Apache Solr vs Elasticsearch

╰+哭是因爲堅強的太久メ 2022-04-08 12:20 234阅读 0赞

我们都知道业界两个最流行的开源搜索引擎，Solr和ElasticSearch。两者都建立在Apache Lucene开源平台之上，它们的主要功能非常相似，但是在部署的易用性，可扩展性和其他功能方面也存在巨大差异。

### 1. Apache Solr ###

在过去的十年里，solr发展壮大，拥有广泛的用户群体。solr提供分布式索引、分片、副本集、负载均衡和自动故障转移和恢复功能。不少互联网巨头，如Netflix，eBay，Instagram和Amazon（CloudSearch）均使用Solr。

solr的主要特点：

*  全文索引
 *  高亮
 *  分面搜索
 *  实时索引
 *  动态聚类
 *  数据库集成
 *  NoSQL特性和丰富的文档处理（例如Word和PDF文件）

### 2. Elasticsearch ###

Elasticsearch在Solr推出几年后才面世的，通过REST和schema-free（**不需要预先定义 Schema，solr是需要预先定义的**）的JSON文档提供分布式、多租户全文搜索引擎。Elasticsearch可扩展为准实时搜索引擎。其中一个关键特性是多租户功能，可根据不同的用途分索引，可以同时操作多个索引。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2l0c29mdGNoZW5mZWk_size_16_color_FFFFFF_t_70][]

上图中，可以在google中的[搜索热度][Link 1]，可以看出在2013年后，Elasticsearch与Solr相比具有很大的吸引力，但这并不意味着Apache Solr已经死了。虽然不少人不认可，但Solr仍然是最流行的搜索引擎之一，具有强大的开源社区支持。

**性能对比**

大型互联网公司，实际生产环境测试，将搜索引擎从Solr转到Elasticsearch以后的平均查询速度有了50倍的提升。

### 3. 功能特性的差异 ###

说实话，有些特性我确实没研究过，结论也是引入[Kelvin Tan][]。![83377247][]

**API**

<table> 
 <thead> 
  <tr> 
   <th style="width:212px;">Feature</th> 
   <th style="width:263px;">Solr 7.2.1</th> 
   <th style="width:374px;">Elasticsearch 6.2.4</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="width:212px;">Format</td> 
   <td style="width:263px;">XML, CSV, JSON</td> 
   <td style="width:374px;">JSON</td> 
  </tr> 
  <tr> 
   <td style="width:212px;">HTTP REST API</td> 
   <td style="width:263px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:374px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:212px;">Binary API <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:263px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> SolrJ</td> 
   <td style="width:374px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> TransportClient, Thrift (through a <a href="https://github.com/elasticsearch/elasticsearch-transport-thrift" rel="nofollow">plugin</a>)</td> 
  </tr> 
  <tr> 
   <td style="width:212px;">JMX support</td> 
   <td style="width:263px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:374px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"> ES specific stats are exposed through the REST API</td> 
  </tr> 
  <tr> 
   <td style="width:212px;">Official client libraries <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:263px;">Java</td> 
   <td style="width:374px;">Java, Groovy, PHP, Ruby, Perl, Python, .NET, Javascript <a href="https://www.elastic.co/guide/en/elasticsearch/client/index.html" rel="nofollow">Official list of clients</a></td> 
  </tr> 
  <tr> 
   <td style="width:212px;">Community client libraries <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:263px;">PHP, Ruby, Perl, Scala, Python, .NET, Javascript, Go, Erlang, Clojure</td> 
   <td style="width:374px;">Clojure, Cold Fusion, Erlang, Go, Groovy, Haskell, Java, JavaScript, .NET, OCaml, Perl, PHP, Python, R, Ruby, Scala, Smalltalk, Vert.x <a href="https://www.elastic.co/guide/en/elasticsearch/client/community/current/index.html" rel="nofollow">Complete list</a></td> 
  </tr> 
  <tr> 
   <td style="width:212px;">3rd-party product integration (open-source)<a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:263px;">Drupal, Magento, Django, ColdFusion, Wordpress, OpenCMS, Plone, Typo3, ez Publish, Symfony2, Riak (via Yokozuna)</td> 
   <td style="width:374px;">Drupal, Django, Symfony2, Wordpress, CouchBase</td> 
  </tr> 
  <tr> 
   <td style="width:212px;">3rd-party product integration (commercial)<a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:263px;">DataStax Enterprise Search, Cloudera Search, Hortonworks Data Platform, MapR</td> 
   <td style="width:374px;">SearchBlox, Hortonworks Data Platform, MapR etc <a href="https://www.elastic.co/guide/en/elasticsearch/plugins/current/integrations.html" rel="nofollow">Complete list</a></td> 
  </tr> 
  <tr> 
   <td style="width:212px;">Output<a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:263px;">JSON, XML, PHP, Python, Ruby, CSV, Velocity, XSLT, native Java</td> 
   <td style="width:374px;">JSON, XML/HTML (via <a href="http://blog.zenika.com/index.php?post/2012/12/20/Introducing-the-Elasticsearch-View-Plugin" rel="nofollow">plugin</a>)</td> 
  </tr> 
 </tbody> 
</table>

