> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/server/ha-and-performance/optimization-and-tuning/buffers-caches-and-threads/thread-pool.md).

# Thread Pool

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[Thread Pool in MariaDB](/docs/server/ha-and-performance/optimization-and-tuning/buffers-caches-and-threads/thread-pool/thread-pool-in-mariadb.md)
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Explains MariaDB's dynamic, adaptive thread pool: the problems it solves, its features, when it helps or hurts, and how to configure it via thread\_handling and related system variables.
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[Thread Groups in the Unix Implementation of the Thread Pool](/docs/server/ha-and-performance/optimization-and-tuning/buffers-caches-and-threads/thread-pool/thread-groups-in-the-unix-implementation-of-the-thread-pool.md)
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Describes thread groups in the Unix thread pool implementation, how thread\_pool\_size sets their number, and how client connections are distributed among them.
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[Thread Pool System and Status Variables](/docs/server/ha-and-performance/optimization-and-tuning/buffers-caches-and-threads/thread-pool/thread-pool-system-status-variables.md)
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Documents the system and status variables used to configure and monitor the MariaDB thread pool, including extra\_max\_connections, extra\_port, and thread\_handling.
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[Thread Pool in MariaDB 5.1 - 5.3](/docs/server/ha-and-performance/optimization-and-tuning/buffers-caches-and-threads/thread-pool/thread-pool-in-mariadb-51-53.md)
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Documents the old pool-of-threads implementation in MariaDB up to version 5.3, retained for reference by older compatibility pages.
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