diff --git a/src/pmdas/root/docker.c b/src/pmdas/root/docker.c
index d665a73..ce24ef4 100644
--- a/src/pmdas/root/docker.c
+++ b/src/pmdas/root/docker.c
@@ -174,8 +174,6 @@ docker_values_changed(const char *path, container_t *values)
     return 1;
 }
 
-static int State;
-
 static int
 docker_values_extract(const char *js, jsmntok_t *t, size_t count,
 			int key, container_t *values)
@@ -198,22 +196,27 @@ docker_values_extract(const char *js, jsmntok_t *t, size_t count,
 	    jsmntok_t	*value = t + 1;
 
 	    if (t->parent == 0) {	/* top-level: look for Name & State */
-		if (jsmneq(js, t, "Name") == 0)
+		if (jsmneq(js, t, "Name") == 0) {
 		    jsmnstrdup(js, value, &values->name);
-		if (jsmneq(js, t, "State") == 0)
-		    State = (value->type == JSMN_OBJECT);
+		    values->uptodate++;
+		}
+		if (jsmneq(js, t, "State") == 0) {
+		    values->state = (value->type == JSMN_OBJECT);
+		    values->uptodate++;
+		}
 	    }
-	    else if (State != 0) {	/* pick out various stateful values */
-		int 	*flag = &values->status;
+	    else if (values->state) { /* pick out various stateful values */
+		int 	flag = values->flags;
 
 		if (pmDebug & DBG_TRACE_ATTR)
 		    __pmNotifyErr(LOG_DEBUG, "docker_values_parse: state\n");
+
 		if (jsmneq(js, t, "Running") == 0)
-		    jsmnflag(js, value, flag, CONTAINER_FLAG_RUNNING);
+		    jsmnflag(js, value, &flag, CONTAINER_FLAG_RUNNING);
 		else if (jsmneq(js, t, "Paused") == 0)
-		    jsmnflag(js, value, flag, CONTAINER_FLAG_PAUSED);
+		    jsmnflag(js, value, &flag, CONTAINER_FLAG_PAUSED);
 		else if (jsmneq(js, t, "Restarting") == 0)
-		    jsmnflag(js, value, flag, CONTAINER_FLAG_RESTARTING);
+		    jsmnflag(js, value, &flag, CONTAINER_FLAG_RESTARTING);
 		else if (jsmneq(js, t, "Pid") == 0) {
 		    if (jsmnint(js, value, &values->pid) < 0)
 			values->pid = -1;
@@ -221,6 +224,7 @@ docker_values_extract(const char *js, jsmntok_t *t, size_t count,
 			__pmNotifyErr(LOG_DEBUG, "docker_value PID=%d\n",
 					values->pid);
 		}
+		values->flags = flag;
 	    }
 	}
 	return 1;
@@ -229,7 +233,7 @@ docker_values_extract(const char *js, jsmntok_t *t, size_t count,
 	    j += docker_values_extract(js, t+1+j, count-j, 1, values); /* key */
 	    j += docker_values_extract(js, t+1+j, count-j, 0, values); /*value*/
 	}
-	State = 0;
+	values->state = 0;
 	return j + 1;
     case JSMN_ARRAY:
 	for (i = j = 0; i < t->size; i++)
@@ -264,7 +268,8 @@ docker_values_parse(FILE *fp, const char *name, container_t *values)
 	jslen = 0;
 
     jsmn_init(&p);
-    State = -1;	/* reset State key marker for this iteration */
+    values->uptodate = 0;	/* values for this container not yet visible */
+    values->state = -1;		/* reset State key marker for this iteration */
 
     for (;;) {
 	/* Read another chunk */
@@ -337,7 +342,9 @@ docker_value_refresh(container_engine_t *dp,
 	return -oserror();
     sts = docker_values_parse(fp, name, values);
     fclose(fp);
-    return sts;
+    if (sts < 0)
+	return sts;
+    return values->uptodate == NUM_UPTODATE ? 0 : PM_ERR_AGAIN;
 }
 
 /*
diff --git a/src/pmdas/root/lxc.c b/src/pmdas/root/lxc.c
index 6e79fd0..53c9554 100644
--- a/src/pmdas/root/lxc.c
+++ b/src/pmdas/root/lxc.c
@@ -120,7 +120,7 @@ lxc_values_parse(FILE *pp, const char *name, container_t *values)
     char buffer[256];
     char *s, *key, *value;
 
