Fix autodb cleanup

Old cleanup code was mixing up databases and pools
- as soon as one empty pool was found, the database
was tagged as 'idle', potentially later killing database
with active users.

Change the code to tag database as active when active
pool is found and later checking for inactive databases.

Reported-By: Hubert Depesz Lubaczewski

2 files changed, 22 insertions, 4 deletions

diff --git a/include/bouncer.h b/include/bouncer.h
index 77eb3b2..df84fa8 100644
--- a/include/bouncer.h
+++ b/include/bouncer.h
@@ -269,7 +269,8 @@ struct PgDatabase {
 	/* startup commands to send to server after connect. malloc-ed */
 	const char *connect_query;
 
-	usec_t inactive_time; /* when auto-database became inactive (to kill it after timeout) */
+	usec_t inactive_time;	/* when auto-database became inactive (to kill it after timeout) */
+	unsigned active_stamp;	/* set if autodb has connections */
 };
 
 
diff --git a/src/janitor.c b/src/janitor.c
index bed166d..ea964fa 100644
--- a/src/janitor.c
+++ b/src/janitor.c
@@ -502,6 +502,7 @@ static void cleanup_inactive_autodatabases(void)
 	if (cf_autodb_idle_timeout <= 0)
 		return;
 
+	/* now kill the old ones */
 	statlist_for_each_safe(item, &autodatabase_idle_list, tmp) {
 		db = container_of(item, PgDatabase, head);
 		age = now - db->inactive_time;
@@ -517,6 +518,10 @@ static void do_full_maint(int sock, short flags, void *arg)
 {
 	struct List *item, *tmp;
 	PgPool *pool;
+	PgDatabase *db;
+
+	static unsigned int seq;
+	seq++;
 
 	/*
 	 * Avoid doing anything that may surprise other pgbouncer.
@@ -530,9 +535,21 @@ static void do_full_maint(int sock, short flags, void *arg)
 			continue;
 		pool_server_maint(pool);
 		pool_client_maint(pool);
-		if (pool->db->db_auto && pool->db->inactive_time == 0 &&
-				pool_client_count(pool) == 0 && pool_server_count(pool) == 0 ) {
-			pool->db->inactive_time = get_cached_time();
+
+		/* is autodb active? */
+		if (pool->db->db_auto && pool->db->inactive_time == 0) {
+			if (pool_client_count(pool) > 0 || pool_server_count(pool) > 0)
+				pool->db->active_stamp = seq;
+		}
+	}
+
+	/* find inactive autodbs */
+	statlist_for_each_safe(item, &database_list, tmp) {
+		db = container_of(item, PgDatabase, head);
+		if (db->db_auto && db->inactive_time == 0) {
+			if (db->active_stamp == seq)
+				continue;
+			db->inactive_time = get_cached_time();
 			statlist_remove(&database_list, &pool->db->head);
 			statlist_append(&autodatabase_idle_list, &pool->db->head);
 		}