pgpool2.git / summary / log / commit / refs

commit    edc871810dca34dc8af56f23a9abc150580b8eb2
Author:   Yoshiyuki Asaba <y-asaba at pgfoundry.org>
Date:     Fri Jul 06 08:32:57 2007 +0000

    Load balancing node was chosen before sending "SELECT" statement.
    But this way had the following problems.
    
      psql>\d accounts
      Did not find any relation with OID XXX
    
    pgpool chooses it after receiving AuthenticationOK('R') message. So
    pgpool load balance to the same node inside a same session.


 child.c              | 42 ++++++++++++++++++++++++++++++++++++++++++
 pool_process_query.c | 30 ++----------------------------
 pool_type.h          |  1 +
 3 files changed, 45 insertions(+), 28 deletions(-)

diff --git a/child.c b/child.c
index 38d4b2bb7..86a47e174 100644
--- a/child.c
+++ b/child.c
@@ -67,6 +67,7 @@ static RETSIGTYPE wakeup_handler(int sig);
 static int send_params(POOL_CONNECTION *frontend, POOL_CONNECTION_POOL *backend);
 static void send_frontend_exits(void);
 static int s_do_auth(POOL_CONNECTION_POOL_SLOT *cp, char *password);
+static int select_load_balancing_node(void);
 
 /*
  * non 0 means SIGTERM(smart shutdown) or SIGINT(fast shutdown) has arrived
@@ -412,6 +413,9 @@ void do_child(int unix_fd, int inet_fd)
 		if (MAJOR(backend) == PROTO_MAJOR_V2)
 			TSTATE(backend) = 'I';
 
+		/* select load balancing node */
+		backend->info->load_balancing_node = select_load_balancing_node();
+
 		/* query process loop */
 		for (;;)
 		{
@@ -1668,3 +1672,41 @@ void connection_count_down(void)
 static RETSIGTYPE wakeup_handler(int sig)
 {
 }
+
+
+/*
+ *
+ */
+static int select_load_balancing_node(void)
+{
+	double total_weight,r;
+	int i;
+
+	/* choose a backend in random manner with weight */
+	selected_slot = 0;
+	total_weight = 0.0;
+
+	for (i=0;i<NUM_BACKENDS;i++)
+	{
+		if (VALID_BACKEND(i))
+		{
+			total_weight += BACKEND_INFO(i).backend_weight;
+		}
+	}
+	r = (((double)random())/RAND_MAX) * total_weight;
+	total_weight = 0.0;
+	for (i=0;i<NUM_BACKENDS;i++)
+	{
+		if (VALID_BACKEND(i))
+		{
+			if(r >= total_weight)
+				selected_slot = i;
+			else
+				break;
+			total_weight += BACKEND_INFO(i).backend_weight;
+		}
+	}
+
+	pool_debug("select_load_balancing_node: selected backend id is %d", selected_slot);
+	return selected_slot;
+}
diff --git a/pool_process_query.c b/pool_process_query.c
index f1bcd9360..91bc56eb4 100644
--- a/pool_process_query.c
+++ b/pool_process_query.c
@@ -3758,10 +3758,10 @@ static int is_commit_query(Node *node)
  */
 static void start_load_balance(POOL_CONNECTION_POOL *backend)
 {
+#ifdef NOT_USED
 	double total_weight,r;
 	int i;
 
-#ifdef NOT_USED
 	/* save backend connection slots */
 	for (i=0;i<NUM_BACKENDS;i++)
 	{
@@ -3772,31 +3772,6 @@ static void start_load_balance(POOL_CONNECTION_POOL *backend)
 	}
 #endif
 
-	/* choose a backend in random manner with weight */
-	selected_slot = 0;
-	total_weight = 0.0;
-
-	for (i=0;i<NUM_BACKENDS;i++)
-	{
-		if (VALID_BACKEND(i))
-		{
-			total_weight += BACKEND_INFO(i).backend_weight;
-		}
-	}
-	r = (((double)random())/RAND_MAX) * total_weight;
-	total_weight = 0.0;
-	for (i=0;i<NUM_BACKENDS;i++)
-	{
-		if (VALID_BACKEND(i))
-		{
-			if(r >= total_weight)
-				selected_slot = i;
-			else
-				break;
-			total_weight += BACKEND_INFO(i).backend_weight;
-		}
-	}
-
 	/* temporarily turn off replication mode */
 	if (REPLICATION)
 		replication_was_enabled = 1;
@@ -3809,8 +3784,7 @@ static void start_load_balance(POOL_CONNECTION_POOL *backend)
 #ifdef NOTUSED
 	backend->slots[0] = slots[selected_slot];
 #endif
-	LOAD_BALANCE_STATUS(selected_slot) = LOAD_SELECTED;
-	pool_debug("start_load_balance: selected backend id is %d", selected_slot);
+	LOAD_BALANCE_STATUS(backend->info->load_balancing_node) = LOAD_SELECTED;
 
 	/* start load balancing */
 	in_load_balance = 1;
diff --git a/pool_type.h b/pool_type.h
index c559c0da0..52a6d2d1a 100644
--- a/pool_type.h
+++ b/pool_type.h
@@ -109,6 +109,7 @@ typedef struct {
 	int			minor;	/* protocol minor version */
 	int			counter; /* used counter */
 	time_t 		create_time; /* connection creation time */
+	int load_balancing_node; /* load balancing node */
 } ConnectionInfo;
 
 


[parent: 790b231318ea]