From: Dan van der Ster <daniel.vanderster@cern.ch>
Date: Tue, 29 Jun 2021 20:36:00 +0000 (+0200)
Subject: mgr/DaemonServer: skip redundant update of pgp_num_actual
X-Git-Tag: v16.2.6~145^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F42223%2Fhead;p=ceph.git

mgr/DaemonServer: skip redundant update of pgp_num_actual

During PG merge the MGR was observed repeatedly sending identical
set pgp_num_actual values, leading to osdmap churn at 2000/hr.

Skip the redundant osd set pgp_num_actual command if the
pgp_num is already our computed next.

Fixes: https://tracker.ceph.com/issues/51433
Signed-off-by: Dan van der Ster <daniel.vanderster@cern.ch>
(cherry picked from commit 3f15749de0d550a124f8c6afbd457f17ef020963)
---

diff --git a/src/mgr/DaemonServer.cc b/src/mgr/DaemonServer.cc
index 48816578ccb5..48534f896ac4 100644
--- a/src/mgr/DaemonServer.cc
+++ b/src/mgr/DaemonServer.cc
@@ -2867,11 +2867,13 @@ void DaemonServer::adjust_pgs()
 		}
 	      }
 	    }
-	    dout(10) << "pool " << i.first
-		     << " pgp_num_target " << p.get_pgp_num_target()
-		     << " pgp_num " << p.get_pgp_num()
-		     << " -> " << next << dendl;
-	    pgp_num_to_set[osdmap.get_pool_name(i.first)] = next;
+	    if (next != p.get_pgp_num()) {
+	      dout(10) << "pool " << i.first
+		       << " pgp_num_target " << p.get_pgp_num_target()
+		       << " pgp_num " << p.get_pgp_num()
+		       << " -> " << next << dendl;
+	      pgp_num_to_set[osdmap.get_pool_name(i.first)] = next;
+	    }
 	  }
 	}
 	if (left == 0) {