Hadoop 1.x has many limitations or drawbacks. Main drawback of Hadoop 1.x is that MapReduce Component in it’s Architecture. That means it supports only MapReduce-based Batch/Data Processing Applications.
Hadoop 1.x has the following Limitations/Drawbacks:
- Only one NameNode is possible to configure i.e If NameNode fails entire cluster goes down, that is why NameNode is called as Single Point of Failure (SPOF)
- Secondary NameNode was just to take hourly backup of MetaData from NameNode.
- Lets say SecondaryNameNode has taken backup at 10:00 AM, 10:45 NameNode fails then the transaction done during 10:00 to 10:45 is gone.
- It is only suitable for Batch Processing of Huge amount of Data, which is already in Hadoop System.
- It is not suitable for Real-time Data Processing.
- It supports upto 4000 Nodes per Cluster.
- It has a single component : JobTracker to perform many activities like Resource Management, Job Scheduling, Job Monitoring, Re-scheduling Jobs etc.
- JobTracker is the single point of failure.
- It supports only one Name Node and One Namespace per Cluster.
- It does not support Horizontal Scalability of NameNode.
- It runs only Map/Reduce jobs..