干货 | CrateDb在携程机票BI的实践

{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"一、前言"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"随着整个互联网流量红利进入末期,各大厂在着力吸引新客的同时,在既有客户群体的运营上也是煞费苦心,各种提高客户体验、个性化服务的场景层出不穷。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"携程机票大数据部门在实践过程中需要同步数据、选型引擎来存储处理数据,利用接口将模型结果开放给生产环境调用,因此我们的数据存储修炼之旅会涉及到"},{"type":"text","marks":[{"type":"strong"}],"text":"接口现状、接口大道之旅、安装部署、同步数据、生产应用以及未来的趋势-如何实现容器化"},{"type":"text","text":"。这当中,我们遇到了很多问题,也解决了很多问题,本文将分享机票大数据平台在数据存储这一块的实践经验。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"二、机票大数据接口现状"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"携程机票大数据平台接口组碰到的问题:"}]},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如何存储"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如何查询"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如何维护"}]}]}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"2.1 如何存储"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"机票大数据基础架构团队接口组在2018年之前,数据的存储方案基本是:hive、mysql、redis。以下是我们现有的存储选型:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"embedcomp","attrs":{"type":"table","data":{"content":"
接口需求
Hive
Mysql
Redis
性能要求
请求QPS
>1s
<1
<1s
<10

