It's challenging to troubleshoot issues in a distributed database because the information about the system is scattered in different machines.
TiDB is an open-source, distributed SQL database that supports Hybrid Transactional/Analytical Processing (HTAP) workloads. Before version 4.0, it could be difficult to efficiently troubleshoot TiDB's system problems. To diagnose a TiDB cluster's issues, even an experienced database administrator (DBA) needed to understand TiDB's basic architecture, get familiar with thousands of TiDB monitoring metrics, and gain experience in the field to ensure that when they encountered similar problems next time, they could fix them more quickly.