What is the process of writing data in HBase?

9 months ago

Olivia Parker

2 minutes

The process of writing data in HBase can be divided into the following steps:

The client sends a write request to the HMaster: When the client needs to write data to HBase, it first sends a write request to the HMaster, specifying the table name and row key for the write.
HMaster searches for RegionServer: After receiving a write request, HMaster will locate the corresponding RegionServer based on the table name and row key, and forward the write request to that RegionServer.
When a RegionServer receives a write request, once the target RegionServer is found, it will receive the write request and write the data into the MemStore in memory.
When the data in the MemStore reaches a certain size, HBase triggers a flush operation to write the data from the MemStore to an HFile (storage file in HBase) and persist it in HDFS.
Update WAL log: Before writing data to disk, HBase first writes the data to a WAL (Write-Ahead Logging) log to ensure data reliability. In the event of a failure during the disk writing process, data can be recovered using the WAL log.
The write result is returned: Once the data is successfully written to the disk and the WAL log is updated, the RegionServer will return the successful write result to the client.

In general, the data writing process of HBase involves first writing data to the memory in MemStore, then periodically flushing the data from MemStore to the disk in HFile, while ensuring data reliability through WAL logs.