Cluster Deployment Overview

KWDB supports the following cluster deployment types:

Category	Multi-Replica Cluster	Single-Replica Cluster
Definition	KWDB runs on multiple nodes within the same data center. Each data range has 3 replicas by default, distributed across different nodes.	KWDB runs on multiple nodes within the same data center. Each data range has only one replica; all data storage and update operations are handled by that single replica.
Performance	- Writes: Lower than single node and single-replica clusters - Reads: • Simple queries: slightly lower than single node • Complex queries: same as single-replica clusters Tip: You can optimize write performance with the following parameters: - ts.raft_log.sync_period: Extends the disk flush cycle for time-series data raft logs - ts.raftlog_combine_wal.enabled: Enables merging of time-series data raft logs and WAL For more information, see Cluster Parameters. Note: After enabling these optimizations, unflushed data may be lost if a node crashes unexpectedly.	- Writes: Higher than multi-replica clusters but slightly lower than single node - Reads: • Simple queries: slightly lower than single node • Complex queries: same as multi-replica clusters
Cluster Scaling	Supports cluster scale-out and scale-in. For more information, see Cluster Scaling.	Supports only cluster scale-out. For more information, see Cluster Scaling.
High Availability	Supports high availability with automatic failover and strong data consistency. For more information, see Cluster High Availability. Note: After extending the disk flush cycle for time-series data raft logs, unflushed data may be lost if a node crashes unexpectedly.	- Does not support high availability. - When cluster nodes fail, write operations, queries, and DDL statements may fail. - When the number of failed nodes exceeds half of the total nodes, all operations will be suspended.
Data Balancing	Supports automatic data balancing after scaling operations.	Does not support automatic data balancing after scaling out the cluster.

single-node deployment differs slightly from cluster deployment. For more information, see Single-node Deployment.

This section includes the following documents:

• Deployment Workflow
• Preparation
  • Prepare for Bare-Metal Deployment
  • Prepare for Container Deployment
• Cluster Deployment
  • Deploy Using Scripts
  • Deploy Using kwbase CLI
  • Deploy Using Docker Run Command
• Cluster Configuration
  • Create Users
  • Configure Cluster Settings
    • Bare-Metal Deployment
    • Container Deployment
• Cluster Management
  • Start and Stop KWDB Service
  • Uninstall Clusters