Apache Hama is a distributed computing framework based on

bulk synchronous parallel The bulk synchronous parallel (BSP) abstract computer is a bridging model for designing parallel algorithms. It is similar to the parallel random access machine (PRAM) model, but unlike PRAM, BSP does not take communication and synchronization ...

computing techniques for massive scientific computations e.g.,

matrix Matrix (: matrices or matrixes) or MATRIX may refer to: Science and mathematics * Matrix (mathematics), a rectangular array of numbers, symbols or expressions * Matrix (logic), part of a formula in prenex normal form * Matrix (biology), the m ...

, and algorithms. Originally a sub-project of

Hadoop Apache Hadoop () is a collection of Open-source software, open-source software utilities for reliable, scalable, distributed computing. It provides a software framework for Clustered file system, distributed storage and processing of big data usin ...

, it became an

Apache Software Foundation The Apache Software Foundation ( ; ASF) is an American nonprofit corporation (classified as a 501(c)(3) organization in the United States) to support a number of open-source software projects. The ASF was formed from a group of developers of the ...

top level project in 2012. It was created by Edward J. Yoon, who named it (short for "Hadoop Matrix Algebra"), and Hama also means

hippopotamus The hippopotamus (''Hippopotamus amphibius;'' ; : hippopotamuses), often shortened to hippo (: hippos), further qualified as the common hippopotamus, Nile hippopotamus and river hippopotamus, is a large semiaquatic mammal native to sub-Sahar ...

in Yoon's native Korean language (하마), following the trend of naming Apache projects after animals and zoology (such as

Apache Pig Apache Pig is a high-level platform for creating programs that run on Hadoop, Apache Hadoop. The language for this platform is called Pig Latin. Pig can execute its Hadoop jobs in MapReduce, Apache Tez, or Apache Spark. Pig Latin abstracts the ...

). Hama was inspired by

Google Google LLC (, ) is an American multinational corporation and technology company focusing on online advertising, search engine technology, cloud computing, computer software, quantum computing, e-commerce, consumer electronics, and artificial ...

's Pregel large-scale graph computing framework described in 2010. When executing graph algorithms, Hama showed a fifty-fold performance increase relative to Hadoop. Retired in April 2020, project resources are made available as part of the Apache Attic. Yoon cited issues of installation,

scalability Scalability is the property of a system to handle a growing amount of work. One definition for software systems specifies that this may be done by adding resources to the system. In an economic context, a scalable business model implies that ...

, and a difficult

programming model A programming model is an execution model coupled to an API or a particular pattern of code. In this style, there are actually two execution models in play: the execution model of the base programming language and the execution model of the p ...

for its lack of adoption.

Architecture

Hama consists of three major components: BSPMaster, GroomServers and Zookeeper.Apache Hama Architecture
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BSPMaster

BSPMaster is responsible for: * Maintaining groom server status * Controlling super steps in a cluster * Maintaining job progress information * Scheduling jobs and assigning tasks to groom servers * Disseminating execution class across groom servers * Controlling fault * Providing users with the cluster control interface. A BSP Master and multiple grooms are started by the script. Then, the bsp master starts up with a RPC server for groom servers. Groom servers starts up with a BSPPeer instance and a RPC proxy to contact the bsp master. After started, each groom periodically sends a heartbeat message that encloses its groom server status, including maximum task capacity, unused memory, and so on. Each time the BSP master receives a heartbeat message, it brings up-to-date groom server status - the bsp master makes use of groom servers' status in order to effectively assign tasks to idle groom servers - and returns a heartbeat response that contains assigned tasks and others actions that a groom server has to do. For now, we have a FIFO job scheduler and very simple task assignment algorithms.

GroomServer

A groom server (shortly referred to as groom) is a process that performs BSP tasks assigned by BSPMaster. Each groom contacts the BSPMaster, and it takes assigned tasks and reports its status by means of periodical piggybacks with BSPMaster. Each groom is designed to run with HDFS or other distributed storages. Basically, a groom server and a data node should be run on one physical node.

Zookeeper

A Zookeeper is used to manage the efficient barrier synchronisation of the BSPPeers.

References

External links

Apache Hama WebsiteApache Hama blog
{{Apache Software Foundation

Hama Hama ( ', ) is a city on the banks of the Orontes River in west-central Syria. It is located north of Damascus and north of Homs. It is the provincial capital of the Hama Governorate. With a population of 996,000 (2023 census), Hama is one o ...