move the connection pool settings for sql drivers back. new settings were...

move the connection pool settings for sql drivers back.  new settings were making things worse regarding proliferation of unused connections.

src/metabase/driver/generic_sql.clj

@@ -97,12 +97,12 @@
   (memoize/ttl
    (fn [spec]
      (log/debug (u/format-color 'magenta "Creating new connection pool..."))
-     (kdb/connection-pool (assoc spec :minimum-pool-size           3
+     (kdb/connection-pool (assoc spec :minimum-pool-size           1
                                       ;; prevent broken connections closed by dbs by testing them every 3 mins
                                       :idle-connection-test-period (* 3 60)
                                       ;; prevent overly large pools by condensing them when connections are idle for 15m+
                                       :excess-timeout              (* 15 60))))
-   :ttl/threshold (* 60 60 1000)))
+   :ttl/threshold (* 6 60 60 1000)))
 
 (defn db->jdbc-connection-spec
   "Return a JDBC connection spec for DATABASE. Normally this will have a C3P0 pool as its datasource, unless the database is `short-lived`."