**Infrastructure**

<table> 
 <thead> 
  <tr> 
   <th>Feature</th> 
   <th>Solr 7.2.1</th> 
   <th>Elasticsearch 6.2.4</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>Master-slave replication</td> 
   <td><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"> Not an issue because shards are replicated across nodes.</td> 
  </tr> 
  <tr> 
   <td>Integrated snapshot and restore</td> 
   <td>Filesystem</td> 
   <td>Filesystem, AWS Cloud Plugin for S3 repositories, HDFS Plugin for Hadoop environments, Azure Cloud Plugin for Azure storage repositories</td> 
  </tr> 
 </tbody> 
</table>

**Indexing**

<table> 
 <thead> 
  <tr> 
   <th style="width:178px;">Feature</th> 
   <th style="width:274px;">Solr 7.2.1</th> 
   <th style="width:396px;">Elasticsearch 6.2.4</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="width:178px;">Data Import</td> 
   <td style="width:274px;">DataImportHandler - JDBC, CSV, XML, Tika, URL, Flat File</td> 
   <td style="width:396px;"><span style="color:#800000;">[DEPRECATED in 2.x]</span> Rivers modules - ActiveMQ, Amazon SQS, CouchDB, Dropbox, DynamoDB, FileSystem, Git, GitHub, Hazelcast, JDBC, JMS, Kafka, LDAP, MongoDB, neo4j, OAI, RabbitMQ, Redis, RSS, Sofa, Solr, St9, Subversion, Twitter, Wikipedia</td> 
  </tr> 
  <tr> 
   <td style="width:178px;">ID field for updates and deduplication</td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">DocValues <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Partial Doc Updates <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> with stored fields</td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> with _source field</td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Custom Analyzers and Tokenizers <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Per-field analyzer chain <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Per-doc/query analyzer chain <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Index-time synonyms <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Supports Solr and Wordnet synonym format</td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Query-time synonyms <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Solr 6 provides proper multi-word synonyms via SynonymGraphFilter</td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Synonym Graph Token Filter is in beta in ES 6.2</td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Multiple indexes <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Near-Realtime Search/Indexing <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Complex documents <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Schemaless <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Multiple document types per schema <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"> One set of fields per schema, one schema per core</td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Online schema changes <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Schemaless mode or via dynamic fields.</td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Only backward-compatible changes.</td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Apache Tika integration <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Dynamic fields <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Field copying <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> via multi-fields</td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Hash-based deduplication <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"><a href="https://www.elastic.co/guide/en/elasticsearch/plugins/current/mapper-murmur3.html" rel="nofollow">Murmur plugin</a> or <a href="https://github.com/YannBrrd/elasticsearch-entity-resolution" rel="nofollow">ER plugin</a></td> 
  </tr> 
  <tr> 
   <td style="width:178px;">Index-time sorting <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:274px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"></td> 
   <td style="width:396px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
 </tbody> 
</table>

