docs: Mention the dependecy on the compactor feature flag (#4302)

Author: simonswine

cmd/pyroscope/help-all.txt.tmpl

@@ -36,7 +36,7 @@ Usage of ./pyroscope:
   -compactor.compaction-split-by string
     	Experimental: The strategy to use when splitting blocks during compaction. Supported values are: fingerprint, stacktracePartition. (default "fingerprint")
   -compactor.compactor-downsampler-enabled
-    	If enabled, the compactor will downsample profiles in blocks at compaction level 3 and above. The original profiles are also kept. (default true)
+    	If enabled, the compactor will downsample profiles in blocks at compaction level 3 and above. The original profiles are also kept. Note: This set the default for the teanant overrides, in order to be effective it also requires compactor.downsampler-enabled to be set to true. (default true)
   -compactor.compactor-tenant-shard-size int
     	Max number of compactors that can compact blocks for single tenant. 0 to disable the limit and use all compactors.
   -compactor.data-dir string

cmd/pyroscope/help.txt.tmpl

@@ -8,7 +8,7 @@ Usage of ./pyroscope:
   -compactor.blocks-retention-period duration
     	Delete blocks containing samples older than the specified retention period. 0 to disable.
   -compactor.compactor-downsampler-enabled
-    	If enabled, the compactor will downsample profiles in blocks at compaction level 3 and above. The original profiles are also kept. (default true)
+    	If enabled, the compactor will downsample profiles in blocks at compaction level 3 and above. The original profiles are also kept. Note: This set the default for the teanant overrides, in order to be effective it also requires compactor.downsampler-enabled to be set to true. (default true)
   -compactor.compactor-tenant-shard-size int
     	Max number of compactors that can compact blocks for single tenant. 0 to disable the limit and use all compactors.
   -compactor.data-dir string

docs/sources/configure-server/reference-configuration-parameters/index.md

@@ -2215,7 +2215,9 @@ distributor_usage_groups:
 [compactor_partial_block_deletion_delay: <duration> | default = 1d]
 
 # If enabled, the compactor will downsample profiles in blocks at compaction
-# level 3 and above. The original profiles are also kept.
+# level 3 and above. The original profiles are also kept. Note: This set the
+# default for the teanant overrides, in order to be effective it also requires
+# compactor.downsampler-enabled to be set to true.
 # CLI flag: -compactor.compactor-downsampler-enabled
 [compactor_downsampler_enabled: <boolean> | default = true]
 

pkg/validation/limits.go

@@ -192,7 +192,7 @@ func (l *Limits) RegisterFlags(f *flag.FlagSet) {
 	f.IntVar(&l.CompactorTenantShardSize, "compactor.compactor-tenant-shard-size", 0, "Max number of compactors that can compact blocks for single tenant. 0 to disable the limit and use all compactors.")
 	_ = l.CompactorPartialBlockDeletionDelay.Set("1d")
 	f.Var(&l.CompactorPartialBlockDeletionDelay, "compactor.partial-block-deletion-delay", fmt.Sprintf("If a partial block (unfinished block without %s file) hasn't been modified for this time, it will be marked for deletion. The minimum accepted value is %s: a lower value will be ignored and the feature disabled. 0 to disable.", block.MetaFilename, MinCompactorPartialBlockDeletionDelay.String()))
-	f.BoolVar(&l.CompactorDownsamplerEnabled, "compactor.compactor-downsampler-enabled", true, "If enabled, the compactor will downsample profiles in blocks at compaction level 3 and above. The original profiles are also kept.")
+	f.BoolVar(&l.CompactorDownsamplerEnabled, "compactor.compactor-downsampler-enabled", true, "If enabled, the compactor will downsample profiles in blocks at compaction level 3 and above. The original profiles are also kept. Note: This set the default for the teanant overrides, in order to be effective it also requires compactor.downsampler-enabled to be set to true.")
 
 	_ = l.RejectNewerThan.Set("10m")
 	f.Var(&l.RejectNewerThan, "validation.reject-newer-than", "This limits how far into the future profiling data can be ingested. This limit is enforced in the distributor. 0 to disable, defaults to 10m.")