Simplify compactor alerts

We should simply alert on things not having run since X.

Signed-off-by: Goutham Veeramachaneni <[email protected]>

Author: gouthamve

cortex-mixin/alerts/compactor.libsonnet

@@ -6,11 +6,9 @@
         {
           // Alert if the compactor has not successfully cleaned up blocks in the last 24h.
           alert: 'CortexCompactorHasNotSuccessfullyCleanedUpBlocks',
-          'for': '15m',
+          'for': '1h',
           expr: |||
             (time() - cortex_compactor_block_cleanup_last_successful_run_timestamp_seconds > 60 * 60 * 24)
-            and
-            (cortex_compactor_block_cleanup_last_successful_run_timestamp_seconds > 0)
           |||,
           labels: {
             severity: 'critical',
@@ -20,17 +18,17 @@
           },
         },
         {
-          // Alert if the compactor has not successfully cleaned up blocks since its start.
-          alert: 'CortexCompactorHasNotSuccessfullyCleanedUpBlocksSinceStart',
-          'for': '24h',
+          // Alert if the compactor has not successfully run compaction in the last 6h.
+          alert: 'CortexCompactorHasNotSuccessfullyRunCompaction',
+          'for': '1h',
           expr: |||
-            cortex_compactor_block_cleanup_last_successful_run_timestamp_seconds == 0
+            time() - cortex_compactor_block_cleanup_last_successful_run_timestamp_seconds > 60 * 60 * 6
           |||,
           labels: {
             severity: 'critical',
           },
           annotations: {
-            message: 'Cortex Compactor {{ $labels.namespace }}/{{ $labels.instance }} has not successfully cleaned up blocks in the last 24 hours.',
+            message: 'Cortex Compactor {{ $labels.namespace }}/{{ $labels.instance }} has not run compaction in the last 6 hours.',
           },
         },
         {