Hadoop – Cluster installation (high availability)


HDFS file more and more to do HDFS – four roles of HDFS HDFS – a high availability NameNode HDFS – what is safe mode HDFS – the NameNode how to perceive the DataNode HDFS – what is the metadata HDFS – How does the double caching mechanism guarantee high concurrent requests to metadata How does the HDFS-Checkpoint mechanism implement HDFS-all those things about writing data

HDFS source mind map

NameNode Start DataNode Start Metadata Management – Client Metadata Management – Server Metadata Management – Standby Reading JournalNode Metadata Management – Checkpoint Write Process – Create Write Process – Write Process Write data flow-queue processing Write data flow-DataNode processing