Elasticsearch
roadmap.sh: https://roadmap.sh/elasticsearch
Suggested path through the Elasticsearch nodes. Each node links to its lesson when written.
Nodes
Introduction
- what-is-elasticsearch
- search-engine-fundamentals
- elasticsearch-vs-relational-databases
- the-elastic-stack-elk-elastic
- use-cases-search-logging-observability-analytics
- apache-lucene-foundations
- installing-elasticsearch
Core Concepts
- documents
- indices
- fields-data-types
- mappings
- inverted-index
- shards-replicas
- nodes-cluster
- segments
- near-real-time-search
Mappings & Text Analysis
- dynamic-vs-explicit-mapping
- core-field-types-text-keyword-numeric-date-boolean
- object-nested-fields
- analyzers-standard-language-custom
- tokenizers
- token-filters-character-filters
- normalizers
- multi-fields
Indexing Data (CRUD)
- index-api
- get-update-delete-apis
- bulk-api
- reindex-api
- update-by-query-delete-by-query
- optimistic-concurrency-control-versioning
- ingest-pipelines
Querying (Query DSL)
- query-dsl-overview
- query-vs-filter-context
- match-match-phrase-queries
- term-level-queries
- bool-query-must-should-must-not-filter
- range-queries
- full-text-search
- compound-queries
- relevance-scoring-bm25
- pagination-from-size-search-after-scroll
- sorting
- highlighting
Aggregations
- metric-aggregations
- bucket-aggregations
- pipeline-aggregations
- nested-aggregations
- cardinality-percentiles
Advanced Search Features
- suggesters-autocomplete
- fuzzy-wildcard-search
- geo-queries
- percolate-queries
- search-templates
- runtime-fields
- knn-vector-search
Cluster Architecture & Operations
- node-roles-master-data-ingest-coordinating
- discovery-cluster-formation
- shard-allocation-routing
- cluster-health-green-yellow-red
- index-lifecycle-management-ilm
- snapshots-restore
- rolling-upgrades
Performance & Scaling
- sharding-strategy
- index-templates
- data-streams
- hot-warm-cold-architecture
- bulk-indexing-tuning
- caching-query-request-cache
- force-merge-refresh-interval
Security
- authentication-users
- role-based-access-control-rbac
- tls-encryption
- api-keys
- field-document-level-security
- audit-logging
The Elastic Stack
Clients & Ecosystem
- rest-api
- official-language-clients
- elasticsearch-sql
- painless-scripting
- monitoring-alerting
- elastic-cloud-managed-offerings
Resources
See resources.md.
Project ideas
- Index a public dataset (e.g. movies or products), then build a search UI with autocomplete, faceted filtering via aggregations, and BM25-tuned relevance.
- Ship application logs through Filebeat → Elasticsearch → Kibana and build a dashboard with ILM rolling indices over to a cold tier.
- Implement semantic search by generating embeddings for a document corpus and serving results through Elasticsearch kNN / vector queries.