--- a/src/director/director-connection.c	Mon May 18 13:56:07 2015 +0300
+++ b/src/director/director-connection.c	Mon May 18 07:49:15 2015 -0400
@@ -846,7 +846,8 @@
 	struct ip_addr ip;
 	const char *tag = "";
 	unsigned int vhost_count;
-	bool update;
+	bool update, down = FALSE;
+	time_t last_updown_change = 0;
 
 	if (str_array_length(args) < 2 ||
 	    net_addr2ip(args[0], &ip) < 0 ||
@@ -854,8 +855,17 @@
 		director_cmd_error(conn, "Invalid parameters");
 		return FALSE;
 	}
-	if (args[2] != NULL)
+	if (args[2] != NULL) {
 		tag = args[2];
+		if (args[3] != NULL) {
+			if ((args[3][0] != 'D' && args[3][0] != 'U') ||
+			    str_to_time(args[3]+1, &last_updown_change) < 0) {
+				director_cmd_error(conn, "Invalid updown parameters");
+				return FALSE;
+			}
+			down = args[3][0] == 'D';
+		}
+	}
 	if (conn->ignore_host_events) {
 		/* remote is sending hosts in a handshake, but it doesn't have
 		   a completed ring and we do. */
@@ -868,7 +878,10 @@
 		host = mail_host_add_ip(conn->dir->mail_hosts, &ip, tag);
 		update = TRUE;
 	} else {
-		update = host->vhost_count != vhost_count;
+		update = host->vhost_count != vhost_count ||
+			host->down != down ||
+			host->last_updown_change != last_updown_change;
+;
 		if (strcmp(tag, host->tag) != 0) {
 			i_error("director(%s): Host %s changed tag from '%s' to '%s'",
 				conn->name, net_ip2addr(&host->ip),
@@ -879,6 +892,8 @@
 	}
 
 	if (update) {
+		mail_host_set_down(conn->dir->mail_hosts, host,
+				   down, last_updown_change);
 		mail_host_set_vhost_count(conn->dir->mail_hosts,
 					  host, vhost_count);
 		director_update_host(conn->dir, conn->host, dir_host, host);
@@ -1581,14 +1596,23 @@
 director_connection_send_hosts(struct director_connection *conn, string_t *str)
 {
 	struct mail_host *const *hostp;
+	bool send_updowns;
+
+	send_updowns = conn->minor_version >= DIRECTOR_VERSION_UPDOWN;
 
 	str_printfa(str, "HOST-HAND-START\t%u\n", conn->dir->ring_handshaked);
 	array_foreach(mail_hosts_get(conn->dir->mail_hosts), hostp) {
+		struct mail_host *host = *hostp;
+
 		str_printfa(str, "HOST\t%s\t%u",
-			    net_ip2addr(&(*hostp)->ip), (*hostp)->vhost_count);
-		if ((*hostp)->tag[0] != '\0') {
+			    net_ip2addr(&host->ip), host->vhost_count);
+		if (host->tag[0] != '\0' || send_updowns) {
 			str_append_c(str, '\t');
-			str_append_tabescaped(str, (*hostp)->tag);
+			str_append_tabescaped(str, host->tag);
+		}
+		if (send_updowns) {
+			str_printfa(str, "\t%c%ld", host->down ? 'D' : 'U',
+				    (long)host->last_updown_change);
 		}
 		str_append_c(str, '\n');
 	}

