dovecot-1.2: login proxy: Improvements to "fail immediately if s...

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-1.2/rev/34179f0f4d6a
changeset: 9313:34179f0f4d6a
user:      Timo Sirainen <tss at iki.fi>
date:      Wed Aug 12 17:55:14 2009 -0400
description:
login proxy: Improvements to "fail immediately if server is down" handling.
Now we use more precise timestamps. Also don't mark server as failed if
another connect had succeeded after we started connecting.

diffstat:

2 files changed, 22 insertions(+), 6 deletions(-)
src/login-common/login-proxy-state.h |    4 ++--
src/login-common/login-proxy.c       |   24 ++++++++++++++++++++----

diffs (93 lines):

diff -r 00a1d109ecf6 -r 34179f0f4d6a src/login-common/login-proxy-state.h
--- a/src/login-common/login-proxy-state.h	Wed Aug 12 17:27:25 2009 -0400
+++ b/src/login-common/login-proxy-state.h	Wed Aug 12 17:55:14 2009 -0400
@@ -2,8 +2,8 @@
 #define LOGIN_PROXY_STATE_H
 
 struct login_proxy_record {
-	time_t last_failure;
-	time_t last_success;
+	struct timeval last_failure;
+	struct timeval last_success;
 	unsigned int num_waiting_connections;
 };
 
diff -r 00a1d109ecf6 -r 34179f0f4d6a src/login-common/login-proxy.c
--- a/src/login-common/login-proxy.c	Wed Aug 12 17:27:25 2009 -0400
+++ b/src/login-common/login-proxy.c	Wed Aug 12 17:55:14 2009 -0400
@@ -6,6 +6,7 @@
 #include "ostream.h"
 #include "llist.h"
 #include "str-sanitize.h"
+#include "time-util.h"
 #include "client-common.h"
 #include "ssl-proxy.h"
 #include "login-proxy-state.h"
@@ -25,6 +26,7 @@ struct login_proxy {
 	struct ip_addr ip;
 	struct ssl_proxy *ssl_proxy;
 
+	struct timeval created;
 	struct timeout *to;
 	struct login_proxy_record *state_rec;
 
@@ -132,6 +134,19 @@ static void proxy_plain_connected(struct
 		io_add(proxy->server_fd, IO_READ, proxy_prelogin_input, proxy);
 }
 
+static void proxy_fail_connect(struct login_proxy *proxy)
+{
+	if (timeval_cmp(&proxy->created, &proxy->state_rec->last_success) < 0) {
+		/* there was a successful connection done since we started
+		   connecting. perhaps this is just a temporary one-off
+		   failure. */
+	} else {
+		proxy->state_rec->last_failure = ioloop_timeval;
+	}
+	proxy->state_rec->num_waiting_connections--;
+	proxy->state_rec = NULL;
+}
+
 static void proxy_wait_connect(struct login_proxy *proxy)
 {
 	int err;
@@ -140,11 +155,11 @@ static void proxy_wait_connect(struct lo
 	if (err != 0) {
 		i_error("proxy: connect(%s, %u) failed: %s",
 			proxy->host, proxy->port, strerror(err));
-		proxy->state_rec->last_failure = ioloop_time;
+		proxy_fail_connect(proxy);
                 login_proxy_free(&proxy);
 		return;
 	}
-	proxy->state_rec->last_success = ioloop_time;
+	proxy->state_rec->last_success = ioloop_timeval;
 	proxy->state_rec->num_waiting_connections--;
 	proxy->state_rec = NULL;
 
@@ -166,7 +181,7 @@ static void proxy_connect_timeout(struct
 static void proxy_connect_timeout(struct login_proxy *proxy)
 {
 	i_error("proxy: connect(%s, %u) timed out", proxy->host, proxy->port);
-	proxy->state_rec->last_failure = ioloop_time;
+	proxy_fail_connect(proxy);
 	login_proxy_free(&proxy);
 }
 
@@ -194,7 +209,7 @@ login_proxy_new(struct client *client, c
 	}
 
 	rec = login_proxy_state_get(proxy_state, &ip);
-	if (rec->last_failure > rec->last_success &&
+	if (timeval_cmp(&rec->last_failure, &rec->last_success) > 0 &&
 	    rec->num_waiting_connections != 0) {
 		/* the server is down. fail immediately */
 		return NULL;
@@ -208,6 +223,7 @@ login_proxy_new(struct client *client, c
 	}
 
 	proxy = i_new(struct login_proxy, 1);
+	proxy->created = ioloop_timeval;
 	proxy->host = i_strdup(host);
 	proxy->user = i_strdup(client->virtual_user);
 	proxy->port = port;