6260: Remove test for impossible condition.
[arvados.git] / services / datamanager / summary / summary.go
index 37e9373969efb826ba5c9f1efb895937f892df3f..edd760b035d066627b51f913799bb2606f4c0141 100644 (file)
@@ -8,19 +8,30 @@ import (
        "git.curoverse.com/arvados.git/sdk/go/blockdigest"
        "git.curoverse.com/arvados.git/services/datamanager/collection"
        "git.curoverse.com/arvados.git/services/datamanager/keep"
+       "sort"
 )
 
-type BlockSet map[blockdigest.BlockDigest]struct{}
+type BlockSet map[blockdigest.DigestWithSize]struct{}
 
-func (bs BlockSet) Insert(digest blockdigest.BlockDigest) {
+// Adds a single block to the set.
+func (bs BlockSet) Insert(digest blockdigest.DigestWithSize) {
        bs[digest] = struct{}{}
 }
 
+// Adds a set of blocks to the set.
+func (bs BlockSet) Union(obs BlockSet) {
+       for k, v := range obs {
+               bs[k] = v
+       }
+}
+
 // We use the collection index to save space. To convert to and from
 // the uuid, use collection.ReadCollections' fields
 // CollectionIndexToUuid and CollectionUuidToIndex.
 type CollectionIndexSet map[int]struct{}
 
+// Adds a single collection to the set. The collection is specified by
+// its index.
 func (cis CollectionIndexSet) Insert(collectionIndex int) {
        cis[collectionIndex] = struct{}{}
 }
@@ -29,12 +40,37 @@ func (bs BlockSet) ToCollectionIndexSet(
        readCollections collection.ReadCollections,
        collectionIndexSet *CollectionIndexSet) {
        for block := range bs {
-               for _,collectionIndex := range readCollections.BlockToCollectionIndices[block] {
+               for _, collectionIndex := range readCollections.BlockToCollectionIndices[block] {
                        collectionIndexSet.Insert(collectionIndex)
                }
        }
 }
 
+// Keeps track of the requested and actual replication levels.
+// Currently this is only used for blocks but could easily be used for
+// collections as well.
+type ReplicationLevels struct {
+       // The requested replication level.
+       // For Blocks this is the maximum replication level among all the
+       // collections this block belongs to.
+       Requested int
+
+       // The actual number of keep servers this is on.
+       Actual int
+}
+
+// Maps from replication levels to their blocks.
+type ReplicationLevelBlockSetMap map[ReplicationLevels]BlockSet
+
+// An individual entry from ReplicationLevelBlockSetMap which only reports the number of blocks, not which blocks.
+type ReplicationLevelBlockCount struct {
+       Levels ReplicationLevels
+       Count  int
+}
+
+// An ordered list of ReplicationLevelBlockCount useful for reporting.
+type ReplicationLevelBlockSetSlice []ReplicationLevelBlockCount
+
 type ReplicationSummary struct {
        CollectionBlocksNotInKeep  BlockSet
        UnderReplicatedBlocks      BlockSet
@@ -61,9 +97,66 @@ type ReplicationSummaryCounts struct {
        CorrectlyReplicatedCollections int
 }
 
+// Gets the BlockSet for a given set of ReplicationLevels, creating it
+// if it doesn't already exist.
+func (rlbs ReplicationLevelBlockSetMap) GetOrCreate(
+       repLevels ReplicationLevels) (bs BlockSet) {
+       bs, exists := rlbs[repLevels]
+       if !exists {
+               bs = make(BlockSet)
+               rlbs[repLevels] = bs
+       }
+       return
+}
+
+// Adds a block to the set for a given replication level.
+func (rlbs ReplicationLevelBlockSetMap) Insert(
+       repLevels ReplicationLevels,
+       block blockdigest.DigestWithSize) {
+       rlbs.GetOrCreate(repLevels).Insert(block)
+}
+
+// Adds a set of blocks to the set for a given replication level.
+func (rlbs ReplicationLevelBlockSetMap) Union(
+       repLevels ReplicationLevels,
+       bs BlockSet) {
+       rlbs.GetOrCreate(repLevels).Union(bs)
+}
+
+// Outputs a sorted list of ReplicationLevelBlockCounts.
+func (rlbs ReplicationLevelBlockSetMap) Counts() (
+       sorted ReplicationLevelBlockSetSlice) {
+       sorted = make(ReplicationLevelBlockSetSlice, len(rlbs))
+       i := 0
+       for levels, set := range rlbs {
+               sorted[i] = ReplicationLevelBlockCount{Levels: levels, Count: len(set)}
+               i++
+       }
+       sort.Sort(sorted)
+       return
+}
+
+// Implemented to meet sort.Interface
+func (rlbss ReplicationLevelBlockSetSlice) Len() int {
+       return len(rlbss)
+}
+
+// Implemented to meet sort.Interface
+func (rlbss ReplicationLevelBlockSetSlice) Less(i, j int) bool {
+       return rlbss[i].Levels.Requested < rlbss[j].Levels.Requested ||
+               (rlbss[i].Levels.Requested == rlbss[j].Levels.Requested &&
+                       rlbss[i].Levels.Actual < rlbss[j].Levels.Actual)
+}
+
+// Implemented to meet sort.Interface
+func (rlbss ReplicationLevelBlockSetSlice) Swap(i, j int) {
+       rlbss[i], rlbss[j] = rlbss[j], rlbss[i]
+}
+
 func (rs ReplicationSummary) ComputeCounts() (rsc ReplicationSummaryCounts) {
-       // TODO(misha): Consider replacing this brute-force approach by
-       // iterating through the fields using reflection.
+       // TODO(misha): Consider rewriting this method to iterate through
+       // the fields using reflection, instead of explictily listing the
+       // fields as we do now.
        rsc.CollectionBlocksNotInKeep = len(rs.CollectionBlocksNotInKeep)
        rsc.UnderReplicatedBlocks = len(rs.UnderReplicatedBlocks)
        rsc.OverReplicatedBlocks = len(rs.OverReplicatedBlocks)
@@ -99,34 +192,53 @@ func (rsc ReplicationSummaryCounts) PrettyPrint() string {
                rsc.CorrectlyReplicatedCollections)
 }
 
