acquireRetryAttempts-->新コレクションを取得するのに失敗したときのリトライ回数
acquireRetryDelay-->リトライ間隔時間
autoCommitOnClose-->名前通り
automaticTestTable
breakAfterAcquireFailureーー＞一回失敗したら、閉鎖して試しない。
checkoutTimeoutーー＞プールが使い尽くされている場合のコレクションの最大待つ時間。タイムアウト時SQLExceptionが投げる
idleConnectionTestPeriodー＞接続プール内のアイドル状態のコレクションを時間間隔「0以外の数字」でチェックする
initialPoolSize
maxPoolSize
minPoolSize
maxConnectionAge
numHelperThreads
★c3p0.idle_test_period、hibernate.c3p0.timeout、hibernate.c3p0.min_size
The database server may close a connection on
its side after a certain amount of time - causing some error in your
application, because it'll attempt to send a query on a connection which
is no longer available on the server side.
In order to avoid this you can let the pool periodically check a connection (Think of a ping) for it's validity. This is what
In order to avoid this you can let the pool periodically check a connection (Think of a ping) for it's validity. This is what
idle_test_period is for. timeout is the timespan after which the pool will remove
a connection from the pool, because the connection wasn't checked out
(used) for a while and the pool contains more connections than c3pO.min_size.