--- a/src/director/director.c	Mon May 18 13:56:07 2015 +0300
+++ b/src/director/director.c	Mon May 18 07:49:15 2015 -0400
@@ -533,17 +533,19 @@
 		    net_ip2addr(&orig_src->ip), orig_src->port,
 		    orig_src->last_seq,
 		    net_ip2addr(&host->ip), host->vhost_count);
-	if (host->tag[0] == '\0')
-		;
-	else if (dir->ring_handshaked &&
-		 dir->ring_min_version < DIRECTOR_VERSION_TAGS) {
+	if (dir->ring_min_version >= DIRECTOR_VERSION_TAGS) {
+		str_append_c(str, '\t');
+		str_append_tabescaped(str, host->tag);
+	} else if (host->tag[0] != '\0' &&
+		   dir->ring_min_version < DIRECTOR_VERSION_TAGS) {
 		i_error("Ring has directors that don't support tags - removing host %s with tag '%s'",
 			net_ip2addr(&host->ip), host->tag);
 		director_remove_host(dir, NULL, NULL, host);
 		return;
-	} else {
-		str_append_c(str, '\t');
-		str_append_tabescaped(str, host->tag);
+	}
+	if (dir->ring_min_version >= DIRECTOR_VERSION_UPDOWN) {
+		str_printfa(str, "\t%c%ld", host->down ? 'D' : 'U',
+			    (long)host->last_updown_change);
 	}
 	str_append_c(str, '\n');
 	director_update_send(dir, src, str_c(str));

--- a/src/director/director.h	Mon May 18 13:56:07 2015 +0300
+++ b/src/director/director.h	Mon May 18 07:49:15 2015 -0400
@@ -6,7 +6,7 @@
 
 #define DIRECTOR_VERSION_NAME "director"
 #define DIRECTOR_VERSION_MAJOR 1
-#define DIRECTOR_VERSION_MINOR 5
+#define DIRECTOR_VERSION_MINOR 6
 
 /* weak users supported in protocol */
 #define DIRECTOR_VERSION_WEAK_USERS 1
@@ -20,6 +20,8 @@
 #define DIRECTOR_VERSION_OPTIONS 5
 /* user tags supported */
 #define DIRECTOR_VERSION_TAGS 5
+/* up/down state is tracked */
+#define DIRECTOR_VERSION_UPDOWN 6
 
 /* Minimum time between even attempting to communicate with a director that
    failed due to a protocol error. */

--- a/src/director/doveadm-connection.c	Mon May 18 13:56:07 2015 +0300
+++ b/src/director/doveadm-connection.c	Mon May 18 07:49:15 2015 -0400
@@ -51,6 +51,8 @@
 			    net_ip2addr(&(*hostp)->ip), (*hostp)->vhost_count,
 			    (*hostp)->user_count);
 		str_append_tabescaped(str, (*hostp)->tag);
+		str_printfa(str, "\t%c\t%ld", (*hostp)->down ? 'D' : 'U',
+			    (long)(*hostp)->last_updown_change);
 		str_append_c(str, '\n');
 	}
 	str_append_c(str, '\n');
@@ -285,6 +287,33 @@
 }
 
 static bool
+doveadm_cmd_host_updown(struct doveadm_connection *conn, bool down,
+			const char *line)
+{
+	struct mail_host *host;
+	struct ip_addr ip;
+
+	if (net_addr2ip(line, &ip) < 0) {
+		i_error("doveadm sent invalid %s parameters: %s",
+			down ? "HOST-DOWN" : "HOST-UP", line);
+		return FALSE;
+	}
+	host = mail_host_lookup(conn->dir->mail_hosts, &ip);
+	if (host == NULL) {
+		o_stream_nsend_str(conn->output, "NOTFOUND\n");
+		return TRUE;
+	}
+	if (host->down != down) {
+		mail_host_set_down(conn->dir->mail_hosts, host,
+				   down, ioloop_time);
+		director_update_host(conn->dir, conn->dir->self_host,
+				     NULL, host);
+	}
+	o_stream_nsend(conn->output, "OK\n", 3);
+	return TRUE;
+}
+
+static bool
 doveadm_cmd_host_remove(struct doveadm_connection *conn, const char *line)
 {
 	struct mail_host *host;
@@ -587,6 +616,10 @@
 			ret = doveadm_cmd_director_remove(conn, args);
 		else if (strcmp(cmd, "HOST-SET") == 0)
 			ret = doveadm_cmd_host_set(conn, args);
+		else if (strcmp(cmd, "HOST-UP") == 0)
+			ret = doveadm_cmd_host_updown(conn, FALSE, args);
+		else if (strcmp(cmd, "HOST-DOWN") == 0)
+			ret = doveadm_cmd_host_updown(conn, TRUE, args);
 		else if (strcmp(cmd, "HOST-REMOVE") == 0)
 			ret = doveadm_cmd_host_remove(conn, args);
 		else if (strcmp(cmd, "HOST-FLUSH") == 0)

