Hive Metastore in embedded mode
A key component of Hive is its metastore, which stores metadata about the structure of the data. Understanding whether this metastore can be shared among multiple users in an embedded mode is crucial for effective Hive implementation. This article explores the possibilities and limitations of such a setup.
What is Embedded Hive Metastore?
In embedded mode, Hive uses Apache Derby as its default metastore database. It runs in the same process as the Hive service and is generally used for lightweight tasks and single-user environments.
Limitations of Embedded Metastore for multi-user access
- Single-User Design: Apache Derby, in its embedded mode, is designed primarily for single-user access. This means it can be accessed by only one JVM at a time, limiting its use in a multi-user environment.
- Concurrency Issues: When multiple users try to access the metastore simultaneously in embedded mode, it can lead to concurrency issues and access conflicts.
- Data Integrity Risks: Multiple accesses to the same embedded metastore increase the risk of data corruption and inconsistency.
Can Multiple users share the Metastore in embedded Mode?
Answer: Not Recommended
While it’s technically possible to configure multiple users to point to the same embedded metastore, it’s not recommended due to the limitations mentioned above. This setup can lead to significant challenges in terms of stability, concurrency, and data integrity.
Best practices for Multi-User environments
For environments where multiple users need to access Hive, it’s advisable to use a standalone metastore setup. This involves configuring Hive to use an external database like MySQL or PostgreSQL as its metastore.
Advantages of Standalone Metastore:
- Concurrent Access: Supports multiple users accessing the metastore simultaneously without conflicts.
- Scalability and Stability: More robust and capable of handling larger, more complex environments.
- Data Integrity: Reduces the risk of metastore corruption and ensures metadata consistency.
Hive important pages to refer
