How does HBase determine the number of pre-split regions?

There are several ways to determine the number of pre-split regions in HBase.

1. Manually specify: It is possible to manually specify the number of pre-split regions when creating an HBase table. When using the create command, you can include the SPLITS option to specify the number of pre-split regions.
2. By default, HBase will automatically select an appropriate default value for the number of pre-splits based on factors such as the number of RegionServers in the cluster and the estimated size of the HBase table if no manual pre-partitioning is specified.
3. Automatic splitting: HBase also offers an automatic splitting method to determine the number of pre-partitions. The split command can be used to perform splitting operations on an existing table. HBase will determine the splitting points based on the distribution of data and factors like load balancing, ultimately deciding the number of pre-partitions.

It is important to note that the selection of the number of pre-partitions has a certain impact on the performance and load balancing of HBase. Too few pre-partitions may cause data skew and load imbalance, while too many pre-partitions will increase the management and maintenance costs of HBase. Therefore, when determining the number of pre-partitions, factors such as the scale of the cluster, the size of the table, and the distribution of data should be comprehensively considered.