Merge pull request #238 from grafana/add-bucket-index-observability

Add bucket index observability

Author: pracucci

CHANGELOG.md

@@ -3,6 +3,9 @@
 ## master / unreleased
 
 * [ENHANCEMENT] Added `unregister_ingesters_on_shutdown` config option to disable unregistering ingesters on shutdown (default is enabled). #213
+* [ENHANCEMENT] Improved blocks storage observability: #237
+  - Cortex / Queries: added bucket index load operations and latency (available only when bucket index is enabled)
+  - Alerts: added "CortexBucketIndexNotUpdated" (bucket index only) and "CortexTenantHasPartialBlocks"
 
 ## 1.6.0 / 2021-01-05
 

cortex-mixin/alerts/blocks.libsonnet

@@ -184,6 +184,33 @@
             message: 'Cortex Store Gateway {{ $labels.namespace }}/{{ $labels.instance }} has not successfully synched the bucket since {{ $value | humanizeDuration }}.',
           },
         },
+        {
+          // Alert if the bucket index has not been updated for a given user.
+          alert: 'CortexBucketIndexNotUpdated',
+          expr: |||
+            min by(namespace, user) (time() - cortex_bucket_index_last_successful_update_timestamp_seconds) > 7200
+          |||,
+          labels: {
+            severity: 'critical',
+          },
+          annotations: {
+            message: 'Cortex bucket index for tenant {{ $labels.user }} in {{ $labels.namespace }} has not been updated since {{ $value | humanizeDuration }}.',
+          },
+        },
+        {
+          // Alert if a we consistently find partial blocks for a given tenant over a relatively large time range.
+          alert: 'CortexTenantHasPartialBlocks',
+          'for': '6h',
+          expr: |||
+            max by(namespace, user) (cortex_bucket_blocks_partials_count) > 0
+          |||,
+          labels: {
+            severity: 'warning',
+          },
+          annotations: {
+            message: 'Cortex tenant {{ $labels.user }} in {{ $labels.namespace }} has {{ $value }} partial blocks.',
+          },
+        },
       ],
     },
   ],

cortex-mixin/dashboards/queries.libsonnet

@@ -136,7 +136,7 @@ local utils = import 'mixin-utils/utils.libsonnet';
       )
     )
     .addRowIf(
-      std.member($._config.storage_engine, 'chunks'),
+      std.member($._config.storage_engine, 'blocks'),
       $.row('Querier - Blocks storage')
       .addPanel(
         $.panel('Number of store-gateways hit per Query') +
@@ -156,7 +156,31 @@ local utils = import 'mixin-utils/utils.libsonnet';
     )
     .addRowIf(
       std.member($._config.storage_engine, 'blocks'),
-      $.row('Store-gateway - Blocks')
+      $.row('')
+      .addPanel(
+        $.panel('Bucket indexes loaded (per querier)') +
+        $.queryPanel([
+          'max(cortex_bucket_index_loaded{%s})' % $.jobMatcher($._config.job_names.querier),
+          'min(cortex_bucket_index_loaded{%s})' % $.jobMatcher($._config.job_names.querier),
+          'avg(cortex_bucket_index_loaded{%s})' % $.jobMatcher($._config.job_names.querier),
+        ], ['Max', 'Min', 'Average']) +
+        { yaxes: $.yaxes('short') },
+      )
+      .addPanel(
+        $.successFailurePanel(
+          'Bucket indexes load / sec',
+          'sum(rate(cortex_bucket_index_loads_total{%s}[$__rate_interval])) - sum(rate(cortex_bucket_index_load_failures_total{%s}[$__rate_interval]))' % [$.jobMatcher($._config.job_names.querier), $.jobMatcher($._config.job_names.querier)],
+          'sum(rate(cortex_bucket_index_load_failures_total{%s}[$__rate_interval]))' % $.jobMatcher($._config.job_names.querier),
+        )
+      )
+      .addPanel(
+        $.panel('Bucket indexes load latency') +
+        $.latencyPanel('cortex_bucket_index_load_duration_seconds', '{%s}' % $.jobMatcher($._config.job_names.querier)),
+      )
+    )
+    .addRowIf(
+      std.member($._config.storage_engine, 'blocks'),
+      $.row('Store-gateway - Blocks storage')
       .addPanel(
         $.panel('Blocks queried / sec') +
         $.queryPanel('sum(rate(cortex_bucket_store_series_blocks_queried_sum{component="store-gateway",%s}[$__rate_interval]))' % $.jobMatcher($._config.job_names.store_gateway), 'blocks') +

cortex-mixin/docs/playbooks.md

@@ -226,6 +226,28 @@ gsutil mv gs://BUCKET/TENANT/BLOCK gs://BUCKET/TENANT/corrupted-BLOCK
 
 Same as [`CortexCompactorHasNotUploadedBlocks`](#CortexCompactorHasNotUploadedBlocks).
 
+### CortexBucketIndexNotUpdated
+
+This alert fires when the bucket index, for a given tenant, is not updated since a long time. The bucket index is expected to be periodically updated by the compactor and is used by queriers and store-gateways to get an almost-updated view over the bucket store. 
+
+How to **investigate**:
+- Ensure the compactor is successfully running
+- Look for any error in the compactor logs
+
+### CortexTenantHasPartialBlocks
+
+This alert fires when Cortex finds partial blocks for a given tenant. A partial block is a block missing the `meta.json` and this may usually happen in two circumstances:
+
+1. A block upload has been interrupted and not cleaned up or retried
+2. A block deletion has been interrupted and `deletion-mark.json` has been deleted before `meta.json`
+
+How to **investigate**:
+- Look for the block ID in the logs
+- Find out which Cortex component operated on the block at last (eg. uploaded by ingester/compactor, or deleted by compactor)
+- Investigate if was a partial upload or partial delete
+- Safely manually delete the block from the bucket if was a partial delete or an upload failed by a compactor
+- Further investigate if was an upload failed by an ingester but not later retried (ingesters are expected to retry uploads until succeed)
+
 ### CortexWALCorruption
 
 This alert is only related to the chunks storage. This can happen because of 2 reasons: (1) Non graceful shutdown of ingesters. (2) Faulty storage or NFS.