**Searching**

<table> 
 <thead> 
  <tr> 
   <th style="width:211px;">Feature</th> 
   <th style="width:324px;">Solr 7.2.1</th> 
   <th style="width:313px;">Elasticsearch 6.2.4</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="width:211px;">Lucene Query parsing <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Structured Query DSL <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"><a href="https://lucene.apache.org/solr/guide/7_1/json-query-dsl.html" rel="nofollow">JSON Query DSL</a> is new in Solr 7.x</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Span queries <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> via <a href="https://issues.apache.org/jira/browse/SOLR-2703" rel="nofollow">SOLR-2703</a></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Spatial/geo search <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Multi-point spatial search <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Faceting <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Top N term accuracy can be controlled with <a href="https://www.elastic.co/guide/en/elasticsearch/reference/2.1/search-aggregations-bucket-terms-aggregation.html#_shard_size_2" rel="nofollow">shard_size</a></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Advanced Faceting <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> New <a href="https://lucene.apache.org/solr/guide/7_2/analytics.html" rel="nofollow">Analytics component</a> and <a href="http://yonik.com/json-facet-api/" rel="nofollow">JSON faceting API</a></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"><a href="http://www.elasticsearch.org/blog/data-visualization-elasticsearch-aggregations" rel="nofollow">blog post</a></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Geo-distance Faceting</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Pivot Facets <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">More Like This</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Boosting by functions <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Boosting using scripting languages <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Push Queries <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Via <a href="https://lucene.apache.org/solr/guide/7_2/streaming-expressions.html" rel="nofollow">Streaming Expressions</a></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Percolation. Distributed percolation supported in 1.0</td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Field collapsing/Results grouping <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Query Re-Ranking <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> via <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-rescore.html" rel="nofollow">Rescoring</a> or <a href="https://github.com/codelibs/elasticsearch-dynarank" rel="nofollow">a plugin</a></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Index-based Spellcheck <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"><a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/search-suggesters-phrase.html" rel="nofollow">Phrase Suggester</a></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Wordlist-based Spellcheck <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Autocomplete</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Document-oriented Autocomplete</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"> Solr suggester return phrases not documents.</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Learning to Rank</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Via <a href="https://github.com/o19s/elasticsearch-learning-to-rank" rel="nofollow">https://github.com/o19s/elasticsearch-learning-to-rank</a></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Query elevation <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"><a href="https://github.com/elasticsearch/elasticsearch/issues/1066#issuecomment-8625739" rel="nofollow">workaround</a></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Intra-index joins <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> via parent-child query</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> via <em>has_children</em> and <em>top_children</em> queries</td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Inter-index joins <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Joined index has to be single-shard and replicated across all nodes.</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Resultset Scrolling <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> via <em>scan</em> search type</td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Filter queries <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> also supports filtering by native scripts</td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Filter execution order <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> local params and <em>cache</em> property</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Alternative QueryParsers <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> DisMax, eDisMax</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> query_string, dis_max, match, multi_match etc</td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Negative boosting <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> but awkward. Involves positively boosting the inverse set of negatively-boosted documents.</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Search across multiple indexes</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> it can search across multiple compatible collections</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Result highlighting</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Custom Similarity <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Searcher warming on index reload <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"><a href="http://www.elasticsearch.org/guide/reference/api/admin-indices-warmers/" rel="nofollow">Warmers API</a></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Term Vectors API</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">SQL queries</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Via <a href="https://lucene.apache.org/solr/guide/7_2/parallel-sql-interface.html#parallel-sql-interface" rel="nofollow">Parallel SQL</a>. SolrCloud only</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"></td> 
  </tr> 
  <tr> 
   <td style="width:211px;">Distributed Map/Reduce processing</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Via <a href="https://lucene.apache.org/solr/guide/7_2/streaming-expressions.html" rel="nofollow">Streaming Expressions</a>. SolrCloud only</td> 
   <td style="width:313px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"></td> 
  </tr> 
 </tbody> 
</table>

