add rule failover support. Failover mode can now be specified on a specific rule. This rule will only direct traffic to a single active interface, on failure of the ping target traffice will be directed out an alternate interface.

note: the one todo item for this feature is to add "stickiness" of an active interface. wlb re-evaluates all rules on an interface state change and this may cause the interface to change for failover mode. supporting this mode requires a less than trivial rewrite of the wlb decision code.:

4 files changed, 35 insertions, 7 deletions

diff --git a/src/lbdata.hh b/src/lbdata.hh
index 8077841..f4ddade 100644
--- a/src/lbdata.hh
+++ b/src/lbdata.hh
@@ -24,7 +24,8 @@ class LBRule {
 
   LBRule() :
     _proto("all"),
-    _exclude(false)
+    _exclude(false),
+    _failover(false)
       {}
 
  public:
@@ -38,6 +39,7 @@ class LBRule {
   string _d_port_ipt;
 
   bool _exclude;
+  bool _failover;
 
   string _in_iface;
   InterfaceDistColl _iface_dist_coll;
diff --git a/src/lbdatafactory.cc b/src/lbdatafactory.cc
index 086beed..16203b8 100644
--- a/src/lbdatafactory.cc
+++ b/src/lbdatafactory.cc
@@ -148,6 +148,9 @@ LBDataFactory::process(const vector<string> &path, int depth, const string &key,
     else if (depth > 0 && path[1] == "exclude") {
       process_rule_exclude(l_key,l_value);
     }
+    else if (depth > 0 && path[1] == "failover") {
+      process_rule_failover(l_key,l_value);
+    }
     else {
       process_rule(l_key,l_value);
     }
@@ -285,6 +288,12 @@ LBDataFactory::process_rule_exclude(const string &key, const string &value)
 }
 
 void
+LBDataFactory::process_rule_failover(const string &key, const string &value)
+{
+  _rule_iter->second._failover = true;
+}
+
+void
 LBDataFactory::process_rule_source(const string &key, const string &value)
 {
   if (key == "address") {
diff --git a/src/lbdatafactory.hh b/src/lbdatafactory.hh
index 1f6e0a0..6f5a11a 100644
--- a/src/lbdatafactory.hh
+++ b/src/lbdatafactory.hh
@@ -56,6 +56,9 @@ private:
   process_rule_exclude(const string &key, const string &value);
 
   void
+  process_rule_failover(const string &key, const string &value);
+
+  void
   process_rule_protocol(const string &key, const string &value);
 
   void
diff --git a/src/lbdecision.cc b/src/lbdecision.cc
index 751659d..e6cafac 100644
--- a/src/lbdecision.cc
+++ b/src/lbdecision.cc
@@ -307,7 +307,7 @@ LBDecision::execute(std::string cmd, std::string &stdout, bool read)
       char *buf = NULL;
       size_t len = 0;
       size_t read_len = 0;
-      while ((read_len = getline(&buf, &len, f)) != -1) {
+      while ((read_len = getline(&buf, &len, f)) != (size_t)-1) {
 	stdout += string(buf) + " ";
       }
 
@@ -334,12 +334,26 @@ LBDecision::get_new_weights(LBData &data, LBRule &rule)
     if (_debug) {
       cout << "LBDecision::get_new_weights(): " << iter->first << " is active: " << (data.is_active(iter->first) ? "true" : "false") << endl;
     }
-    if (data.is_active(iter->first)) {
-      weights.insert(pair<int,float>(ct,iter->second));
-      group += iter->second;
+
+    if (rule._failover == true) { //add single entry if active
+      if (weights.empty() == false) {
+	weights.insert(pair<int,float>(ct,0.));
+      }
+      else {
+	if (data.is_active(iter->first)) {
+	  weights.insert(pair<int,float>(ct,1.));
+	  group = 1;
+	}
+      }
     }
     else {
-      weights.insert(pair<int,float>(ct,0.));
+      if (data.is_active(iter->first)) {
+	weights.insert(pair<int,float>(ct,iter->second));
+	group += iter->second;
+      }
+      else {
+	weights.insert(pair<int,float>(ct,0.));
+      }
     }
     ++ct;
     ++iter;
@@ -356,7 +370,7 @@ LBDecision::get_new_weights(LBData &data, LBRule &rule)
       if (w_iter->second > 0.) { //can only be an integer value here
 	w = float(w_iter->second) / float(group);
       }
-      group -= w_iter->second;   //I THINK THIS NEEDS TO BE ADJUSTED TO THE OVERALL REMAINING VALUES. which is this...
+      group -= (int)w_iter->second;   //I THINK THIS NEEDS TO BE ADJUSTED TO THE OVERALL REMAINING VALUES. which is this...
       if (w < .01) {
 	weights.erase(w_iter++);
 	continue;