Which one replaces the namenode of Hadoop in Map R? Is it CLDB?
Yes, MapR uses the CLDB (Container Location Database) instead of a NameNode. It's important to realize that the CLDB is not just a direct replacement for the NameNode - the MapR architecture distributes metadata across the cluster, rather than having all of the metadata on the NameNode. This has several advantages, including improved performance, support for more files and directories, and elimination of a single point of failure.
So while the CLDB replaces the NameNode and serves the same function - it is architecturally very different.
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