This article explains the concept of Power over Ethernet (PoE), why it is needed, its advantages, the roles of power‑sourcing and powered devices, power delivery modes, negotiation processes, IEEE standards (802.3af/at/bt), and the types of equipment that can support PoE.
This article demonstrates how to simulate and recover TiKV cluster failures by shutting down one, two, or three nodes, explains the impact on Raft groups and region availability, and provides step‑by‑step commands for disabling PD scheduling, using tikv‑ctl, and restoring data integrity.
This article walks through a real‑world TiDB PD cluster outage, explains how to diagnose the failure, retrieve necessary IDs, install and use the pd‑recover tool, and finally restore the cluster to a healthy state with detailed commands and screenshots.
TiDB is a distributed, MySQL-compatible database built from three core components—TiDB Server for stateless SQL processing, PD for global scheduling and metadata management, and TiKV for high‑performance key‑value storage—coordinated via the Raft consensus algorithm to ensure strong consistency and fault tolerance.
Power over Ethernet (PoE) enables simultaneous data transmission and DC power delivery over Ethernet cables, detailing its necessity, operation modes, negotiation processes, IEEE standards (802.3af/at/bt), TLV structures, and the types of devices that can act as power sources or powered endpoints.
This article explains the core components of TiDB—including TiKV Server, PD Server, and TiDB Server—their roles in storage, scheduling, and computation, and how the Raft consensus algorithm and TiSpark extension enable a reliable, scalable distributed database solution.