**Distributed**

<table> 
 <thead> 
  <tr> 
   <th style="width:130px;">Feature</th> 
   <th style="width:324px;">Solr 7.2.1</th> 
   <th style="width:394px;">Elasticsearch 6.2.4</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="width:130px;">Self-contained cluster <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"> Depends on separate ZooKeeper server</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Only Elasticsearch nodes</td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Automatic node discovery</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> ZooKeeper</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> internal Zen Discovery or ZooKeeper</td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Partition tolerance</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> The partition without a ZooKeeper quorum will stop accepting indexing requests or cluster state changes, while the partition with a quorum continues to function.</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"> Partitioned clusters can diverge unless discovery.zen.minimum_master_nodes set to at least N/2+1, where N is the size of the cluster. If configured correctly, the partition without a quorum will stop operating, while the other continues to work. See <a href="http://elasticsearch-users.115913.n3.nabble.com/Split-brain-td3620149.html" rel="nofollow">this</a></td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Automatic failover</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> If all nodes storing a shard and its replicas fail, client requests will fail, unless requests are made with the shards.tolerant=true parameter, in which case partial results are retuned from the available shards.</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Automatic leader election</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Shard replication</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Sharding <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Automatic shard rebalancing <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Solr Autoscaling is new in Solr 7.</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> it can be machine, rack, availability zone, and/or data center aware. Arbitrary tags can be assigned to nodes and it can be configured to not assign the same shard and its replicates on a node with the same tags.</td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Change # of shards</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Shards can be added (when using implicit routing) or split (when using compositeId). Cannot be lowered. Replicas can be increased anytime.</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"> each index has 5 shards by default. Number of primary shards cannot be changed once the index is created. Replicas can be increased anytime. The <a href="https://www.elastic.co/guide/en/elasticsearch/reference/6.2/indices-shrink-index.html" rel="nofollow">Shrink Index API</a> lets you reindex the index into a new index with fewer shards.</td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Shard splitting</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"></td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"> You can use the <a href="https://www.elastic.co/guide/en/elasticsearch/reference/6.2/indices-split-index.html" rel="nofollow">Index Splitting API</a> to index to a new index with primary shards split.</td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Relocate shards and replicas <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> can be done by creating a shard replicate on the desired node and then removing the shard from the source node</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> can move shards and replicas to any node in the cluster on demand</td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Control shard routing <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"><em>shards</em> or <em>_route_</em> parameter</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"><em>routing</em> parameter</td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Pluggable shard/replica assignment</td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> New Autoscaling API replaces the old rule-based replica assignment</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Probabilistic shard balancing with <a href="https://github.com/datarank/tempest" rel="nofollow">Tempest plugin</a></td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Avoid duplicate indexing on replicas <a href="http://solr-vs-elasticsearch.com/#" rel="nofollow"><img alt="" src="http://solr-vs-elasticsearch.com/img/help.png"></a></td> 
   <td style="width:324px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/tick.png"> Solr 7 provides 3 kinds of replica types: NRT (default and the pre-Solr 7 behavior), tlog and pull. Non-SolrCloud master-slave replication can be achieved with tlog replica types.</td> 
   <td style="width:394px;"><img alt="" src="http://solr-vs-elasticsearch.com/img/cross.png"></td> 
  </tr> 
  <tr> 
   <td style="width:130px;">Consistency</td> 
   <td style="width:324px;">Indexing requests are synchronous with replication. A indexing request won't return until all replicas respond. No check for downed replicas. They will catch up when they recover. When new replicas are added, they won't start accepting and responding to requests until they are finished replicating the index.</td> 
   <td style="width:394px;">Replication between nodes is synchronous by default, thus ES is consistent by default, but it can be set to asynchronous on a per document indexing basis. Index writes can be configured to fail is there are not sufficient active shard replicas. The default is quorum, but all or one are also available.</td> 
  </tr> 
 </tbody> 
</table>

### 4. 总结 ###

*  Solr 利用 Zookeeper 进行分布式管理，而 Elasticsearch 自身带有分布式协调管理功能;
 *  Solr 支持更多格式的数据，而 Elasticsearch 仅支持json文件格式；
 *  Solr 官方提供的功能更多，而 Elasticsearch 本身更注重于核心功能，高级功能多有第三方插件提供；
 *  Solr 在传统的搜索应用中表现好于 Elasticsearch，但在处理实时搜索应用时效率明显低于 Elasticsearch。

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2l0c29mdGNoZW5mZWk_size_16_color_FFFFFF_t_70]: /images/20220405/9310d3b8304f4dfaac02a3e7ac31eeb8.png
[Link 1]: https://trends.google.com/trends/explore?date=all&q=apache%20solr,elasticsearch
[Kelvin Tan]: http://solr-vs-elasticsearch.com/
[83377247]: /images/20220405/b24f7b8293b042d2887dba23ff4d1ce4.png