This curriculum spans the technical breadth of a multi-workshop performance optimisation engagement, addressing the same shard-level tuning, ingest pipeline refinement, and JVM-level adjustments typically tackled during intensive cluster-wide audits in production ELK environments.
Module 1: Architectural Assessment and Performance Baselines
- Decide between hot-warm-cold architectures based on data access patterns and retention requirements for time-series indices.
- Configure index lifecycle policies to automate rollover and shrink operations without disrupting ingestion throughput.
- Size Elasticsearch data nodes based on shard density, memory pressure, and disk I/O capacity to avoid garbage collection spikes.
- Establish performance baselines using Elasticsearch’s _nodes/stats and _cluster/health endpoints under production-like query loads.
- Implement dedicated master and ingest nodes in large clusters to isolate coordination and transformation overhead from search workloads.
- Evaluate the impact of replica count on search latency and recovery time during node failures in multi-AZ deployments.
Module 2: Index Design and Shard Optimization
- Calculate optimal primary shard count per index based on data volume, growth rate, and maximum node capacity to prevent hotspots.
- Apply index templates with appropriate codec settings (e.g., best_compression vs default) to balance storage savings and query speed.
- Use shrink and split APIs to reconfigure shard count on existing indices when initial allocation proves suboptimal.
- Implement time-based index naming conventions with aliases to streamline rollover and simplify query routing.
- Disable _source or enable source filtering on high-volume indices when full document retrieval is unnecessary.
- Prevent mapping explosions by setting strict limits on dynamic field generation and using explicit field mappings for critical fields.
Module 3: Query and Search Performance Engineering
- Refactor wildcard and regex queries into term-based lookups using keyword fields and proper analyzers to reduce execution cost.
- Enforce query timeouts and result size limits in Kibana and application-level search APIs to prevent cluster resource exhaustion.
- Use profile API to diagnose slow search requests and identify expensive query clauses or inefficient aggregations.
- Implement search templates with parameterized queries to reduce parsing overhead and improve caching efficiency.
- Configure request and shard-level circuit breakers to protect nodes from out-of-memory conditions during complex aggregations.
- Optimize aggregation performance by precomputing metrics using rollup indices or transforms for high-cardinality fields.
Module 4: Ingest Pipeline Efficiency and Log Processing
- Offload parsing and transformation from ingest nodes to Logstash or Beats when CPU-bound pipelines degrade indexing throughput.
- Sequence pipeline processors to minimize data duplication, placing conditional checks before costly mutations.
- Use dissect or CSV processors instead of grok patterns where log formats are predictable to reduce CPU utilization.
- Cache frequently used pipeline configurations in persistent memory to reduce reload latency during node restarts.
- Monitor pipeline drop rates and queue sizes to detect bottlenecks in Beats-to-Logstash or Logstash-to-Elasticsearch flows.
- Implement dead-letter queues for failed documents to enable root cause analysis without blocking active ingestion.
Module 5: Cluster Resource Management and JVM Tuning
- Set heap size to 50% of physical RAM, capped at 32GB, to optimize JVM compressed oops and minimize GC pauses.
- Configure G1GC tuning parameters (e.g., MaxGCPauseMillis, InitiatingHeapOccupancyPercent) based on observed pause patterns.
- Isolate indexing and search workloads using node roles and attribute-based routing to prevent interference.
- Monitor thread pool rejections in bulk, search, and write pools to adjust queue sizes or scale node capacity.
- Adjust file descriptor limits and mmap counts on host OS to support large numbers of open index segments.
- Use cgroups or container resource limits in Kubernetes to prevent Elasticsearch containers from exceeding allocated memory.
Module 6: Monitoring, Alerting, and Capacity Planning
- Deploy Elasticsearch’s monitoring features to ship cluster metrics to a separate monitoring cluster to avoid self-interference.
- Configure alert thresholds on disk usage, shard relocation rates, and pending tasks to detect degradation before outages.
- Use historical index growth rates and retention policies to project storage needs and plan node expansion cycles.
- Integrate external monitoring tools (e.g., Prometheus, Zabbix) with Elasticsearch’s HTTP APIs for centralized visibility.
- Track indexing latency percentiles to identify pipeline bottlenecks or queue backpressure in real time.
- Automate cluster health checks in CI/CD pipelines to prevent deployment of configurations that violate performance thresholds.
Module 7: Security and Performance Trade-offs
- Measure the performance impact of field- and document-level security on query execution and caching efficiency.
- Optimize role-based access control by minimizing the number of roles per user and avoiding overly broad privileges.
- Enable TLS for internode and client communication while tuning cipher suites to reduce handshake overhead.
- Balance audit log verbosity to capture security events without overwhelming indexing capacity.
- Use API keys instead of long-lived tokens to reduce authentication overhead in high-frequency data ingestion scenarios.
- Cache frequently accessed security roles and user metadata to reduce reliance on external identity providers.
Module 8: Advanced Caching and Storage Optimization
- Configure index buffer sizes to maximize the use of available heap for indexing without starving query caches.
- Tune shard request cache settings based on query repetition rates and result size to improve hit ratios.
- Use frozen indices for historical data access patterns that tolerate higher latency in exchange for reduced memory footprint.
- Evaluate the use of SSDs versus HDDs for data tiers based on IOPS requirements and cost per GB for long-term retention.
- Implement forcemerge operations during off-peak hours on read-only indices to reduce segment count and improve search speed.
- Monitor and clear query cache entries selectively when cache bloat leads to excessive memory pressure on nodes.