prometheus: commit production alert configuration

roles/prometheus/templates/postgres.rules.yml.j2

@@ -112,7 +112,7 @@ groups:
             rate(pg_stat_database_xact_rollback{datname!~"template.*"}[3m]) /
             rate(pg_stat_database_xact_commit{datname!~"template.*"}[3m])
           ) * 100 
-          > 7
+          > 20
         for: 0m
         labels:
           severity: warning

roles/prometheus/templates/server.rules.yml.j2

@@ -10,23 +10,17 @@ groups:
   - name: server.rules
     rules:
 
-      - alert: InstanceDown
+      - alert: MachineDown
         expr: up{instance!~".*.borne.auro.re$"} == 0
         for: 3m
         labels:
           severity: critical
-        annotations:
-          summary: >-
-            Invisible depuis plus de 3 minutes
 
       - alert: AccessPointDown
         expr: up{instance=~".*.borne.auro.re$"} == 0
         for: 3m
         labels:
           severity: warning
-        annotations:
-          summary: >-
-            Invisible depuis plus de 3 minutes
 
       - alert: OutOfMemory
         expr: >-
@@ -50,7 +44,7 @@ groups:
               node_memory_SwapFree_bytes
               / node_memory_SwapTotal_bytes
             )
-          ) * 100 >= 20
+          ) * 100 >= 50
         for: 3m
         labels:
           severity: warning