Get rid of absent() function in legacy Ceph dashboards

Change-Id: I363b3951a0116667b5bf0d1557bd27373da46f21
Related-PROD: PROD-28123 (PROD:28123)
diff --git a/ceph/files/grafana_dashboards/legacy/ceph_cluster_prometheus.json b/ceph/files/grafana_dashboards/legacy/ceph_cluster_prometheus.json
index eb1fe5c..211509e 100644
--- a/ceph/files/grafana_dashboards/legacy/ceph_cluster_prometheus.json
+++ b/ceph/files/grafana_dashboards/legacy/ceph_cluster_prometheus.json
@@ -1328,7 +1328,7 @@
           "steppedLine": false,
           "targets": [
             {
-              "expr": "ceph_pgmap_write_op_per_sec or absent(ceph_pgmap_write_op_per_sec) - 1",
+              "expr": "avg(ceph_pgmap_write_op_per_sec)",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -1337,7 +1337,7 @@
               "step": 60
             },
             {
-              "expr": "ceph_pgmap_read_op_per_sec or absent(ceph_pgmap_read_op_per_sec) - 1",
+              "expr": "avg(ceph_pgmap_read_op_per_sec)",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -1421,7 +1421,7 @@
           "steppedLine": false,
           "targets": [
             {
-              "expr": "ceph_pgmap_write_bytes_sec or absent(ceph_pgmap_write_bytes_sec) - 1 ",
+              "expr": "avg(ceph_pgmap_write_bytes_sec)",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -1430,7 +1430,7 @@
               "step": 60
             },
             {
-              "expr": "ceph_pgmap_read_bytes_sec or absent(ceph_pgmap_read_bytes_sec) - 1",
+              "expr": "avg(ceph_pgmap_read_bytes_sec)",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -1637,7 +1637,7 @@
           "linewidth": 0,
           "links": [],
           "minSpan": null,
-          "nullPointMode": "connected",
+          "nullPointMode": "null as zero",
           "percentage": false,
           "pointradius": 5,
           "points": false,
@@ -1656,7 +1656,7 @@
           "steppedLine": false,
           "targets": [
             {
-              "expr": "ceph_usage_total_bytes - ceph_usage_total_used_bytes",
+              "expr": "avg(ceph_usage_total_bytes - ceph_usage_total_used_bytes)",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -1665,7 +1665,7 @@
               "step": 60
             },
             {
-              "expr": "ceph_usage_total_used_bytes or absent(ceph_usage_total_used_bytes) - 1",
+              "expr": "avg(ceph_usage_total_used_bytes)",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -1674,7 +1674,7 @@
               "step": 60
             },
             {
-              "expr": "ceph_usage_total_bytes or absent(ceph_usage_total_bytes) - 1",
+              "expr": "avg(ceph_usage_total_bytes)",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
diff --git a/ceph/files/grafana_dashboards/legacy/ceph_pools_prometheus.json b/ceph/files/grafana_dashboards/legacy/ceph_pools_prometheus.json
index a669b33..1c402e0 100644
--- a/ceph/files/grafana_dashboards/legacy/ceph_pools_prometheus.json
+++ b/ceph/files/grafana_dashboards/legacy/ceph_pools_prometheus.json
@@ -437,7 +437,7 @@
           "steppedLine": false,
           "targets": [
             {
-              "expr": "avg(irate(ceph_pool_stats_read_op_per_sec{name=\"$pool\"}[3m])) or absent(avg(irate(ceph_pool_stats_read_op_per_sec{name=\"$pool\"}[3m]))) - 1",
+              "expr": "avg(irate(ceph_pool_stats_read_op_per_sec{name=\"$pool\"}[3m]))",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -446,7 +446,7 @@
               "step": 60
             },
             {
-              "expr": "avg(irate(ceph_pool_stats_write_op_per_sec{name=\"$pool\"}[3m])) or absent(avg(irate(ceph_pool_stats_write_op_per_sec{name=\"$pool\"}[3m]))) - 1",
+              "expr": "avg(irate(ceph_pool_stats_write_op_per_sec{name=\"$pool\"}[3m]))",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -530,7 +530,7 @@
           "steppedLine": false,
           "targets": [
             {
-              "expr": "avg(irate(ceph_pool_stats_read_bytes_sec{name=\"$pool\"}[3m])) or absent(irate(ceph_pool_stats_read_bytes_sec{name=\"$pool\"}[3m])) - 1",
+              "expr": "avg(irate(ceph_pool_stats_read_bytes_sec{name=\"$pool\"}[3m]))",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,
@@ -539,7 +539,7 @@
               "step": 60
             },
             {
-              "expr": "avg(irate(ceph_pool_stats_write_bytes_sec{name=\"$pool\"}[3m])) or absent(irate(ceph_pool_stats_write_bytes_sec{name=\"$pool\"}[3m])) - 1 ",
+              "expr": "avg(irate(ceph_pool_stats_write_bytes_sec{name=\"$pool\"}[3m]))",
               "format": "time_series",
               "interval": "",
               "intervalFactor": 1,