#elasticsearch

Build centralized logging with ELK stack (Elasticsearch, Logstash, Kibana). Pipeline: 1. Filebeat agents on application servers. 2. Logstash for log parsing and enrichment. 3. Elasticsearch cluster for storage and indexing. 4. Kibana for visualization and search. 5. Index lifecycle management for retention. 6. Alerting on error patterns. 7. Log correlation across services. Use structured logging (JSON). Include security (authentication, encryption) and performance tuning (sharding, replicas).

Implement centralized logging with ELK Stack (Elasticsearch, Logstash, Kibana) for comprehensive log analysis and troubleshooting. ELK Stack architecture: 1. Elasticsearch: distributed search engine, 3-node cluster minimum, data replication factor 1. 2. Logstash: log processing pipeline, input plugins, filters, output destinations. 3. Kibana: data visualization, dashboard creation, alerting, user authentication. 4. Beats: lightweight data shippers (Filebeat, Metricbeat, Packetbeat, Auditbeat). Log collection strategy: 1. Application logs: structured JSON logging, log levels (DEBUG, INFO, WARN, ERROR), correlation IDs. 2. System logs: syslog collection, OS metrics, service status, security events. 3. Infrastructure logs: load balancer access logs, database query logs, container logs. Data lifecycle management: 1. Index management: daily indices, rollover based on size (50GB) or age (1 day). 2. Retention policies: hot (7 days), warm (30 days), cold (90 days), delete after 1 year. 3. Storage optimization: compression, field exclusion, index patterns. Security and access control: 1. X-Pack Security: role-based access, field-level security, audit logging. 2. Encryption: TLS for data in transit, encryption at rest for sensitive data. Monitoring and alerting: 1. Performance metrics: indexing rate (target 10k docs/sec), query response time (<1s). 2. Cluster health: green/yellow/red status monitoring, shard allocation, disk usage. Alert configuration: Watcher for threshold-based alerts, Slack/email notifications, escalation procedures for critical events.