Heartbeat, ELK Stack
Heartbeat: A heartbeat in distributed systems is a periodic signal or message sent by a node or component to inform others of its operational status and health.
Purpose:
- Liveness Monitoring: Heartbeats help detect if a node or process is alive and responsive. If heartbeats stop, it may indicate a failure.
- Failure Detection: They are crucial for timely identification of node failures or network partitions.
- Load Balancing: In load balancing scenarios, heartbeats can be used to distribute incoming requests efficiently.
- Resource Allocation: Heartbeats may convey information about resource availability or utilization.
How it Works:
- Nodes or processes periodically send heartbeat signals/messages to a central coordinator or to one another.
- If a node stops sending heartbeats within a predefined time (timeout), it is considered unavailable or failed.
- Failure detection mechanisms can trigger actions like node recovery, redistribution of work, or raising alerts.
ELK Stack:
Elasticsearch:
- Purpose: A distributed, RESTful search and analytics engine designed for horizontal scalability and real-time search.
- Use Cases: Storing, searching, and analyzing large volumes of data, such as logs, metrics, and application-generated data.
- Features: Full-text search, Fuzzy search, schema-free JSON documents, near real-time indexing, and extensive querying capabilities.
Logstash:
- Purpose: A server-side data processing pipeline that ingests data from multiple sources, transforms it, and sends it to Elasticsearch.
- Use Cases: Data ingestion, transformation, and enrichment for logs, metrics, and other events.
- Features: Numerous input, filter, and output plugins for handling diverse data formats and sources.
Kibana:
- Purpose: A web-based visualization and exploration tool for Elasticsearch data.
- Use Cases: Creating dashboards, visualizations, and exploring data stored in Elasticsearch.
- Features: Graphical representation of data, real-time monitoring, and user-friendly dashboards.
Workflow:
- Ingest: Logstash ingests data from various sources, applies filters, and processes it.
- Store: Processed data is stored in Elasticsearch, which can handle large-scale data storage and querying.
- Visualize: Kibana provides a user interface to create visualizations and dashboards for data exploration.