个版本记为V00001，如果是更新上传需要查找上次最新的版本。</p></li><li><p>上传文件流到指定的HDFS文件，如果是更新则采用文件追加的方式加到上次内容的末尾。</p></li><li><p>新增一条版本记录，每次上传都会产生一条新的版本记录。除了记录这个版本的元数据信息外，最重要的是记录了该版本的文件的存储位置，包括文件路径，起始位置，结束位置。</p></li></ol><p><strong>下载文件：</strong></p><ol><li><p>用户下载资源的时候，需要指定两个参数一个是resource_id，另外一个是版本version，如果不指定version的话，默认下载最新版本。</p></li><li><p>用户传入resource_id和version两个参数到系统之后，系统查询resource_version表，查到对应的resource_location和start_byte和end<!-- -->_<!-- -->byte进行下载，通过流处理的skipByte方法，将resource<!-- -->_<!-- -->location的前(start_byte-1)个字节跳过，然后读取到end_byte |
| 字节数。读取成功之后，将流信息返回给用户。</p></li><li><p>在resource_download_history中插入一条下载成功的记录</p></li></ol><h2 class="anchor anchorWithStickyNavbar_LWe7" id="数据库设计">数据库设计<a class="hash-link" href="#数据库设计" title="Direct link to heading"></a></h2><p>1、资源信息表(resource)</p><table><thead><tr><th>字段名</th><th>作用</th><th>备注</th></tr></thead><tbody><tr><td>resource_id</td><td>全局唯一标识一个资源的字符串</td><td>可以采用UUID进行标识</td></tr><tr><td>resource_location</td><td>存放资源的位置</td><td>例如 hdfs:///tmp/bdp/\${用户名}/</td></tr><tr><td>owner</td><td>资源的所属者</td><td>例如 zhangsan</td></tr><tr><td>create_time</td><td>记录创建时间</td><td></td></tr><tr><td>is_share</td><td>是否共享</td><td>0表示不共享，1表示共享</td></tr><tr><td>update<!-- -->_<!-- -->time</td><td>资源最后的更新时间</td><td></td></tr><tr><td>is<!-- -->_<!-- -->expire</td><td>记录资源是否过期</td><td></td></tr><tr><td>expire_time</td><td>记录资源过期时间</td><td></td></tr></tbody></table><p>2、资源版本信息表（resource_version）</p><table><thead><tr><th>字段名</th><th>作用</th><th>备注</th></tr></thead><tbody><tr><td>resource_id</td><td>唯一标识资源</td><td>联合主键</td></tr><tr><td>version</td><td>资源文件的版本</td><td></td></tr><tr><td>start_byte</td><td>资源文件开始字节数</td><td></td></tr><tr><td>end<!-- -->_<!-- -->byte</td><td>资源文件结束字节数</td><td></td></tr><tr><td>size</td><td>资源文件大小</td><td></td></tr><tr><td>resource_location</td><td>资源文件放置位置</td><td></td></tr><tr><td>start_time</td><td>记录上传的开始时间</td><td></td></tr><tr><td>end<!-- -->_<!-- -->time</td><td>记录上传的结束时间</td><td></td></tr><tr><td>updater</td><td>记录更新用户</td><td></td></tr></tbody></table><p>3、资源下载历史表(resource_download_history)</p><table><thead><tr><th>字段</th><th>作用</th><th>备注</th></tr></thead><tbody><tr><td>resource_id</td><td>记录下载资源的resource_id</td><td></td></tr><tr><td>version</td><td>记录下载资源的version</td><td></td></tr><tr><td>downloader</td><td>记录下载的用户</td><td></td></tr><tr><td>start<!-- -->_<!-- -->time</td><td>记录下载时间</td><td></td></tr><tr><td>end<!-- -->_<!-- -->time</td><td>记录结束时间</td><td></td></tr><tr><td>status</td><td>记录是否成功</td><td>0表示成功，1表示失败</td></tr><tr><td>err<!-- -->_<!-- -->msg</td><td>记录失败原因</td><td>null表示成功，否则记录失败原因</td></tr></tbody></table></div><footer class="theme-doc-footer docusaurus-mt-lg"><div class="theme-doc-footer-edit-meta-row row"><div class="col"><a href="https://github.com/apache/linkis-website/edit/dev/i18n/zh-CN/docusaurus-plugin-content-docs/version-1.5.0/architecture/feature/public-enhancement-services/bml/overview.md" 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