tech
Defaultdeesfrzh

Elasticsearch

Verteilte Such- und Analyse-Engine - Volltextsuche, Log-Analyse, Echtzeit-Datenexploration

TL;DR

Was: Eine verteilte Such- und Analyse-Engine.

Warum: Volltextsuche, Echtzeit-Analysen, Log-Analyse, skalierbar.

Quick Start

Installation mit Docker:

docker run -d --name elasticsearch \
  -p 9200:9200 -p 9300:9300 \
  -e "discovery.type=single-node" \
  -e "xpack.security.enabled=false" \
  docker.elastic.co/elasticsearch/elasticsearch:8.11.0

Verifizieren:

curl http://localhost:9200

Dokument indexieren:

curl -X POST "localhost:9200/users/_doc" \
  -H "Content-Type: application/json" \
  -d '{"name": "John", "email": "[email protected]"}'

Suchen:

curl "localhost:9200/users/_search?q=name:john"

Cheatsheet

OperationEndpoint
Index erstellenPUT /index
Dokument indexierenPOST /index/_doc
Dokument abrufenGET /index/_doc/id
SuchenGET /index/_search
AktualisierenPOST /index/_update/id
LöschenDELETE /index/_doc/id
Index löschenDELETE /index

Gotchas

Index and document operations

# Index mit Mapping erstellen
curl -X PUT "localhost:9200/products" -H "Content-Type: application/json" -d '
{
  "mappings": {
    "properties": {
      "name": { "type": "text" },
      "price": { "type": "float" },
      "tags": { "type": "keyword" }
    }
  }
}'

# Mit spezifischer ID indexieren
curl -X PUT "localhost:9200/products/_doc/1" -H "Content-Type: application/json" -d '
{
  "name": "Laptop",
  "price": 999.99,
  "tags": ["electronics", "computer"]
}'

Search queries

# Match-Abfrage (Volltext)
curl -X GET "localhost:9200/products/_search" -H "Content-Type: application/json" -d '
{
  "query": {
    "match": { "name": "laptop" }
  }
}'

# Bool-Abfrage (komplex)
curl -X GET "localhost:9200/products/_search" -H "Content-Type: application/json" -d '
{
  "query": {
    "bool": {
      "must": [{ "match": { "name": "laptop" }}],
      "filter": [{ "range": { "price": { "lte": 1000 }}}]
    }
  }
}'

Aggregations

curl -X GET "localhost:9200/products/_search" -H "Content-Type: application/json" -d '
{
  "size": 0,
  "aggs": {
    "avg_price": { "avg": { "field": "price" }},
    "by_tag": { "terms": { "field": "tags" }}
  }
}'

Next Steps