Documentation Fix under GroupBy Metrics

docs/operations/metrics.md

@@ -85,6 +85,13 @@ Most metric values reset each emission period, as specified in `druid.monitoring
 |`subquery/fallback/unknownReason/count`|Number of subqueries which cannot be materialized as frames due other reasons.|This metric is only available if the `SubqueryCountStatsMonitor` module is included.| |
 |`query/rowLimit/exceeded/count`|Number of queries whose inlined subquery results exceeded the given row limit|This metric is only available if the `SubqueryCountStatsMonitor` module is included.| |
 |`query/byteLimit/exceeded/count`|Number of queries whose inlined subquery results exceeded the given byte limit|This metric is only available if the `SubqueryCountStatsMonitor` module is included.| |
+|`mergeBuffer/pendingRequests`|Number of requests waiting to acquire a batch of buffers from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Should be ideally 0, though a higher number isn't representative of a problem.|
+|`mergeBuffer/used`|Number of merge buffers used from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Depends on the number of groupBy queries needing merge buffers.|
+|`mergeBuffer/queries`|Number of groupBy queries that acquired a batch of buffers from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Depends on the number of groupBy queries needing merge buffers.|
+|`mergeBuffer/acquisitionTimeNs`|Total time in nanoseconds to acquire merge buffer for groupBy queries.|This metric is only available if the `GroupByStatsMonitor` module is included.|Varies|
+|`groupBy/spilledQueries`|Number of groupBy queries that have spilled onto the disk.|This metric is only available if the `GroupByStatsMonitor` module is included.|Varies|
+|`groupBy/spilledBytes`|Number of bytes spilled on the disk by the groupBy queries.|This metric is only available if the `GroupByStatsMonitor` module is included.|Varies|
+|`groupBy/mergeDictionarySize`|Size of on-heap merge dictionary in bytes.|This metric is only available if the `GroupByStatsMonitor` module is included.|Varies|
 
 ### Historical
 
@@ -102,6 +109,13 @@ Most metric values reset each emission period, as specified in `druid.monitoring
 |`query/failed/count`|Number of failed queries.|This metric is only available if the `QueryCountStatsMonitor` module is included.||
 |`query/interrupted/count`|Number of queries interrupted due to cancellation.|This metric is only available if the `QueryCountStatsMonitor` module is included.||
 |`query/timeout/count`|Number of timed out queries.|This metric is only available if the `QueryCountStatsMonitor` module is included.||
+|`mergeBuffer/pendingRequests`|Number of requests waiting to acquire a batch of buffers from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Should be ideally 0, though a higher number isn't representative of a problem.|
+|`mergeBuffer/used`|Number of merge buffers used from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Depends on the number of groupBy queries needing merge buffers.|
+|`mergeBuffer/queries`|Number of groupBy queries that acquired a batch of buffers from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Depends on the number of groupBy queries needing merge buffers.|
+|`mergeBuffer/acquisitionTimeNs`|Total time in nanoseconds to acquire merge buffer for groupBy queries.|This metric is only available if the `GroupByStatsMonitor` module is included.|Varies|
+|`groupBy/spilledQueries`|Number of groupBy queries that have spilled onto the disk.|This metric is only available if the `GroupByStatsMonitor` module is included.|Varies|
+|`groupBy/spilledBytes`|Number of bytes spilled on the disk by the groupBy queries.|This metric is only available if the `GroupByStatsMonitor` module is included.|Varies|
+|`groupBy/mergeDictionarySize`|Size of on-heap merge dictionary in bytes.|This metric is only available if the `GroupByStatsMonitor` module is included.|Varies|
 
 ### Real-time
 
@@ -117,13 +131,6 @@ Most metric values reset each emission period, as specified in `druid.monitoring
 |`query/failed/count`|Number of failed queries.|This metric is only available if the `QueryCountStatsMonitor` module is included.||
 |`query/interrupted/count`|Number of queries interrupted due to cancellation.|This metric is only available if the `QueryCountStatsMonitor` module is included.||
 |`query/timeout/count`|Number of timed out queries.|This metric is only available if the `QueryCountStatsMonitor` module is included.||
-
-### GroupBy query metrics 
-
-These metrics are reported from broker, historical and real-time nodes 
-
-|Metric|Description|Normal value|
-|------|-----------|------------|
 |`mergeBuffer/pendingRequests`|Number of requests waiting to acquire a batch of buffers from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Should be ideally 0, though a higher number isn't representative of a problem.|
 |`mergeBuffer/used`|Number of merge buffers used from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Depends on the number of groupBy queries needing merge buffers.|
 |`mergeBuffer/queries`|Number of groupBy queries that acquired a batch of buffers from the merge buffer pool.|This metric is only available if the `GroupByStatsMonitor` module is included.|Depends on the number of groupBy queries needing merge buffers.|