From: Marko Kreen <markokr@gmail.com>
Date: Wed, 13 Jun 2007 21:08:29 +0000 (+0000)
Subject: pause/resume specific database
X-Git-Tag: pgbouncer_1_0_8~4
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d61d3e4cd07222ce89923b153f64686727347791;p=pgbouncer

pause/resume specific database
---

diff --git a/src/admin.c b/src/admin.c
index b6822c4..f116192 100644
--- a/src/admin.c
+++ b/src/admin.c
@@ -86,6 +86,34 @@ bool admin_error(PgSocket *admin, const char *fmt, ...)
 	return res;
 }
 
+static int count_paused_databases(void)
+{
+	List *item;
+	PgDatabase *db;
+	int cnt = 0;
+
+	statlist_for_each(item, &database_list) {
+		db = container_of(item, PgDatabase, head);
+		cnt += db->db_paused;
+	}
+	return cnt;
+}
+
+static int count_db_active(PgDatabase *db)
+{
+	List *item;
+	PgPool *pool;
+	int cnt = 0;
+
+	statlist_for_each(item, &pool_list) {
+		pool = container_of(item, PgPool, head);
+		if (pool->db != db)
+			continue;
+		cnt += pool_server_count(pool);
+	}
+	return cnt;
+}
+
 void admin_flush(PgSocket *admin, PktBuf *buf, const char *desc)
 {
 	pktbuf_write_CommandComplete(buf, desc);
@@ -597,20 +625,31 @@ static bool admin_cmd_shutdown(PgSocket *admin, const char *arg)
 /* Command: RESUME */
 static bool admin_cmd_resume(PgSocket *admin, const char *arg)
 {
-	int tmp_mode = cf_pause_mode;
 	if (!admin->admin_user)
 		return admin_error(admin, "admin access needed");
 
-	log_info("RESUME command issued");
-	cf_pause_mode = P_NONE;
-	switch (tmp_mode) {
-	case P_SUSPEND:
-		resume_all();
-	case P_PAUSE:
-		return admin_ready(admin, "RESUME");
-	default:
-		return admin_error(admin, "Pooler is not paused/suspended");
+	if (!arg[0]) {
+		int tmp_mode = cf_pause_mode;
+		log_info("RESUME command issued");
+		cf_pause_mode = P_NONE;
+		switch (tmp_mode) {
+		case P_SUSPEND:
+			resume_all();
+		case P_PAUSE:
+			break;
+		default:
+			return admin_error(admin, "Pooler is not paused/suspended");
+		}
+	} else {
+		PgDatabase *db = find_database(arg);
+		log_info("PAUSE '%s' command issued", arg);
+		if (db == NULL)
+			return admin_error(admin, "no such database: %s", arg);
+		if (!db->db_paused)
+			return admin_error(admin, "database %s is not paused", arg);
+		db->db_paused = 0;
 	}
+	return admin_ready(admin, "RESUME");
 }
 
 /* Command: SUSPEND */
@@ -625,6 +664,10 @@ static bool admin_cmd_suspend(PgSocket *admin, const char *arg)
 	if (cf_pause_mode)
 		return admin_error(admin, "already suspended/paused");
 
+	/* suspend needs to be able to flush buffers */
+	if (count_paused_databases() > 0)
+		return admin_error(admin, "cannot suspend with paused databases");
+
 	log_info("SUSPEND command issued");
 	cf_pause_mode = P_SUSPEND;
 	admin->wait_for_response = 1;
@@ -642,9 +685,24 @@ static bool admin_cmd_pause(PgSocket *admin, const char *arg)
 	if (cf_pause_mode)
 		return admin_error(admin, "already suspended/paused");
 
-	log_info("PAUSE command issued");
-	cf_pause_mode = P_PAUSE;
-	admin->wait_for_response = 1;
+	if (!arg[0]) {
+		log_info("PAUSE command issued");
+		cf_pause_mode = P_PAUSE;
+		admin->wait_for_response = 1;
+	} else {
+		PgDatabase *db;
+		log_info("PAUSE '%s' command issued", arg);
+		db = find_database(arg);
+		if (db == NULL)
+			return admin_error(admin, "no such database: %s", arg);
+		if (db == admin->pool->db)
+			return admin_error(admin, "cannot pause admin db: %s", arg);
+		db->db_paused = 1;
+		if (count_db_active(db) > 0)
+			admin->wait_for_response = 1;
+		else
+			return admin_ready(admin, "PAUSE");
+	}
 
 	return true;
 }
@@ -937,7 +995,10 @@ void admin_pause_done(void)
 			admin_ready(admin, "SUSPEND");
 			break;
 		default:
-			fatal("admin_pause_done: bad state");
+			if (count_paused_databases() > 0)
+				admin_ready(admin, "PAUSE");
+			else
+				fatal("admin_pause_done: bad state");
 		}
 		admin->wait_for_response = 0;
 	}
diff --git a/src/bouncer.h b/src/bouncer.h
index f81598a..c586eb0 100644
--- a/src/bouncer.h
+++ b/src/bouncer.h
@@ -182,6 +182,8 @@ struct PgDatabase {
 	unsigned		welcome_msg_len;
 	unsigned		welcome_msg_ready:1;
 
+	unsigned		db_paused:1;
+
 	/* key/val pairs (without user) for startup msg to be sent to server */
 	uint8			startup_params[256];
 	unsigned		startup_params_len;
diff --git a/src/janitor.c b/src/janitor.c
index bda506d..a2b5286 100644
--- a/src/janitor.c
+++ b/src/janitor.c
@@ -236,6 +236,7 @@ void per_loop_maint(void)
 	List *item;
 	PgPool *pool;
 	int active = 0;
+	int partial_pause = 0;
 
 	/* dont touch anything if takeover is in progress */
 	if (cf_reboot)
@@ -247,7 +248,11 @@ void per_loop_maint(void)
 			continue;
 		switch (cf_pause_mode) {
 		case P_NONE:
-			per_loop_activate(pool);
+			if (pool->db->db_paused) {
+				partial_pause = 1;
+				active += per_loop_pause(pool);
+			} else
+				per_loop_activate(pool);
 			break;
 		case P_PAUSE:
 			active += per_loop_pause(pool);
@@ -264,7 +269,10 @@ void per_loop_maint(void)
 	case P_PAUSE:
 		if (!active)
 			admin_pause_done();
-	default:
+		break;
+	case P_NONE:
+		if (partial_pause && !active)
+			admin_pause_done();
 		break;
 	}
 }