Critical Description
The BasicDataSource should have the "softMinEvictableIdleTimeMillis" (get and set) as the GenericObjectPool, to avoid destroying idle connections below the "minIdle" value. In this case, connections are dropped and immediately recreated with no reason. The "minEvictableIdleTimeMillis" should not be considered because there are ways to validate idle connections before they are used.
The class should have these lines of code, besides those existing:
// property
private long softMinEvictableIdleTimeMillis = GenericObjectPool.DEFAULT_SOFT_MIN_EVICTABLE_IDLE_TIME_MILLIS;
// getter
/**
- Returns the
{@link #softMinEvictableIdleTimeMillis} property.
* @return the value of the {@link #softMinEvictableIdleTimeMillis}property
- @see #softMinEvictableIdleTimeMillis
*/
public synchronized long getSoftMinEvictableIdleTimeMillis() { return softMinEvictableIdleTimeMillis; }
// setter
/**
- Sets the
{@link #softMinEvictableIdleTimeMillis}
property.
- @param softMinEvictableIdleTimeMillis the minimum amount of time an object
- may sit idle in the pool
- @see #softMinEvictableIdleTimeMillis
*/
public synchronized void setSoftMinEvictableIdleTimeMillis(final long softMinEvictableIdleTimeMillis)Unknown macro: { this.softMinEvictableIdleTimeMillis = softMinEvictableIdleTimeMillis; if (connectionPool != null) { connectionPool.setSoftMinEvictableIdleTimeMillis(softMinEvictableIdleTimeMillis); } }
// creator of the pool
@Override protected void createConnectionPool()
I implemented myself a "NotSoBasicDataSource" class, inheriting from "BasicDataSource" and used it in a single test. It worked: idle connections do not decrease under (and re-grow to) "minIdle".
Please, consider this feature, because it can save resources.
I don't know what is the behavior of the Tomcat DBCP, but it seems to me it has the same problem.
I'm waiting your opinions.