diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 6bc1a6b46d..d18a251d51 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2564,6 +2564,12 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible)
 						RequestCheckpoint(CHECKPOINT_CAUSE_XLOG);
 				}
 			}
+
+			if (finishing_seg &&
+				!last_iteration &&
+				random() < 0.25 * MAX_RANDOM_VALUE)
+				ereport(PANIC,
+						(errmsg("failing at inconvenient time")));
 		}
 
 		if (ispartialpage)
diff --git a/src/backend/access/transam/xlogarchive.c b/src/backend/access/transam/xlogarchive.c
index e14bcf8ea6..8ae533fea6 100644
--- a/src/backend/access/transam/xlogarchive.c
+++ b/src/backend/access/transam/xlogarchive.c
@@ -511,10 +511,19 @@ void
 XLogArchiveNotify(const char *xlog)
 {
 	char		archiveStatusPath[MAXPGPATH];
+	char		archiveStatusDonePath[MAXPGPATH];
 	FILE	   *fd;
 
 	/* insert an otherwise empty file called <XLOG>.ready */
 	StatusFilePath(archiveStatusPath, xlog, ".ready");
+	StatusFilePath(archiveStatusDonePath, xlog, ".done");
+
+	if (access(archiveStatusPath, F_OK) == 0 ||
+		access(archiveStatusDonePath, F_OK) == 0)
+		ereport(LOG,
+				(errmsg("status file already exists for \"%s\"",
+						xlog)));
+
 	fd = AllocateFile(archiveStatusPath, "w");
 	if (fd == NULL)
 	{