BUG/MEDIUM: correctly disable servers tracking another disabled servers.

In a config where server "s1" is marked disabled and "s2" tracks "s1",
s2 appears disabled on the stats but is still inserted into the LB farm
because the tracking is resolved too late in the configuration process.

We now resolve tracked servers before building LB maps and we also mark
the tracking server in maintenance mode, which previously was not done,
causing half of the issue.

Last point is that we also protect srv_is_usable() against electing a
server marked for maintenance. This is not absolutely needed but is a
safe choice and makes a lot of sense.

This fix must be backported to 1.4.

diff --git a/include/proto/backend.h b/include/proto/backend.h
index a6f1c9f4d78c6d6e7e8164b99c5f61eef1066416..c8322b8eba6dba444b8bec55cc230335268ad881 100644 (file)
--- a/include/proto/backend.h
+++ b/include/proto/backend.h
@@ -1,23 +1,23 @@
 /*
-  include/proto/backend.h
-  Functions prototypes for the backend.
-
-  Copyright (C) 2000-2009 Willy Tarreau - w@1wt.eu
-  
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation, version 2.1
-  exclusively.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-*/
+ * include/proto/backend.h
+ * Functions prototypes for the backend.
+ *
+ * Copyright (C) 2000-2012 Willy Tarreau - w@1wt.eu
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
 
 #ifndef _PROTO_BACKEND_H
 #define _PROTO_BACKEND_H
@@ -51,7 +51,7 @@ static inline int srv_is_usable(int state, int weight)
 {
        if (!weight)
                return 0;
-       if (state & SRV_GOINGDOWN)
+       if (state & (SRV_GOINGDOWN | SRV_MAINTAIN))
                return 0;
        if (!(state & SRV_RUNNING))
                return 0;

diff --git a/src/cfgparse.c b/src/cfgparse.c
index b881cd94d6a80960e6862bc91747785ac538687d..4fed92e80b13b01ea03283599e1bb1c3e64beea4 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -6076,6 +6076,97 @@ out_uri_auth_compat:
                curproxy->lbprm.wmult = 1; /* default weight multiplier */
                curproxy->lbprm.wdiv  = 1; /* default weight divider */
 
+               /*
+                * If this server supports a maxconn parameter, it needs a dedicated
+                * tasks to fill the emptied slots when a connection leaves.
+                * Also, resolve deferred tracking dependency if needed.
+                */
+               newsrv = curproxy->srv;
+               while (newsrv != NULL) {
+                       if (newsrv->minconn > newsrv->maxconn) {
+                               /* Only 'minconn' was specified, or it was higher than or equal
+                                * to 'maxconn'. Let's turn this into maxconn and clean it, as
+                                * this will avoid further useless expensive computations.
+                                */
+                               newsrv->maxconn = newsrv->minconn;
+                       } else if (newsrv->maxconn && !newsrv->minconn) {
+                               /* minconn was not specified, so we set it to maxconn */
+                               newsrv->minconn = newsrv->maxconn;
+                       }
+
+                       if (newsrv->trackit) {
+                               struct proxy *px;
+                               struct server *srv;
+                               char *pname, *sname;
+
+                               pname = newsrv->trackit;
+                               sname = strrchr(pname, '/');
+
+                               if (sname)
+                                       *sname++ = '\0';
+                               else {
+                                       sname = pname;
+                                       pname = NULL;
+                               }
+
+                               if (pname) {
+                                       px = findproxy(pname, PR_CAP_BE);
+                                       if (!px) {
+                                               Alert("config : %s '%s', server '%s': unable to find required proxy '%s' for tracking.\n",
+                                                       proxy_type_str(curproxy), curproxy->id,
+                                                       newsrv->id, pname);
+                                               cfgerr++;
+                                               goto next_srv;
+                                       }
+                               } else
+                                       px = curproxy;
+
+                               srv = findserver(px, sname);
+                               if (!srv) {
+                                       Alert("config : %s '%s', server '%s': unable to find required server '%s' for tracking.\n",
+                                               proxy_type_str(curproxy), curproxy->id,
+                                               newsrv->id, sname);
+                                       cfgerr++;
+                                       goto next_srv;
+                               }
+
+                               if (!(srv->state & SRV_CHECKED)) {
+                                       Alert("config : %s '%s', server '%s': unable to use %s/%s for "
+                                               "tracking as it does not have checks enabled.\n",
+                                               proxy_type_str(curproxy), curproxy->id,
+                                               newsrv->id, px->id, srv->id);
+                                       cfgerr++;
+                                       goto next_srv;
+                               }
+
+                               if (curproxy != px &&
+                                       (curproxy->options & PR_O_DISABLE404) != (px->options & PR_O_DISABLE404)) {
+                                       Alert("config : %s '%s', server '%s': unable to use %s/%s for"
+                                               "tracking: disable-on-404 option inconsistency.\n",
+                                               proxy_type_str(curproxy), curproxy->id,
+                                               newsrv->id, px->id, srv->id);
+                                       cfgerr++;
+                                       goto next_srv;
+                               }
+
+                               /* if the other server is forced disabled, we have to do the same here */
+                               if (srv->state & SRV_MAINTAIN) {
+                                       newsrv->state |= SRV_MAINTAIN;
+                                       newsrv->state &= ~SRV_RUNNING;
+                                       newsrv->health = 0;
+                               }
+
+                               newsrv->track = srv;
+                               newsrv->tracknext = srv->tracknext;
+                               srv->tracknext = newsrv;
+
+                               free(newsrv->trackit);
+                               newsrv->trackit = NULL;
+                       }
+               next_srv:
+                       newsrv = newsrv->next;
+               }
+
                /* We have to initialize the server lookup mechanism depending
                 * on what LB algorithm was choosen.
                 */
@@ -6208,89 +6299,6 @@ out_uri_auth_compat:
                        newsrv = newsrv->next;
                }
 