-    values->pid = values->status = 0;
+    values->pid = values->flags = 0;
 
     while ((s = fgets(buffer, sizeof(buffer)-1, pp)) != NULL) {
 	key = s;
@@ -135,13 +135,14 @@ lxc_values_parse(FILE *pp, const char *name, container_t *values)
 	    if (strncmp(value, "RUNNING", 7) == 0 ||
 	        strncmp(value, "STOPPING", 8) == 0 ||
 	        strncmp(value, "ABORTING", 8) == 0)
-		values->status |= CONTAINER_FLAG_RUNNING;
+		values->flags |= CONTAINER_FLAG_RUNNING;
 	    if (strncmp(value, "STOPPED", 7) == 0)
-		values->status |= CONTAINER_FLAG_PAUSED;
+		values->flags |= CONTAINER_FLAG_PAUSED;
 	    if (strncmp(value, "STARTING", 7) == 0)
-		values->status |= CONTAINER_FLAG_RESTARTING;
+		values->flags |= CONTAINER_FLAG_RESTARTING;
 	}
     }
+    values->uptodate = NUM_UPTODATE;
 
     return 0;
 }
diff --git a/src/pmdas/root/root.c b/src/pmdas/root/root.c
index da96742..1d7208a 100644
--- a/src/pmdas/root/root.c
+++ b/src/pmdas/root/root.c
@@ -112,14 +112,17 @@ root_refresh_container_indom(void)
 	dp->insts_refresh(dp, indom);
 }
 
-static void
+static int
 root_refresh_container_values(char *container, container_t *values)
 {
     container_engine_t *dp;
 
-    for (dp = &engines[0]; dp->name != NULL; dp++)
-	if (values->engine == dp)
-	    dp->value_refresh(dp, container, values);
+    for (dp = &engines[0]; dp->name != NULL; dp++) {
+	if (values->engine != dp)
+	    continue;
+	return dp->value_refresh(dp, container, values);
+    }
+    return PM_ERR_INST;
 }
 
 container_t *
@@ -136,7 +139,8 @@ root_container_search(const char *query)
 	    break;
 	if (!pmdaCacheLookup(indom, inst, &name, (void **)&cp) || !cp)
 	    continue;
-	root_refresh_container_values(name, cp);
+	if (root_refresh_container_values(name, cp) < 0)
+	    continue;
 	for (dp = &engines[0]; dp->name != NULL; dp++) {
 	    if ((fuzzy = dp->name_matching(dp, query, cp->name, name)) <= best)
 		continue;
@@ -193,7 +197,8 @@ root_fetchCallBack(pmdaMetric *mdesc, unsigned int inst, pmAtomValue *atom)
 	    return sts;
 	if (sts != PMDA_CACHE_ACTIVE)
 	    return PM_ERR_INST;
-	root_refresh_container_values(name, cp);
+	if (root_refresh_container_values(name, cp) < 0)
+	    return PM_ERR_INST;
 	switch (idp->item) {
 	case 0:		/* containers.engine */
 	    atom->cp = cp->engine->name;
@@ -205,13 +210,13 @@ root_fetchCallBack(pmdaMetric *mdesc, unsigned int inst, pmAtomValue *atom)
 	    atom->ul = cp->pid;
 	    break;
 	case 3:		/* containers.state.running */
-	    atom->ul = (cp->status & CONTAINER_FLAG_RUNNING) != 0;
+	    atom->ul = (cp->flags & CONTAINER_FLAG_RUNNING) != 0;
 	    break;
 	case 4:		/* containers.state.paused */
-	    atom->ul = (cp->status & CONTAINER_FLAG_PAUSED) != 0;
+	    atom->ul = (cp->flags & CONTAINER_FLAG_PAUSED) != 0;
 	    break;
 	case 5:		/* containers.state.restarting */
-	    atom->ul = (cp->status & CONTAINER_FLAG_RESTARTING) != 0;
+	    atom->ul = (cp->flags & CONTAINER_FLAG_RESTARTING) != 0;
 	    break;
 	default:
 	    return PM_ERR_PMID;
diff --git a/src/pmdas/root/root.h b/src/pmdas/root/root.h
index 2fe3224..9ac0363 100644
--- a/src/pmdas/root/root.h
+++ b/src/pmdas/root/root.h
@@ -29,6 +29,12 @@ enum {
     NUM_METRICS
 };
 
+enum {
+    CONTAINERS_UPTODATE_NAME,
+    CONTAINERS_UPTODATE_STATE,
+    NUM_UPTODATE
+};
+
 /*
  * General container services, abstracting individual implementations into
  * "engines" which are then instantiated one-per-container-technology.
@@ -59,8 +65,11 @@ typedef struct container_engine {
 
 typedef struct container {
     int			pid;
-    int			status;
-    char		*name;
+    int			flags : 8;	/* CONTAINER_FLAG bitwise */
+    int			state : 8;	/* internal driver states */
+    int			uptodate : 8;	/* refreshed values count */ 
+    int			padding : 8;
+    char		*name;		/* human-presentable name */
     char		cgroup[128];
     struct stat		stat;
     container_engine_t	*engine;