elasticsearch
Use this skill for Elasticsearch(ES)相关设计、性能与运维(DBA/中间件)任务。
Defaults / assumptions to confirm
- •ES version and deployment (self-hosted / managed)
- •Cluster topology (nodes, roles, storage type)
- •Data volume and retention requirements
- •Query patterns (search vs analytics) and latency SLO
Workflow
- •Understand use-cases and query patterns
- •Primary user journeys: keyword search, filtering, aggregations, sorting.
- •Write patterns: append-only logs vs frequent updates.
- •Required consistency and freshness (near real-time delay tolerance).
- •Index & mapping design
- •Define index naming convention and templates.
- •Choose correct field types (
keywordvstext,date,long,scaled_float). - •Analyze/analyzer strategy for language (e.g., Chinese tokenizer) if needed.
- •Avoid mapping explosion; control dynamic mappings.
- •Plan
_sourceand stored fields usage; consider doc values.
- •Shards and replicas
- •Pick shard count with future growth and reindex cost in mind.
- •Avoid too many small shards; target shard size range (e.g., 10–50GB) depending on workload.
- •Set replicas for availability and read scaling.
- •Query tuning
- •Use
profileand slow logs to find bottlenecks. - •Reduce heavy aggregations; precompute when possible.
- •Use filters with
keywordfields; cache-friendly queries. - •Pagination: prefer
search_afterfor deep pages; avoid largefrom+size.
- •Lifecycle management
- •Use ILM (hot-warm-cold-delete) for time-series data.
- •Rollover policies by size/time; manage retention.
- •Cluster operations & stability
- •Monitor heap, GC, CPU, disk watermarks, thread pool rejections.
- •Detect hot keys/indices; rebalance shards carefully.
- •Snapshot/restore; restore drills; retention policy.
- •Safe changes
- •Mapping changes often require reindex; plan alias-based migrations.
- •Use index aliases for zero-downtime cutover.
- •Upgrade runbook: compatibility, rolling upgrade, backout plan.
Outputs
- •Mapping/index template proposal + rationale.
- •Shard/replica sizing plan + expected capacity.
- •Performance diagnosis report (evidence → root cause → fixes).
- •Migration plan (reindex + alias cutover + verification).