--- a/src/director/mail-host.c	Mon May 18 13:56:07 2015 +0300
+++ b/src/director/mail-host.c	Mon May 18 07:49:15 2015 -0400
@@ -58,6 +58,9 @@
 	char num_str[MAX_INT_STRLEN];
 	unsigned int i, j;
 
+	if (host->down)
+		return;
+
 	ip_str = net_ip2addr(&host->ip);
 
 	md5_init(&md5_ctx);
@@ -99,6 +102,8 @@
 	/* rebuild vhosts */
 	array_clear(&list->vhosts);
 	array_foreach(&list->hosts, hostp) {
+		if ((*hostp)->down)
+			continue;
 		for (i = 0; i < (*hostp)->vhost_count; i++) {
 			vhost = array_append_space(&list->vhosts);
 			vhost->host = *hostp;
@@ -269,6 +274,16 @@
 	host->tag = i_strdup(tag);
 }
 
+void mail_host_set_down(struct mail_host_list *list,
+			struct mail_host *host, bool down, time_t timestamp)
+{
+	if (host->down != down) {
+		host->down = down;
+		host->last_updown_change = timestamp;
+		list->hosts_unsorted = TRUE;
+	}
+}
+
 void mail_host_set_vhost_count(struct mail_host_list *list,
 			       struct mail_host *host, unsigned int vhost_count)
 {

--- a/src/director/mail-host.h	Mon May 18 13:56:07 2015 +0300
+++ b/src/director/mail-host.h	Mon May 18 07:49:15 2015 -0400
@@ -8,6 +8,10 @@
 struct mail_host {
 	unsigned int user_count;
 	unsigned int vhost_count;
+	/* server up/down. down=TRUE has effectively the same result as if
+	   vhost_count=0. */
+	bool down;
+	time_t last_updown_change;
 
 	struct ip_addr ip;
 	char *tag;
@@ -26,6 +30,8 @@
 int mail_hosts_parse_and_add(struct mail_host_list *list,
 			     const char *hosts_string);
 void mail_host_set_tag(struct mail_host *host, const char *tag);
+void mail_host_set_down(struct mail_host_list *list,
+			struct mail_host *host, bool down, time_t timestamp);
 void mail_host_set_vhost_count(struct mail_host_list *list,
 			       struct mail_host *host,
 			       unsigned int vhost_count);

--- a/src/doveadm/doveadm-director.c	Mon May 18 13:56:07 2015 +0300
+++ b/src/doveadm/doveadm-director.c	Mon May 18 07:49:15 2015 -0400
@@ -176,21 +176,32 @@
 	doveadm_print_init(DOVEADM_PRINT_TYPE_TABLE);
 	doveadm_print_header_simple("mail server ip");
 	doveadm_print_header_simple("tag");
-	doveadm_print_header("vhosts", "vhosts",
-			     DOVEADM_PRINT_HEADER_FLAG_RIGHT_JUSTIFY);
-	doveadm_print_header("users", "users",
-			     DOVEADM_PRINT_HEADER_FLAG_RIGHT_JUSTIFY);
+	doveadm_print_header_simple("vhosts");
+	doveadm_print_header_simple("state");
+	doveadm_print_header("state-changed", "state changed", 0);
+	doveadm_print_header_simple("users");
 