-               /*
-                * If this server supports a maxconn parameter, it needs a dedicated
-                * tasks to fill the emptied slots when a connection leaves.
-                * Also, resolve deferred tracking dependency if needed.
-                */
-               newsrv = curproxy->srv;
-               while (newsrv != NULL) {
-                       if (newsrv->minconn > newsrv->maxconn) {
-                               /* Only 'minconn' was specified, or it was higher than or equal
-                                * to 'maxconn'. Let's turn this into maxconn and clean it, as
-                                * this will avoid further useless expensive computations.
-                                */
-                               newsrv->maxconn = newsrv->minconn;
-                       } else if (newsrv->maxconn && !newsrv->minconn) {
-                               /* minconn was not specified, so we set it to maxconn */
-                               newsrv->minconn = newsrv->maxconn;
-                       }
-
-                       if (newsrv->trackit) {
-                               struct proxy *px;
-                               struct server *srv;
-                               char *pname, *sname;
-
-                               pname = newsrv->trackit;
-                               sname = strrchr(pname, '/');
-
-                               if (sname)
-                                       *sname++ = '\0';
-                               else {
-                                       sname = pname;
-                                       pname = NULL;
-                               }
-
-                               if (pname) {
-                                       px = findproxy(pname, PR_CAP_BE);
-                                       if (!px) {
-                                               Alert("config : %s '%s', server '%s': unable to find required proxy '%s' for tracking.\n",
-                                                       proxy_type_str(curproxy), curproxy->id,
-                                                       newsrv->id, pname);
-                                               cfgerr++;
-                                               goto next_srv;
-                                       }
-                               } else
-                                       px = curproxy;
-
-                               srv = findserver(px, sname);
-                               if (!srv) {
-                                       Alert("config : %s '%s', server '%s': unable to find required server '%s' for tracking.\n",
-                                               proxy_type_str(curproxy), curproxy->id,
-                                               newsrv->id, sname);
-                                       cfgerr++;
-                                       goto next_srv;
-                               }
-
-                               if (!(srv->state & SRV_CHECKED)) {
-                                       Alert("config : %s '%s', server '%s': unable to use %s/%s for "
-                                               "tracking as it does not have checks enabled.\n",
-                                               proxy_type_str(curproxy), curproxy->id,
-                                               newsrv->id, px->id, srv->id);
-                                       cfgerr++;
-                                       goto next_srv;
-                               }
-
-                               if (curproxy != px &&
-                                       (curproxy->options & PR_O_DISABLE404) != (px->options & PR_O_DISABLE404)) {
-                                       Alert("config : %s '%s', server '%s': unable to use %s/%s for"
-                                               "tracking: disable-on-404 option inconsistency.\n",
-                                               proxy_type_str(curproxy), curproxy->id,
-                                               newsrv->id, px->id, srv->id);
-                                       cfgerr++;
-                                       goto next_srv;
-                               }
-
-                               newsrv->track = srv;
-                               newsrv->tracknext = srv->tracknext;
-                               srv->tracknext = newsrv;
-
-                               free(newsrv->trackit);
-                       }
-               next_srv:
-                       newsrv = newsrv->next;
-               }
-
                if (curproxy->cap & PR_CAP_FE) {
                        curproxy->accept = frontend_accept;