Using database.connectionPool with MySQL

[Neil Leathers]

I see in the documentation for database.connectionPool the statement: "Default is false for MySQL, and true for other database backends". Why is this the case? Is the connectionPool unstable with MySQL? Do I need to configure something special in MySQL (or Gerrit) to handle this? Are there any caveats or tuning issues I need to be aware of if I turn this on?

Neil Leathers

[Shawn Pearce]

I wrote this because IIRC MySQL was having trouble keeping the
connections open in the pool. Connections would be returned, closed by
the server, and then not work anymore. Disabling the pool was safer as
it allowed connections to be closed after use and reopened the next
time one is demanded.

MySQL on localhost can open/close connections much faster than
PostgreSQL can. There is lower overhead for the open/close part of the
connection, so the impact of the pool vs. no pool is less noticeable
on MySQL.