This curriculum spans the equivalent depth and technical granularity of a multi-workshop optimization engagement with a production ELK Stack environment, addressing query performance, index lifecycle, cluster architecture, and security constraints as they arise in large-scale, real-time data platforms.
Module 1: Understanding Query Performance Fundamentals in Elasticsearch
- Selecting appropriate query types (term vs. match vs. query_string) based on data structure and search intent to balance recall and performance.
- Configuring index mapping to avoid mapping explosions, particularly when using dynamic templates with nested objects or large numbers of fields.
- Deciding between keyword and text field types during index design to prevent unnecessary full-text analysis on exact-match fields.
- Managing the impact of _all and field data caching by disabling unused features and monitoring cache hit ratios under production query loads.
- Implementing source filtering to reduce network overhead when only a subset of stored fields is required in query responses.
- Adjusting request cache settings for time-series indices to avoid caching low-hit-rate queries while preserving performance for frequently repeated aggregations.
Module 2: Index Design and Data Lifecycle Optimization
- Designing time-based index patterns with appropriate rollover conditions (size, age, document count) to maintain consistent shard sizes and query performance.
- Implementing Index State Management (ISM) policies to automate transitions from hot to warm phases, including forced merge and shard allocation changes.
- Choosing between index templates and legacy template patterns while ensuring version compatibility and avoiding template precedence conflicts.
- Partitioning large indices using data streams and configuring write index routing to support high ingestion rates without query degradation.
- Defining shard count per index based on data volume, node resources, and concurrency requirements to prevent under-sharding or over-sharding.
- Using shrink and split APIs to reconfigure shard counts on indices that were initially mis-sized, considering cluster load and recovery impact.
Module 3: Query DSL and Execution Efficiency
- Replacing expensive queries like wildcard and regexp with ngram or edge-ngram pre-processing where feasible to reduce execution latency.
- Applying query context versus filter context correctly to leverage caching on non-scoring boolean clauses in compound queries.
- Optimizing nested queries by limiting depth, using nested field norms, and avoiding unnecessary inner hits in responses.
- Controlling aggregation cardinality using sampler and diversified sampler buckets to reduce memory consumption on high-cardinality fields.
- Setting track_total_hits appropriately in queries where exact counts are unnecessary, reducing coordination overhead on large result sets.
- Using the profile API to diagnose slow queries in staging environments and identifying costly components such as script evaluation or regex parsing.
Module 4: Aggregation Performance and Memory Management
- Choosing between terms, composite, and histogram aggregations based on cardinality and pagination requirements to prevent heap exhaustion.
- Setting shard_size on terms aggregations to balance accuracy and memory usage, particularly when dealing with imbalanced term distribution.
- Configuring timeout and circuit breaker limits for aggregations to prevent node-level outages during complex analytical queries.
- Using pipeline aggregations judiciously to avoid multi-pass processing, especially when combining bucket and metric operations.
- Pre-aggregating high-frequency metrics in ingest pipelines or external systems when real-time precision is not required.
- Monitoring field data cache usage per field and disabling fielddata on text fields that are not used for sorting or aggregations.
Module 5: Cluster Architecture and Search Performance
- Allocating dedicated coordinating nodes to isolate search traffic from ingestion and master duties in large-scale deployments.
- Configuring search thread pools and queue sizes to handle burst loads without rejecting valid requests or overloading nodes.
- Using shard request cache effectively by structuring time-based queries to align with index boundaries and cache key patterns.
- Implementing adaptive replica selection to route search requests to the closest or least-loaded replica based on topology and load metrics.
- Adjusting refresh_interval per index based on search freshness requirements, reducing I/O pressure on high-ingest indices.
- Enabling and tuning slow query logging to capture and analyze queries exceeding defined latency thresholds across time-series indices.
Module 6: Security, Access Control, and Query Impact
- Designing role-based index patterns and field-level security to minimize query overhead from dynamic filters and document masking.
- Assessing performance impact of query-level security filters applied via role queries and optimizing filter complexity.
- Using index patterns in roles that align with data lifecycle phases to avoid scanning irrelevant or deleted indices.
- Monitoring authentication and authorization latency in clusters with external identity providers under peak search concurrency.
- Implementing search guard or OpenSearch Security rules that avoid per-document scripts in favor of pre-filtered index aliases.
- Testing query performance with realistic user roles to identify bottlenecks introduced by security-enforced query rewrites.
Module 7: Monitoring, Diagnostics, and Continuous Tuning
- Instrumenting search latency and throughput using Elasticsearch monitoring APIs and correlating with Kibana query patterns.
- Using the tasks API to identify long-running search operations and cancel or optimize them during peak hours.
- Integrating slow log output with centralized logging to analyze query patterns and identify recurring performance outliers.
- Establishing baseline query performance metrics for critical dashboards and setting alerts on deviations.
- Conducting A/B testing of query rewrites or index changes in shadow mode using tools like Replayer to assess impact.
- Scheduling periodic index optimization tasks such as force merge and cache warming during maintenance windows based on usage patterns.
Module 8: Advanced Query Patterns and Real-World Trade-offs
- Implementing asynchronous search for long-running aggregations to free up coordinating node resources and improve user experience.
- Evaluating the cost of runtime fields versus indexed fields for frequently queried computed values.
- Using point-in-time (PIT) searches for consistent large result sets while managing the overhead of maintaining search contexts.
- Designing query fallback strategies for partial index availability in multi-region deployments with cross-cluster search.
- Optimizing geo-distance and geo-bounding box queries with geotile grid aggregations and index precision tuning.
- Integrating external data via lookup joins in ingest pipelines to avoid expensive runtime joins during search execution.