Final guardfraction preparations for upstream merge.

- Write a changes file.
- Change some logs to lesser severities.

changes/bug9321

@@ -0,0 +1,7 @@
+  o Major features:
+    - Introduce the Guardfraction feature which improves the load
+      balancing of path selection towards guard nodes. Specifically,
+      it aims to reduce the traffic gap that guard nodes experience
+      when they first get the Guard flag. This is a required step if
+      we want to increase the guard lifetime to 9 months or greater.
+      Resolves ticket 9321.

src/or/dirserv.c

@@ -2436,7 +2436,7 @@ dirserv_read_guardfraction_file_from_str(const char *guardfraction_file_str,
 
   retval = 0;
 
-  log_warn(LD_CONFIG,
+  log_info(LD_CONFIG,
            "Successfully parsed guardfraction file with %d consensuses over "
            "%d days. Parsed %d nodes and applied %d of them%s.",
            total_consensuses, total_days, guards_read_n, guards_applied_n,

src/or/dirvote.c

@@ -1020,7 +1020,7 @@ update_total_bandwidth_weights(const routerstatus_t *rs,
   int guardfraction_bandwidth = 0;
 
   if (!rs->has_bandwidth) {
-    log_warn(LD_BUG, "Missing consensus bandwidth for router %s",
+    log_info(LD_BUG, "Missing consensus bandwidth for router %s",
              rs->nickname);
     return;
   }

src/or/routerlist.c

@@ -2166,7 +2166,7 @@ compute_weighted_bandwidths(const smartlist_t *sl,
         guardfraction_bw.guard_bw * weight +
         guardfraction_bw.non_guard_bw * weight_without_guard_flag;
 
-      log_warn(LD_GENERAL, "%s: Guardfraction weight %f instead of %f (%s)",
+      log_debug(LD_GENERAL, "%s: Guardfraction weight %f instead of %f (%s)",
                 node->rs->nickname, final_weight, weight*this_bw,
                 bandwidth_weight_rule_to_string(rule));
     } else { /* no guardfraction information. calculate the weight normally. */

src/or/routerparse.c

@@ -1831,7 +1831,7 @@ routerstatus_parse_guardfraction(const char *guardfraction_str,
     return -1;
   }
 
-  log_warn(LD_GENERAL, "[*] Parsed %s guardfraction '%s' for '%s'.",
+  log_debug(LD_GENERAL, "[*] Parsed %s guardfraction '%s' for '%s'.",
             is_consensus ? "consensus" : "vote",
             guardfraction_str, rs->nickname);