-func SummarizeReplication(readCollections collection.ReadCollections,
-       keepServerInfo keep.ReadServers) (rs ReplicationSummary) {
+func BucketReplication(readCollections collection.ReadCollections,
+       keepServerInfo keep.ReadServers) (rlbsm ReplicationLevelBlockSetMap) {
+       rlbsm = make(ReplicationLevelBlockSetMap)
+
+       for block, requestedReplication := range readCollections.BlockToDesiredReplication {
+               rlbsm.Insert(
+                       ReplicationLevels{
+                               Requested: requestedReplication,
+                               Actual:    len(keepServerInfo.BlockToServers[block])},
+                       block)
+       }
+
+       for block, servers := range keepServerInfo.BlockToServers {
+               if 0 == readCollections.BlockToDesiredReplication[block] {
+                       rlbsm.Insert(
+                               ReplicationLevels{Requested: 0, Actual: len(servers)},
+                               block)
+               }
+       }
+       return
+}
+
+func (rlbsm ReplicationLevelBlockSetMap) SummarizeBuckets(
+       readCollections collection.ReadCollections) (
+       rs ReplicationSummary) {
        rs.CollectionBlocksNotInKeep = make(BlockSet)
        rs.UnderReplicatedBlocks = make(BlockSet)
        rs.OverReplicatedBlocks = make(BlockSet)
        rs.CorrectlyReplicatedBlocks = make(BlockSet)
        rs.KeepBlocksNotInCollections = make(BlockSet)
+
        rs.CollectionsNotFullyInKeep = make(CollectionIndexSet)
        rs.UnderReplicatedCollections = make(CollectionIndexSet)
        rs.OverReplicatedCollections = make(CollectionIndexSet)
        rs.CorrectlyReplicatedCollections = make(CollectionIndexSet)
 
-       for block, requestedReplication := range readCollections.BlockToReplication {
-               actualReplication := len(keepServerInfo.BlockToServers[block])
-               if actualReplication == 0 {
-                       rs.CollectionBlocksNotInKeep.Insert(block)
-               } else if actualReplication < requestedReplication {
-                       rs.UnderReplicatedBlocks.Insert(block)
-               } else if actualReplication > requestedReplication {
-                       rs.OverReplicatedBlocks.Insert(block)
+       for levels, bs := range rlbsm {
+               if levels.Actual == 0 {
+                       rs.CollectionBlocksNotInKeep.Union(bs)
+               } else if levels.Requested == 0 {
+                       rs.KeepBlocksNotInCollections.Union(bs)
+               } else if levels.Actual < levels.Requested {
+                       rs.UnderReplicatedBlocks.Union(bs)
+               } else if levels.Actual > levels.Requested {
+                       rs.OverReplicatedBlocks.Union(bs)
                } else {
-                       rs.CorrectlyReplicatedBlocks.Insert(block)
-               }
-       }
-
-       for block, _ := range keepServerInfo.BlockToServers {
-               if 0 == readCollections.BlockToReplication[block] {
-                       rs.KeepBlocksNotInCollections.Insert(block)
+                       rs.CorrectlyReplicatedBlocks.Union(bs)
                }
        }
 
@@ -151,5 +263,5 @@ func SummarizeReplication(readCollections collection.ReadCollections,
                }
        }
 
-       return rs
+       return
 }