diff --git a/include/maxscale/response_stat.hh b/include/maxscale/response_stat.hh
index d4c437c60..90be34ed0 100644
--- a/include/maxscale/response_stat.hh
+++ b/include/maxscale/response_stat.hh
@@ -16,33 +16,42 @@
 #include <maxbase/stopwatch.hh>
 #include <maxbase/average.hh>
 
+/** This could arguably be a utility, but is written specifically for rwsplit
+ *  so it stays here at least for now.
+ */
 namespace maxscale
 {
 /**
- * Query response time average for a backend. Uses median of N samples to filter noise,
- * then uses those medians to calculate the average response time.
+ * Query response statistics. Uses median of N samples to filter noise, then
+ * uses those medians to calculate the average response time.
+ * The class makes an average of the durations between calls to query_started()
+ * and query_ended(). Once the stats are good, sync_time_reached(int max) returns true,
+ * based on the average containing at least max samples (or medians), or the time
+ * sync_duration (constructor arg) has passed since the last reset().
  */
 class ResponseStat
 {
 public:
     /*
-     * @param num_filter_samples - collect num samples, use median (digital filter)
-     * @param sync_duration      - this much time between synchronize to server stats.
+     * @param num_filter_samples - collect num samples, use median
+     * @param num_synch_medians  - this many medians before the average should be synced, or
+     * @param sync_duration      - this much time between syncs.
      */
-    ResponseStat(int num_filter_samples = 9,
-                 maxbase::Duration sync_duration = std::chrono::milliseconds(250));
+    ResponseStat(int num_filter_samples = 5,
+                 int num_synch_medians = 500,
+                 maxbase::Duration sync_duration = std::chrono::seconds(5));
 
     void              query_started();
-    void              query_ended();    // ok to call without a query_started
-    bool              make_valid();     // make valid even if there are only filter_samples
+    void              query_ended();// ok to call without a query_started
+    bool              make_valid(); // make valid even if there are too few filter_samples
     bool              is_valid() const;
     int               num_samples() const;
     maxbase::Duration average() const;
-    bool              sync_time_reached();  // is it time to apply the average to the server?
+    bool              sync_time_reached();  // is it time to apply the average?
     void              reset();
-
 private:
     const int                      m_num_filter_samples;
+    const int                      m_num_synch_medians;
     const maxbase::Duration        m_sync_duration;
     int                            m_sample_count;
     std::vector<maxbase::Duration> m_samples;   // N sampels from which median is used
diff --git a/server/core/response_stat.cc b/server/core/response_stat.cc
index f090cab66..a198da64d 100644
--- a/server/core/response_stat.cc
+++ b/server/core/response_stat.cc
@@ -17,8 +17,10 @@
 namespace maxscale
 {
 ResponseStat::ResponseStat(int num_filter_samples,
+                           int num_synch_medians,
                            maxbase::Duration sync_duration)
     : m_num_filter_samples {num_filter_samples}
+    , m_num_synch_medians{num_synch_medians}
     , m_sync_duration{sync_duration}
     , m_sample_count{0}
     , m_samples(num_filter_samples)
@@ -37,7 +39,7 @@ void ResponseStat::query_ended()
 {
     if (m_last_start == maxbase::TimePoint())
     {
-        // m_last_start is defaulted. Ignore, avoids extra logic at call sites.
+        // m_last_start is defaulted. Ignore, avoids extra logic in call sites.
         return;
     }
     m_samples[m_sample_count] = maxbase::Clock::now() - m_last_start;
@@ -56,11 +58,9 @@ bool ResponseStat::make_valid()
 {
     if (!m_average.num_samples() && m_sample_count)
     {
-        std::sort(m_samples.begin(), m_samples.begin() + m_sample_count);
         maxbase::Duration new_sample = m_samples[m_sample_count / 2];
         m_average.add(std::chrono::duration<double>(new_sample).count());
         m_sample_count = 0;
-        m_last_start = maxbase::TimePoint();
     }
 
     return is_valid();
@@ -84,7 +84,8 @@ maxbase::Duration ResponseStat::average() const
 bool ResponseStat::sync_time_reached()
 {
     auto now = maxbase::Clock::now();
-    bool reached = m_next_sync < now;
+    bool reached = m_next_sync < now
+        || m_average.num_samples() >= m_num_synch_medians;
 
     if (reached)
     {
diff --git a/server/modules/monitor/mariadbmon/cluster_manipulation.cc b/server/modules/monitor/mariadbmon/cluster_manipulation.cc
index 5fed0e285..1a36eb694 100644
--- a/server/modules/monitor/mariadbmon/cluster_manipulation.cc
+++ b/server/modules/monitor/mariadbmon/cluster_manipulation.cc
@@ -865,7 +865,7 @@ bool MariaDBMonitor::failover_perform(ClusterOperation& op)
             wait_cluster_stabilization_ex(op, redirected_slaves);
             MXS_DEBUG("Failover: slave replication confirmation took %.1f seconds with "
                       "%.1f seconds to spare.",
-                      timer.lap(), op.time_remaining.secs());
+                      timer.lap().secs(), op.time_remaining.secs());
         }
     }
     return rval;