ElasticSearch 2.1.1 (1) - Getting Start
Install & Up
cd elasticsearch-2.1.1/bin
./elasticsearch
./elasticsearch --cluster.name my_cluster_name --node.name my_node_name
Cluster Health
curl 'localhost:9200/_cat/health?v'
curl 'localhost:9200/_cat/nodes?v'
List All Indices
curl 'localhost:9200/_cat/indices?v'
Create an Index
curl -XPUT 'localhost:9200/customer?pretty'
{
"acknowledged" : true
}
curl 'localhost:9200/_cat/indices?v'
health | index | pri | rep | docs.count | docs.deleted | store.size | pri.store.size
yellow | customer | 5 | 1 | 0 |0 | 495b | 495b
Index and Query
Index:
curl -XPUT 'localhost:9200/customer/external/1?pretty' -d '
{
"name": "John Doe”
}'
Response:
{
"_index" : "customer”,
"_type" : "external”,
"_id" : "1”,
"_version" : 1,
"created" : true
}
Query:
curl -XGET 'localhost:9200/customer/external/1?pretty'
{
"_index" : "customer",
"_type" : "external",
"_id" : "1",
"_version" : 1,
"found" : true,
"_source" :
{
"name": "John Doe"
}
}
Delete an Index
curl -XDELETE 'localhost:9200/customer?pretty'
{
"acknowledged" : true
}
curl 'localhost:9200/_cat/indices?v'
health | index | pri | rep | docs.count | docs.deleted | store.size | pri.store.size
curl -X
Updating Document
curl -XPOST 'localhost:9200/customer/external/1/_update?pretty' -d
' { "doc": { "name": "Jane Doe" } }'
curl -XPOST 'localhost:9200/customer/external/1/_update?pretty' -d
' { "doc": { "name": "Jane Doe", "age": 20 } }'
Script:
curl -XPOST 'localhost:9200/customer/external/1/_update?pretty' -d
' { "script" : "ctx._source.age += 5" }'
Error:
{
"error" : {
"root_cause" : [ {
"type" : "remote_transport_exception",
"reason" : "[Angelica Jones][127.0.0.1:9300][indices:data/write/update[s]]"
} ],
"type" : "illegal_argument_exception",
"reason" : "failed to execute script",
"caused_by" : {
"type" : "script_exception",
"reason" : "scripts of type [inline], operation [update] and lang [groovy] are disabled"
}
},
"status" : 400
}
Solution:elasticsearch.yml
script.inline: on
script.indexed: on
Deleting Documents
curl -XDELETE 'localhost:9200/customer/external/2?pretty’
The delete-by-query plugin can delete all documents matching a specific query.
Batch Processing
curl -XPOST 'localhost:9200/customer/external/_bulk?pretty' -d
'{"index":{"_id":"1”}}
{"name": "John Doe” }
{"index":{"_id":"2”}}
{"name": "Jane Doe" } ‘
Delete:
curl -XPOST 'localhost:9200/customer/external/_bulk?pretty' -d
' {"update":{"_id":"1”}}
{
"doc": { "name": "John Doe becomes Jane Doe" }
}
{"delete":{"_id":"2"}} ‘
The Search API
curl 'localhost:9200/bank/_search?q=*&pretty’
-
took –
time in milliseconds for Elasticsearch to execute the search
-
timed_out –
tells us if the search timed out or not
-
_shards –
tells us how many shards were searched, as well as a count of the successful/failed searched shards
-
hits –
search results
-
hits.total –
total number of documents matching our search criteria
-
hits.hits –
actual array of search results (defaults to first 10 documents)
-
_score and max_score -
ignore these fields for now
XPOST:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match_all": {} } }'
NO CURSOR DON’T LIKE SQL
Introducing the Query Language
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match_all": {} }, "size": 1 }'
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match_all": {} }, "from": 10, "size": 10 }'
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match_all": {} }, "sort": { "balance": { "order": "desc" } } }’
Executing Searches
Basic Query
-
Fields:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match_all": {} }, "_source": ["account_number", "balance"] }' -
Returns the account numbered 20:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match": { "account_number": 20 } } }' -
Containing the term "mill" in the address:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match": { "address": "mill" } } }' -
Containing the term "mill" or "lane" in the address:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match": { "address": "mill lane" } } }' -
Containing the phrase "mill lane" in the address:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "match_phrase": { "address": "mill lane" } } }'
Boolean Query
-
AND
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "bool": { "must": [ { "match": { "address": "mill" } }, { "match": { "address": "lane" } } ] } } }' -
OR
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "bool": { "should": [ { "match": { "address": "mill" } }, { "match": { "address": "lane" } } ] } } }' -
NOR
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "bool": { "must_not": [ { "match": { "address": "mill" } }, { "match": { "address": "lane" } } ] } } }' -
Anybody who is 40 years old but don’t live in ID(aho):
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "bool": { "must": [ { "match": { "age": "40" } } ], "must_not": [ { "match": { "state": "ID" } } ] } } }'
Range Query:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "query": { "bool": { "must": { "match_all": {} }, "filter": { "range": { "balance": { "gte": 20000, "lte": 30000 } } } } } }'
Executing Aggregations
Groups all the accounts by state, and then returns the top 10 (default) states sorted by count descending (also default):
curl -XPOST 'localhost:9200/bank/_search?pretty' -d '
{
"size": 0,
"aggs": {
"group_by_state": {
"terms": {
"field": "state"
}
}
}
}'
SELECT state, COUNT(*) FROM bank GROUP BY state ORDER BY COUNT(*) DESC
-
Calculates the average account balance by state:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "size": 0, "aggs": { "group_by_state": { "terms": { "field": "state" }, "aggs": { "average_balance": { "avg": { "field": "balance" } } } } } }'
You can nest aggregations inside aggregations arbitrarily to extract pivoted summarizations that you require from your data.
-
Sort on the average balance in descending order:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d ' { "size": 0, "aggs": { "group_by_state": { "terms": { "field": "state", "order": { "average_balance": "desc" } }, "aggs": { "average_balance": { "avg": { "field": "balance" } } } } } }' -
Group by age brackets (ages 20-29, 30-39, and 40-49), then by gender, and then finally get the average account balance, per age bracket, per gender:
curl -XPOST 'localhost:9200/bank/_search?pretty' -d '
{
"size": 0,
"aggs": {
"group_by_age": {
"range": {
"field": "age",
"ranges": [
{
"from": 20,
"to": 30
},
{
"from": 30,
"to": 40
},
{
"from": 40,
"to": 50
}
]
},
"aggs": {
"group_by_gender": {
"terms": {
"field": "gender"
},
"aggs": {
"average_balance": {
"avg": {
"field": "balance"
}
}
}
}
}
}
}
}'
Reference
https://www.elastic.co/guide/en/elasticsearch/reference/current/getting-started.html