Fix Halo tests in v3.6.3 of GlusterFS + minor SHD bug fix

Summary:
- SHD is now excluded from the max-replicas policy.  We'd need
  to make an SHD specific tunable for this to make tests reliably
  pass, and frankly it probably makes things more intuitive having
  SHD excluded (i.e. SHD can always see everything).
- Updated the halo-failover-enabled test, I think it's a bit more clear
  now, and works reliably.  halo.t fixed after fixing the SHD
  max-replicas bug.

Test Plan: - Run prove tests -> https://phabricator.fb.com/P19872728

Reviewers: dph, sshreyas

Reviewed By: sshreyas

FB-commit-id: e425e6651cd02691d36427831b6b8ca206d0f78f

Change-Id: I57855ef99628146c32de59af475b096bd91d6012
Signed-off-by: Kevin Vigor <kvigor@fb.com>
Reviewed-on: http://review.gluster.org/16305
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Shreyas Siravara <sshreyas@fb.com>

1 files changed, 32 insertions, 7 deletions

diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c
index 8e46117b025..c4b6fd6a9b6 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -4253,6 +4253,21 @@ find_worst_up_child (xlator_t *this)
         return worst_child;
 }
 
+static void dump_halo_states (xlator_t *this) {
+        afr_private_t   *priv               = NULL;
+        int             i                   = -1;
+
+        priv = this->private;
+
+        for (i = 0; i < priv->child_count; i++) {
+                gf_log (this->name, GF_LOG_DEBUG,
+                        "Child %d halo state: %s (%"PRIi64"ms)",
+                        i,
+                        priv->child_up[i] ? CHILD_UP_STR : CHILD_DOWN_STR,
+                        priv->child_latency[i]);
+        }
+}
+
 static void
 _afr_handle_ping_event (xlator_t *this, xlator_t *child_xlator,
                 const int idx, const int64_t halo_max_latency_msec,
@@ -4264,7 +4279,6 @@ _afr_handle_ping_event (xlator_t *this, xlator_t *child_xlator,
         int             up_children         = 0;
         int             best_down_child     = 0;
         uint64_t        latency_samples     = 0;
-        char            *child_state_str    = NULL;
 
         priv = this->private;
 
@@ -4276,13 +4290,7 @@ _afr_handle_ping_event (xlator_t *this, xlator_t *child_xlator,
         for (i = 0; i < priv->child_count; i++) {
                 if (priv->child_up[i] == 1) {
                         up_children++;
-                        child_state_str = CHILD_UP_STR;
-                } else {
-                    child_state_str = CHILD_DOWN_STR;
                 }
-                gf_log (child_xlator->name, GF_LOG_DEBUG,
-                        "Child %d halo state: %s (%"PRIi64"ms)",
-                        i, child_state_str, priv->child_latency[i]);
         }
 
         /* Don't do anything until you have some minimum numbner of
@@ -4340,6 +4348,7 @@ _afr_handle_ping_event (xlator_t *this, xlator_t *child_xlator,
          * Case 3: Child latency is within halo,and currently marked up,
          * mark it down if it's the highest latency child and the
          * number of up children is greater than halo_max_replicas.
+         * UNLESS you are an SHD in which case do nothing.
          */
         } else if ((child_halo_enabled == _gf_true &&
                         *child_latency_msec <= halo_max_latency_msec) &&
@@ -4358,6 +4367,12 @@ _afr_handle_ping_event (xlator_t *this, xlator_t *child_xlator,
                         *event = GF_EVENT_CHILD_DOWN;
                 }
         }
+
+        if (*event != GF_EVENT_CHILD_PING &&
+            gf_log_get_loglevel () >= GF_LOG_DEBUG) {
+                gf_log (this->name, GF_LOG_DEBUG, "Initial halo states:");
+                dump_halo_states (this);
+        }
 }
 
 void
@@ -4457,6 +4472,11 @@ out:
         }
 
         priv->last_event[idx] = *event;
+
+        if (gf_log_get_loglevel () >= GF_LOG_DEBUG) {
+                gf_log (this->name, GF_LOG_DEBUG, "New halo states:");
+                dump_halo_states (this);
+        }
 }
 
 void
@@ -4551,6 +4571,11 @@ _afr_handle_child_down_event (xlator_t *this, xlator_t *child_xlator,
                 *event = GF_EVENT_CHILD_MODIFIED;
         }
         priv->last_event[idx] = *event;
+
+        if (gf_log_get_loglevel () >= GF_LOG_DEBUG) {
+                gf_log (this->name, GF_LOG_DEBUG, "New halo states:");
+                dump_halo_states (this);
+        }
 }
 
 int64_t