Developer(s) | Apache Software Foundation |
---|---|
Stable release | 2.0.1 (December 24, 2020 [1] ) [±] |
Repository | Accumulo Repository |
Written in | Java |
Operating system | Cross-platform |
License | Apache License 2.0 |
Website | accumulo |
Apache Accumulo is a highly scalable sorted, distributed key-value store based on Google's Bigtable. [2] It is a system built on top of Apache Hadoop, Apache ZooKeeper, and Apache Thrift. Written in Java, Accumulo has cell-level access labels and server-side programming mechanisms. According to DB-Engines ranking, Accumulo is the third most popular NoSQL wide column store behind Apache Cassandra and HBase and the 67th most popular database engine of any type (complete) as of 2018. [3]
Accumulo was created in 2008 by the US National Security Agency and contributed to the Apache Foundation as an incubator project in September 2011. [4]
On March 21, 2012, Accumulo graduated from incubation at Apache, making it a top-level project. [5]
In June 2012, the US Senate Armed Services Committee (SASC) released the Draft 2012 Department of Defense (DoD) Authorization Bill, which included references to Apache Accumulo. In the draft bill SASC required DoD to evaluate whether Apache Accumulo could achieve commercial viability before implementing it throughout DoD. [6] Specific criteria were not included in the draft language, but the establishment of commercial entities supporting Apache Accumulo could be considered a success factor. [7]
Apache Accumulo extends the Bigtable data model, adding a new element to the key called Column Visibility. This element stores a logical combination of security labels that must be satisfied at query time in order for the key and value to be returned as part of a user request. This allows data of varying security requirements to be stored in the same table, and allows users to see only those keys and values for which they are authorized. [4]
In addition to Cell-Level Security, Apache Accumulo provides a server-side programming mechanism called Iterators that allows users to perform additional processing at the Tablet Server. The range of operations that can be applied is equivalent to those that can be implemented within a MapReduce Combiner function, which produces an aggregate value for several key-value pairs.
Apache Accumulo orders entries in order of user keys, and exposes an iterator over a key range. This allows locality of reference not available from some other distributed stores (including Cassandra and Voldemort that order by hash of the user key).
Apache Hadoop is a collection of open-source software utilities that facilitates using a network of many computers to solve problems involving massive amounts of data and computation. It provides a software framework for distributed storage and processing of big data using the MapReduce programming model. Hadoop was originally designed for computer clusters built from commodity hardware, which is still the common use. It has since also found use on clusters of higher-end hardware. All the modules in Hadoop are designed with a fundamental assumption that hardware failures are common occurrences and should be automatically handled by the framework.
Bigtable is a fully managed wide-column and key-value NoSQL database service for large analytical and operational workloads as part of the Google Cloud portfolio.
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Cassandra is a free and open-source, distributed, wide-column store, NoSQL database management system designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure. Cassandra offers support for clusters spanning multiple datacenters, with asynchronous masterless replication allowing low latency operations for all clients. Cassandra was designed to implement a combination of Amazon's Dynamo distributed storage and replication techniques combined with Google's Bigtable data and storage engine model.
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Apache ZooKeeper is an open-source server for highly reliable distributed coordination of cloud applications. It is a project of the Apache Software Foundation.
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Apache Drill is an open-source software framework that supports data-intensive distributed applications for interactive analysis of large-scale datasets. Built chiefly by contributions from developers from MapR, Drill is inspired by Google's Dremel system, also productized as BigQuery. Drill is an Apache top-level project. Tom Shiran is the founder of the Apache Drill Project. It was designated an Apache Software Foundation top-level project in December 2016.
Sqoop is a command-line interface application for transferring data between relational databases and Hadoop.
In computer science, the log-structured merge-tree is a data structure with performance characteristics that make it attractive for providing indexed access to files with high insert volume, such as transactional log data. LSM trees, like other search trees, maintain key-value pairs. LSM trees maintain data in two or more separate structures, each of which is optimized for its respective underlying storage medium; data is synchronized between the two structures efficiently, in batches.
Apache Trafodion is an open-source Top-Level Project at the Apache Software Foundation. It was originally developed by the information technology division of Hewlett-Packard Company and HP Labs to provide the SQL query language on Apache HBase targeting big data transactional or operational workloads. The project was named after the Welsh word for transactions. As of April 2021, it is no longer actively developed.
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