Partitioning data in HDFS improves processing efficiency by enhancing data locality. This means that computation is performed on nodes where the data is already stored, reducing the need for extensive data movement across the network and thereby improving overall processing speed.

Snapshot recovery techniques in Hadoop allow for the restoration of data to a specific point in time. Snapshots capture the state of the HDFS at a particular moment, providing a reliable way to recover data to a known and consistent state.

Apache Hive is primarily used for building data pipelines involving SQL-like queries in the Hadoop ecosystem. It provides a high-level query language, HiveQL, that allows users to express queries in a SQL-like syntax, making it easier for SQL users to work with Hadoop data.

Apache Storm distinguishes itself in the Hadoop ecosystem by specializing in stream processing. It is designed to handle real-time data streaming and enables the processing of data as it arrives, making it suitable for applications that require low-latency and continuous data processing.

Ambari plays a critical role in managing and monitoring Hadoop clusters. It provides an intuitive web-based interface for administrators to configure, manage, and monitor Hadoop services, ensuring the health and performance of the entire cluster.

In Hadoop, the traditional framework used for batch processing is Apache Hadoop MapReduce. It is a programming model and processing engine that enables the processing of large datasets in parallel across a distributed cluster.

Mockito is a common Java mocking framework used in unit testing Hadoop applications. It enables developers to create mock objects for HDFS and MapReduce functionalities, allowing for isolated testing of individual components without relying on a full Hadoop cluster.

The Shuffle function in Spark is critical for performing wide transformations like groupBy. It involves redistributing and exchanging data across the partitions, typically occurring during operations that require data to be grouped or aggregated across the cluster.

MRUnit tests can be written in Java to simulate the MapReduce environment. MRUnit is a testing framework for Apache Hadoop MapReduce jobs, allowing developers to write unit tests for their MapReduce programs.

In the case of a security breach, reviewing and tightening access controls is crucial. This involves restricting access privileges, ensuring least privilege principles, and regularly auditing and updating access permissions to minimize the risk of unauthorized access and data breaches.