dovecot-2.1: lib-sql: Connect to all configured hosts immediately.

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.1/rev/55552b4e8c65
changeset: 13493:55552b4e8c65
user:      Timo Sirainen <tss at iki.fi>
date:      Thu Sep 15 13:47:44 2011 +0300
description:
lib-sql: Connect to all configured hosts immediately.
This makes load balancing between them actually work always.

diffstat:

 src/lib-sql/driver-sqlpool.c |  17 +++++++++++++++--
 1 files changed, 15 insertions(+), 2 deletions(-)

diffs (34 lines):

diff -r 1b829680dce4 -r 55552b4e8c65 src/lib-sql/driver-sqlpool.c
--- a/src/lib-sql/driver-sqlpool.c	Thu Sep 15 13:46:45 2011 +0300
+++ b/src/lib-sql/driver-sqlpool.c	Thu Sep 15 13:47:44 2011 +0300
@@ -447,6 +447,19 @@
 		db->connection_limit = SQL_DEFAULT_CONNECTION_LIMIT;
 }
 
+static void sqlpool_add_all_once(struct sqlpool_db *db)
+{
+	struct sqlpool_host *host;
+	unsigned int host_idx;
+
+	for (;;) {
+		host = sqlpool_find_host_with_least_connections(db, &host_idx);
+		if (host->connection_count > 0)
+			break;
+		(void)sqlpool_add_connection(db, host, host_idx);
+	}
+}
+
 struct sql_db *
 driver_sqlpool_init(const char *connect_string, const struct sql_db *driver)
 {
@@ -465,8 +478,8 @@
 	} T_END;
 
 	i_array_init(&db->all_connections, 16);
-	/* always have at least one backend connection initialized */
-	(void)sqlpool_add_new_connection(db);
+	/* connect to all databases so we can do load balancing immediately */
+	sqlpool_add_all_once(db);
 	return &db->api;
 }