<500ms
>100


<100ms
>100


√"}}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这就造成了机票大数据部门的redis集群内存需求暴涨,目前我们统计redis使用的数据:挂在机票大数据部门的redis集群数量有几十个,内存达到了十几个T。当然接口的性能也达到了前所未有的快速和高效,基本都是10ms左右。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"2.2 如何查询"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Redis的查询方式比较单一:通过唯一key去查询value。这种查询方式在简单的唯一值查询中比较有效,但是当遇到,同一个数据源多关键字查询的时候,就得维护多份数据源。举例:在价格趋势的接口中,我们提供了多种价格趋势组合:国内、国际、单程、往返、航线、航班。如果使用redis存储,需要维护同一份数据多种key的存储方式,极大地浪费了存储空间。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Redis还有一个问题是时间范围的筛选,还是在上面的价格趋势接口中,需要按照查询时间返回历史同期在一定起飞时间范围的价格数据,所以我们需要存储多个时间日期的数据(当然也可以用set等结构,但是会面临如何删除过期数据的问题),同时在查询的时候需要循环取一定时间范围的价格。"}]},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"2.3 如何维护"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"1)接口维护"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"大数据基础平台团队一共维护了几百个接口,其中1\/3的接口是提供数据给调用方的,这当中又有一些接口只是提供简单的查询操作,但就是这些简单的查询,需要我们提供海量的数据存储、快速精准的查询。每个接口的上线需要经过项目资源申请(包括机器资源、人员资源)、数据同步、开发、测试流程,最后才能上线。一整套流程走下来,耗费2-3天\/人,而且基本上都是是重复性的工作。如何解放这些人力和机器资源,就变得很迫切了。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"2)数据同步"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"提供给外部使用的数据大部分都是存储在hive中,在不使用presto api的方式访问时,我们需要将hive数据导入到redis或者mysql中,供接口访问。在zeus平台上,我们建立了各种导数据的流程,如何将这些简单、重复度高的流程自动化呢?"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"整个接口的架构图如下:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/24\/24c5923a25368dcc09a63bae23ec92a8.jpeg","alt":"图片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":"center","origin":null},"content":[{"type":"text","text":"图1 redis\/mysql作为主要存储的架构图"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"三、机票大数据接口的大道之旅"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"认真研究了接口调用方本身的性能,我们发现调用方在调用第三方提供的接口时,基本都是异步进行的。如果把调用方调用的所有第三方接口当成一个木桶,机票大数据基础架构团队的接口就是其中的一块木板,只要不是最短的木板,就可以在保证性能的情况下降低整个接口的响应时间(当然这不是技术上的退步,而是选择合适的方案)。通过上面的存储选型对比之后,发现在100ms-500ms这个性能段里面没有一个合适的存储方案能够提供。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"我们调研了几种NOSQL数据库方案,综合存储、查询等指标发现CrateDB比较符合现实需求。将几种存储做了一个对比,如下:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"embedcomp","attrs":{"type":"table","data":{"content":"
对比
Redis
Mongo
CrateDB
查询速度
<10ms
100ms~500ms
100ms~500ms
SQL
不支持
不支持
支持
数据结构化
不支持
支持
支持
存储机制
hash
Sharding+partition
Sharding+partition
资源利用
内存资源
硬盘+内存
硬盘+内存
数据可重复使用
不支持,单一固定key
支持
支持"}}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"3.1 CrateDB介绍"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"CrateDB是构建在NoSQL(ElasticSearch)基础之上的分布式SQL数据库,它结合了SQL的通晓程度和NoSQL的可扩展性和数据灵活性:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"a、使用SQL处理结构化或非结构化的任何类型的数据"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"b、以实时速度执行SQL查询,甚至JOIN和聚合"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"c、简单缩放"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"3.2 CrateDB与接口存储"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"CrateDB很好地解决了100ms-500ms性能段的短板,并且使用磁盘+内存的方式存储数据,减少了内存的使用。目前在我们生产时间中,通过12台8核24G虚拟机30%的磁盘空间覆盖了10亿数据(如果是redis至少需要300G的内存,如果做slave,容量double)。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"3.3 CrateDB与接口查询"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"CrateDB提供了如MYSQL的表、字段等概念(底层使用ES存储引擎),我们可以将同一份数据源进行多维度的操作,比如上述讲到的价格趋势里面基于航线和航班的价格趋势,这两个接口可以使用同一套数据源,因为航线的价格可以基于航班数据进行聚合操作,这样就大大减少了冗余的数据。同时类MYSQL表的特性使得时间范围的查询变的so easy了。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"3.4 CrateDB与接口维护"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"1)与接口结合使用"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"因为CrateDB支持标准的SQL,我们开发了机票大数据基础平台的通用性api系统,通过将取数逻辑SQL化的方式,同时利用qconfig api将新增的数据需求进行模板化、配置化,统一了接口代码开发的流程。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"配置页面如下:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/66\/669c26a6518c3b07e0814bd670cc86e1.png","alt":"图片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":"center","origin":null},"content":[{"type":"text","text":"图3 接口配置页面"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"2)数据同步"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"通过zeus api将同步数据流程模板化,配置页面如下图。并且在zeus平台上,使用spark shell方式将hive数据导入到CrateDB中,抛弃了以前jar包的方式。这种方案可以在几分钟内导入千万级的数据(取决于CrateDB表的数据结构,减少索引、doc_values以及刷新间隔会都有利于导入的速度)。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/66\/66186d3ad351eb6408915abb90f65a5e.png","alt":"图片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":"center","origin":null},"content":[{"type":"text","text":"图4 zeus流程配置页面"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"3)容器化"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如何更加有效地管理、维护CrateDB集群?为此我们上了k8s,将CrateDB容器化。为了更好地管理这些k8s集群,引入了rancher,rancher是开源的企业级容器管理平台,通过rancher,我们再也不必自己去从头搭建容器服务平台。同时rancher提供了在生产环境中使用的管理docker和kubernetes的全栈化容器部署与管理平台。将网络、磁盘虚拟化之后,资源的利用率大大提高,减少了虚拟机的使用。自动水平扩展,以及pod的监控等特性,都极大地提高了维护CrateDB的能力,我们管理的CrateDB集群如下:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/79\/79e0c98d003358d52fe3aa87b36279f3.png","alt":"图片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":"center","origin":null},"content":[{"type":"text","text":"图5 rancher管理CrateDB集群图"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"3.5 与接口结合的其他优势"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"1)存储机制多样化,底层的存储机制支持多样化的数据类型,同时支持partition、sharding;"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"2)数据结构化,CrateDB提供结构化的展示,有利于数据的可视化以及降低非技术人员的理解难度,解决了redis可读性差的问题;"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"3)存储可靠性,数据持久化存储在磁盘上,支持replica,相比于redis的内存存储更加可靠(当然redis也可以落盘,但这就会限制redis的速度);"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"4)成熟的优化机制,针对es的优化我们有丰富经验的技术人员支持。举个例子:我们有9000万+的用户行程数据,因为数据比较详细,字段的内容比较庞大。通过去掉部分字段的索引,去掉doc_values等操作将数据存储大小从90G降到了30G,同时也提升了搜索速度。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"目前在生产上我们部署了2个CrateDB集群,其中一个集群由12台8核24G内存虚拟机组成。在集群中建立了12个数据表,存储了20+亿条数据,经受了生产的实际考验,接口性能指标如下:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"embedcomp","attrs":{"type":"table","data":{"content":"
数据量
99line
95line
avg
查询特点
描述
10亿+
200ms
80ms
10ms
多关键字、时间范围查询
整个集群请求量1500qps
500w+
150ms
50ms
10ms
多关键字查询、排序
单个表请求量400qps
9000w+
200ms
100ms
60ms
多关键字查询
单个表请求量10qps"}}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"性能满足了大部分调用方的使用需求,同时系统数据上线的流程由以前的申请资源、开发代码、测试、上线,到现在的系统配置、测试、上线,释放了部分的开发资源,并且保证了数据的质量。接口上线时间由以前平均2-3天,缩短为2-3小时。新的接口架构图如下:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/1e\/1ebc38f2b23fd3bd3bbe3ce09dac9a3e.jpeg","alt":"图片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":"center","origin":null},"content":[{"type":"text","text":"图6 CrateDB作为主要存储的架构图"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"四、安装部署"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"CrateDB有官方版以及社区版,为了更好地进行自维护,我们选择了社区版(通过源码编译)。CrateDB的部署与ES的部署基本一致。需要注意的是,在分配内存的时候尽量多留一些内存给系统,这将有利于数据查询速度。部署后的webui如下:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/49\/49b1f4bcecfce06f1321e9ec52260f9d.png","alt":"图片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":"center","origin":null},"content":[{"type":"text","text":"图7 CrateDB webUI"}]},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"五、数仓中的实现"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"目前在数仓中的应用主要体现在各种指标dashboard、metrics的展示,比如fltinsight。与以往通过presto接口获取数据的方式相比,更加直接、高效。而且CrateDB支持各种字段的聚合、统计,是各种指标存储、展示的不二之选。当然后续数仓组也会在数据展示这一块全面推广CrateDB的使用。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"六、小结"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"没有完美的存储方案,只有最适合的存储方案。"},{"type":"text","text":"通过上述机票大数据平台在数据存储这一块的实践经验,相信每个团队在面对选择存储方案的时候,结合自身需求去选择适合自己的存储技术方案,达到“大道”。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"嘉宾介绍:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Loredp,携程数据分析经理,关注大数据存储、大数据处理以及linux等领域。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"本文转载自:携程技术中心(ID:ctriptech)"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"原文链接:"},{"type":"link","attrs":{"href":"https:\/\/mp.weixin.qq.com\/s\/8mLllQZq6E0eePutkr_L1A","title":"xxx","type":null},"content":[{"type":"text","text":"干货 | CrateDb在携程机票BI的实践"}]}]}]}
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