[server] Make connection pooler configurable and set better default values
Drop the configuration connections-pool-size and add new configurations options:
* connections-pool-min-size. Set to 0 by default so we open connections only
when needed. This avoid opening min-size*processes connections at startup,
which is, it think, a good default.
* connections-pool-max-size. Set to 0 (unlimited) by default, so we move the
bottleneck to postgresql.
* connections-idle-timeout. Set to 10 minutes. I don't have arguments about
this except that this is the default in pgbouncer.
Latest changes
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* table of `all latest changes`_
Links below is providing useful RQL query example.
.. _all latest changes: ../view?rql=Any+M%2CX+WHERE+X+modification_date+M+ORDERBY+M+DESC+LIMIT+30