pgpool2.git / summary / log / commit / refs

commit    7986ffa5ed14f3b1bf668baa44bc76d9e28ac5bb
Author:   Tatsuo Ishii <ishii at sraoss.co.jp>
Date:     Sun Dec 06 07:46:57 2009 +0000

    Optimization when num_init_children == 1. In this case we don't need
    to wait for master returning a response before sending a query to the
    other nodes.


 pool_proto_modules.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/pool_proto_modules.c b/pool_proto_modules.c
index 332865723..52955e4da 100644
--- a/pool_proto_modules.c
+++ b/pool_proto_modules.c
@@ -557,6 +557,56 @@ POOL_STATUS NotificationResponse(POOL_CONNECTION *frontend,
 
 			}
 
+			/*
+			 * Optimization effort: If there's only one session, we do
+			 * not need to wait for the master node's response, and
+			 * could execute a query concurrently.
+			 */
+			if (pool_config->num_init_children == 1)
+			{
+				/* Send query to DB nodes */
+				for (i=0;i<NUM_BACKENDS;i++)
+				{
+					if (!VALID_BACKEND(i))
+						continue;
+
+					per_node_statement_log(backend, i, string);
+
+					if (send_simplequery_message(CONNECTION(backend, i), len, string, MAJOR(backend)) != POOL_CONTINUE)
+					{
+						free_parser();
+						return POOL_END;
+					}
+				}
+
+				/* Wait for response from DB nodes */
+				for (i=0;i<NUM_BACKENDS;i++)
+				{
+					if (!VALID_BACKEND(i))
+						continue;
+
+					if (wait_for_query_response(frontend, CONNECTION(backend, i), string, MAJOR(backend)) != POOL_CONTINUE)
+					{
+						/* Cancel current transaction */
+						CancelPacket cancel_packet;
+
+						cancel_packet.protoVersion = htonl(PROTO_CANCEL);
+						cancel_packet.pid = MASTER_CONNECTION(backend)->pid;
+						cancel_packet.key= MASTER_CONNECTION(backend)->key;
+						cancel_request(&cancel_packet);
+
+						free_parser();
+						return POOL_END;
+					}
+				}
+				if (commit)
+				{
+					TSTATE(backend) = 'I';
+				}
+				free_parser();
+				return POOL_CONTINUE;
+			}
+
 			/* Send the query to master node */
 
 			per_node_statement_log(backend, MASTER_NODE_ID, string);


[parent: d0b17681de64]