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MySQL thread cache

Yusuf Goolamabbas asked me:

Arjen, The mysql 5.0 datasheet refers “server side thread pool” as a 5.0 feature. Could you elaborate on this in a blog post. Does this imply that solutions like sqlrelay SQL Relay are not needed for connection pooling in 5.0 ?

Here’s the post, Yusuf!

All versions of MySQL Server have a thread cache (tunable with thread_cache_size). Currently, connection to the server runs in its own thread. Creating a thread costs time, so rather than killing the thread when a connection closes, the server can keep the thread in its thread cache, so it can be used for new connection later. A very handy feature, but it has nothing to do with connection pooling.

There is definitely a use for tools like SQL Relay, also with MySQL 5.0

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