 	director_send(ctx, "HOST-LIST\n");
 	while ((line = i_stream_read_next_line(ctx->input)) != NULL) {
 		if (*line == '\0')
 			break;
 		T_BEGIN {
+			unsigned int arg_count;
+			time_t ts;
+
 			args = t_strsplit_tab(line);
-			if (str_array_length(args) >= 4) {
-				doveadm_print(args[0]);
+			arg_count = str_array_length(args);
+			if (arg_count >= 6) {
+				/* ip vhosts users tag updown updown-ts */
+				doveadm_print(args[0]); 
 				doveadm_print(args[3]);
 				doveadm_print(args[1]);
+				doveadm_print(args[4][0] == 'D' ? "down" : "up");
+				if (str_to_time(args[5], &ts) < 0 ||
+				    ts <= 0)
+					doveadm_print("-");
+				else
+					doveadm_print(unixdate2str(ts));
 				doveadm_print(args[2]);
 			}
 		} T_END;
@@ -447,22 +458,24 @@
 	director_disconnect(ctx);
 }
 
-static void cmd_director_remove(int argc, char *argv[])
+static void
+cmd_director_ipcmd(const char *cmd_name, doveadm_command_t *cmd,
+		   const char *success_result, int argc, char *argv[])
 {
 	struct director_context *ctx;
 	struct ip_addr *ips;
 	unsigned int i, ips_count;
 	const char *host, *line;
 
-	ctx = cmd_director_init(argc, argv, "a:", cmd_director_remove);
+	ctx = cmd_director_init(argc, argv, "a:", cmd);
 	host = argv[optind++];
 	if (host == NULL || argv[optind] != NULL)
-		director_cmd_help(cmd_director_remove);
+		director_cmd_help(cmd);
 
 	director_get_host(host, &ips, &ips_count);
 	for (i = 0; i < ips_count; i++) {
 		director_send(ctx, t_strdup_printf(
-			"HOST-REMOVE\t%s\n", net_ip2addr(&ips[i])));
+			"%s\t%s\n", cmd_name, net_ip2addr(&ips[i])));
 	}
 	for (i = 0; i < ips_count; i++) {
 		line = i_stream_read_next_line(ctx->input);
@@ -476,12 +489,30 @@
 				line == NULL ? "failed" : line);
 			doveadm_exit_code = EX_TEMPFAIL;
 		} else if (doveadm_verbose) {
-			printf("%s: removed\n", net_ip2addr(&ips[i]));
+			printf("%s: %s\n", net_ip2addr(&ips[i]), success_result);
 		}
 	}
 	director_disconnect(ctx);
 }
 
+static void cmd_director_remove(int argc, char *argv[])
+{
+	cmd_director_ipcmd("HOST-REMOVE", cmd_director_remove,
+			   "removed", argc, argv);
+}
+
+static void cmd_director_up(int argc, char *argv[])
+{
+	cmd_director_ipcmd("HOST-UP", cmd_director_up,
+			   "up", argc, argv);
+}
+
+static void cmd_director_down(int argc, char *argv[])
+{
+	cmd_director_ipcmd("HOST-DOWN", cmd_director_down,
+			   "down", argc, argv);
+}
+
 static void cmd_director_move(int argc, char *argv[])
 {
 	struct director_context *ctx;
@@ -777,6 +808,10 @@
 	  "[-a <director socket path>] [-f <users file>] [-h | -u] [<host>]" },
 	{ cmd_director_add, "director add",
 	  "[-a <director socket path>] [-t <tag>] <host> [<vhost count>]" },
+	{ cmd_director_up, "director up",
+	  "[-a <director socket path>] <host>" },
+	{ cmd_director_down, "director down",
+	  "[-a <director socket path>] <host>" },
 	{ cmd_director_remove, "director remove",
 	  "[-a <director socket path>] <host>" },
 	{ cmd_director_move, "director move",