From: Marko Kreen <markokr@gmail.com>
Date: Mon, 8 Oct 2007 07:06:41 +0000 (+0000)
Subject: switch to toggle between LIFO and round-robin
X-Git-Tag: pgbouncer_1_1~9
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5bcb2aa4b3848c6899ffa448f0e33ff34be15bf3;p=pgbouncer

switch to toggle between LIFO and round-robin
---

diff --git a/doc/pgbouncer.config.txt b/doc/pgbouncer.config.txt
index fa8d6a7..ee37abe 100644
--- a/doc/pgbouncer.config.txt
+++ b/doc/pgbouncer.config.txt
@@ -128,6 +128,16 @@ per-database config.
 
 Default: 20
 
+==== server_round_robin ====
+
+By default, pgbouncer reuses server connections in LIFO manner, so that few
+connections get the most load.  This gives best performance if you have single
+server serving a database.  But if there is TCP round-robin behind a database
+IP then it's better if pgbouncer also uses connections in that manner, thus
+achieving uniform load.
+
+Default: 0
+
 === Log settings ===
 
 ==== log_connections ====
diff --git a/etc/pgbouncer.ini b/etc/pgbouncer.ini
index a796f62..69bb173 100644
--- a/etc/pgbouncer.ini
+++ b/etc/pgbouncer.ini
@@ -93,6 +93,10 @@ log_disconnections = 1
 ; log error messages pooler sends to clients
 log_pooler_errors = 1
 
+
+; If off, then server connections are reused in LIFO manner
+;server_round_robin = 0
+
 ;;;
 ;;; Timeouts
 ;;;
diff --git a/src/bouncer.h b/src/bouncer.h
index a1ebd51..2b487bb 100644
--- a/src/bouncer.h
+++ b/src/bouncer.h
@@ -277,6 +277,7 @@ extern usec_t cf_server_login_retry;
 extern usec_t cf_query_timeout;
 extern usec_t cf_client_idle_timeout;
 extern usec_t cf_client_login_timeout;
+extern int cf_server_round_robin;
 
 extern int cf_auth_type;
 extern char *cf_auth_file;
diff --git a/src/main.c b/src/main.c
index cd00d1b..42b7511 100644
--- a/src/main.c
+++ b/src/main.c
@@ -81,6 +81,7 @@ int cf_default_pool_size = 20;
 char *cf_server_reset_query = "";
 char *cf_server_check_query = "select 1";
 usec_t cf_server_check_delay = 30 * USEC;
+int cf_server_round_robin = 0;
 
 usec_t cf_server_lifetime = 60*60*USEC;
 usec_t cf_server_idle_timeout = 10*60*USEC;
@@ -129,6 +130,7 @@ ConfElem bouncer_params[] = {
 {"server_idle_timeout",	true, CF_TIME, &cf_server_idle_timeout},
 {"server_connect_timeout",true, CF_TIME, &cf_server_connect_timeout},
 {"server_login_retry",	true, CF_TIME, &cf_server_login_retry},
+{"server_round_robin",	true, CF_INT, &cf_server_round_robin},
 
 {"pkt_buf",		false, CF_INT, &cf_sbuf_len},
 {"tcp_defer_accept",	false, CF_INT, &cf_tcp_defer_accept},
diff --git a/src/objects.c b/src/objects.c
index f6843b1..0a88787 100644
--- a/src/objects.c
+++ b/src/objects.c
@@ -257,7 +257,7 @@ void change_server_state(PgSocket *server, SocketState newstate)
 		statlist_append(&server->head, &pool->tested_server_list);
 		break;
 	case SV_IDLE:
-		if (server->close_needed)
+		if (server->close_needed || cf_server_round_robin)
 			/* try to avoid immediate usage then */
 			statlist_append(&server->head, &pool->idle_server_list);
 		else