What Are the Differences Between Online and Offline Patch Installation of GeminiDB Redis Nodes? How Long Will the Upgrades Take? What Are the Impacts on Services?

• Online patch installation: Nodes are upgraded in rolling mode. The upgrade duration is positively related to the number of nodes. Each node takes about 2 to 5 minutes. Both primary/standby and cluster instances contain three internal management nodes, which are upgraded at the same time. For example, a GeminiDB Redis instance consists of six nodes, including three worker nodes and three internal management nodes. The online upgrade takes about 12 to 30 minutes. During the upgrade of a single node, services are affected due to a few seconds of jitter. Therefore, a reconnection mechanism is required. You are advised to upgrade the node during off-peak hours and keep the CPU and memory usage at a low level. This prevents exceptions such as heavy load on other nodes and process startup failures.
• Offline patch installation: All nodes are upgraded concurrently. During the upgrade, services are interrupted for about 10 to 20 minutes. Offline upgrade is applicable when services are stopped or no service is accessed. Exercise caution when performing this operation.

For details about how to install the patch of GeminiDB Redis API, see Upgrading a Minor Version.