[1] Due to its connection to slavery, the terminology is a subject of controversy and has been replaced with alternative terms in some cases.
A serial peripheral interface (SPI) bus typically has a single master controlling multiple slaves.
These databases are used in scenarios where performance is an acceptable tradeoff for ACID properties, for example non mission critical data, like suggesting similar purchases.
In 2020, Paul Vixie commented on his choice of words: I introduced the master/slave terminology in RFC 2136, because I needed names for the roles in an AXFR/IXFR transaction, and the zone transfer hierarchy could be more than one layer deep, such that a server might initiate some AXFR/IXFR's to the "primary master" but then respond to AXFR/IXFR's from other servers.
[15] The Black Lives Matter movement in the United States sparked renewed discussion, and terminology changes occurred in 2020.
[17][3] None-the-less, various alternate and generally context sensitive terms have been proposed including:[16][3][18][19][20][21][22][23][24][25] In 2003, after receiving a discrimination complaint from a county employee, the County of Los Angeles in California asked that manufacturers, suppliers and contractors stop using master and slave terminology on products.
[4] Python switched to main, parent, and server; and worker, child, and helper, depending on context.
[4][28] The Linux kernel adopted a similar policy to use more specific terms in new code and documentation.
[19][29] In July 2018, Google's developer style guide was updated to include avoiding the term master in software documentation, especially in combination with slave.