1. ElasticSearch
A search engine “ready to fly”
Medcl/2012/2/18

2. About me
• Medcl
• medcl@sina
• medcl@github
• m@medcl.net
• log.medcl.net

3. Why I am here?
• 好东西需要与大家一起分享！

4. What’s elasticsearch
• “Distributed, (Near) Real Time, Search Engine”
• Open Source（Apache 2.0）
• RESTful
• Free Schema（Dynamic）
• MultiTenant
• Scalable
• High Availability
• Rich Search Features
• Good Extensibility
• ……

5. first impression

8. Let’s start
the trip

9. Debug Tools

10. Index a document
curl –XPOST http://localhost:9200/myindex/share/1
-d’ Field
字段内容
字段名称 RESTful
{ URL地址
"url" : "http://www.lamper.cn/",
"date" : "2012-02-18 13:00:00",
"location" : "beijing,北京"
}’
索引文档内容，
Json格式

11. Index Response
{
"ok": true,
"_index": "myindex",
"_type": "share",
"_id": "1",
"_version": 1
}

12. Explain the url
索引文档
服务器IP地址 索引名称
唯一标识
http://localhost:9200/myindex/share/1
HTTP端口 索引类型名称

13. Query the document
ES服务器地址 类型名称 指定查询条件
curl –XGET
http://localhost:9200/myindex/share/_search?q
=location:beijing
索引名称 搜索RESTful接口
查询条件，
字段名:值

14. Search Response
{ "took": 12, "timed_out": false,
"_shards": { "total": 5, "successful": 5, "failed": 0 },
"hits": {
"total": 1, "max_score": 0.5,
"hits": [ {
"_index": "myindex",
"_type": "share",
"_id": "1",
"_score": 0.5,
"_source": {
"url": "http://www.lamper.cn/",
"date": "2012-02-18 13:00:00",
"location": "beijing,北京"
} } ] }}

15. Queries
http://localhost:9200/myindex/share/_search?q=
beijing
http://localhost:9200/myindex/share,conf/_searc
h?q=beijing
http://localhost:9200/myindex/_search?q=beijing
http://localhost:9200/myindex,myindex2/_search
?q=beijing
http://localhost:9200/_search?q=beijing

16. QueryDSL
curl -XPOST
http://localhost:9200/myindex/_search –d’
{
"query": { Why QueryDSL?
"term": { Filters、Caching、
"location": "beijing" Highlighting、Facet、
ComplexQuery
} ……
}
}’

17. Scalability&HA

18. Distributed Lucene Directory
• Each index is fully sharded with a configurable
number of shards.
• Each shard can have zero or more replicas.
• Read / Search operations performed on either
replica shard.

19. Automatic shard allocation
From:http://www.slideshare.net/elasticsearch/elasticsearch-at-berlinbuzzwords-2010#

20. Scalability
• nodes that can hold data, and nodes that do
not.
• There is no need for a load balancer in
elasticsearch, each node can receive a request,
and if it can’t handle it, it will automatically
delegate it to the appropriate node(s).
• If you want to scale out search, you can simply
have more shard replicas per shard.

21. Transaction log
• Indexed / deleted doc is fully persistent
• No need for a Lucene IndexWriter#commit
• Managed using a transaction log / WAL
• Full single node durability (kill dash 9)
• Utilized when doing hot relocation of shards
• Periodically “flushed” (calling IW#commit)

22. BASE
• Each document you index is there once the
index operation is done.
• No need to commit or something similar to
get everything persisted.
• A shard can have 1 or more replicas for HA.
• Gateway persistency is done in the
background in an async manner.

23. Not Mentioned Here…
• Versioning
• Template
• River
That’s Too Much,
• Percolator Discovery it yourself
• PartialUpdate
• Routing
• Parent-Child Type
• Scripting
• ……

24. Community&Support
• http://github.com/elasticsearch
• http://groups.google.com/group/elasticsearch
• Irc:#elasticsearch@freenode
• qq群：190605846
• http://doc.elasticsearch.cn
• http://s.medcl.net/

25. BTW
• 招人in’
– 分布式
– 高性能
– 海量数据处理
– 个性化推荐 My
– 搜索引擎 Company！
• 对以上任一感兴趣者：
– 欢迎加入我们的团伙!

26. Thank you!