X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/6eb3d1fb8fe71623fa63da46c250184cf2e4fbb8..a95f899d7ac84f29b3d019aa410d265bb40833e5:/services/datamanager/summary/pull_list.go

diff --git a/services/datamanager/summary/pull_list.go b/services/datamanager/summary/pull_list.go
index fb1fed17f6..d7fb3eb8f7 100644
--- a/services/datamanager/summary/pull_list.go
+++ b/services/datamanager/summary/pull_list.go
@@ -1,4 +1,5 @@
 // Code for generating pull lists as described in https://arvados.org/projects/arvados/wiki/Keep_Design_Doc#Pull-List
+
 package summary
 
 import (
@@ -8,43 +9,49 @@ import (
 	"git.curoverse.com/arvados.git/sdk/go/keepclient"
 	"git.curoverse.com/arvados.git/sdk/go/logger"
 	"git.curoverse.com/arvados.git/services/datamanager/keep"
-	"git.curoverse.com/arvados.git/services/datamanager/loggerutil"
 	"log"
 	"os"
 	"strings"
 )
 
-type Locator struct {
-	Digest blockdigest.BlockDigest
-	// TODO(misha): Add size field to the Locator (and MarshalJSON() below)
-}
+// Locator is a block digest
+type Locator blockdigest.DigestWithSize
 
+// MarshalJSON encoding
 func (l Locator) MarshalJSON() ([]byte, error) {
-	return []byte("\"" + l.Digest.String() + "\""), nil
+	return []byte("\"" + blockdigest.DigestWithSize(l).String() + "\""), nil
 }
 
-// One entry in the Pull List
-type PullListEntry struct {
+// PullRequest represents one entry in the Pull List
+type PullRequest struct {
 	Locator Locator  `json:"locator"`
 	Servers []string `json:"servers"`
 }
 
-// The Pull List for a particular server
-type PullList struct {
-	Entries []PullListEntry `json:"blocks"`
-}
+// PullList for a particular server
+type PullList []PullRequest
 
-// EntriesByDigest implements sort.Interface for []PullListEntry
-// based on the Digest.
-type EntriesByDigest []PullListEntry
+// PullListByLocator implements sort.Interface for PullList based on
+// the Digest.
+type PullListByLocator PullList
 
-func (a EntriesByDigest) Len() int      { return len(a) }
-func (a EntriesByDigest) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
-func (a EntriesByDigest) Less(i, j int) bool {
+func (a PullListByLocator) Len() int      { return len(a) }
+func (a PullListByLocator) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+func (a PullListByLocator) Less(i, j int) bool {
 	di, dj := a[i].Locator.Digest, a[j].Locator.Digest
-	return di.H < dj.H || (di.H == dj.H && di.L < dj.L)
+	if di.H < dj.H {
+		return true
+	} else if di.H == dj.H {
+		if di.L < dj.L {
+			return true
+		} else if di.L == dj.L {
+			return a[i].Locator.Size < a[j].Locator.Size
+		}
+	}
+	return false
 }
 
+// PullServers struct
 // For a given under-replicated block, this structure represents which
 // servers should pull the specified block and which servers they can
 // pull it from.
@@ -53,53 +60,64 @@ type PullServers struct {
 	From []string // Servers that already contain the specified block
 }
 
-// Creates a map from block locator to PullServers with one entry for
-// each under-replicated block.
+// ComputePullServers creates a map from block locator to PullServers
+// with one entry for each under-replicated block.
+//
+// This method ignores zero-replica blocks since there are no servers
+// to pull them from, so callers should feel free to omit them, but
+// this function will ignore them if they are provided.
 func ComputePullServers(kc *keepclient.KeepClient,
 	keepServerInfo *keep.ReadServers,
-	blockToDesiredReplication map[blockdigest.BlockDigest]int,
+	blockToDesiredReplication map[blockdigest.DigestWithSize]int,
 	underReplicated BlockSet) (m map[Locator]PullServers) {
 	m = map[Locator]PullServers{}
-	// We use CanonicalString to avoid filling memory with dupicate
+	// We use CanonicalString to avoid filling memory with duplicate
 	// copies of the same string.
 	var cs CanonicalString
 
-	for block, _ := range underReplicated {
+	// Servers that are writeable
+	writableServers := map[string]struct{}{}
+	for _, url := range kc.WritableLocalRoots() {
+		writableServers[cs.Get(url)] = struct{}{}
+	}
+
+	for block := range underReplicated {
 		serversStoringBlock := keepServerInfo.BlockToServers[block]
 		numCopies := len(serversStoringBlock)
 		numCopiesMissing := blockToDesiredReplication[block] - numCopies
 		if numCopiesMissing > 0 {
 			// We expect this to always be true, since the block was listed
 			// in underReplicated.
-			// TODO(misha): Consider asserting the above conditional.
 
 			if numCopies > 0 {
-				// I believe that we should expect this to always be true.
+				// Not much we can do with blocks with no copies.
 
 				// A server's host-port string appears as a key in this map
 				// iff it contains the block.
 				serverHasBlock := map[string]struct{}{}
 				for _, info := range serversStoringBlock {
 					sa := keepServerInfo.KeepServerIndexToAddress[info.ServerIndex]
-					serverHasBlock[sa.HostPort()] = struct{}{}
+					serverHasBlock[cs.Get(sa.URL())] = struct{}{}
 				}
 
-				roots := keepclient.NewRootSorter(kc.ServiceRoots(),
+				roots := keepclient.NewRootSorter(kc.LocalRoots(),
 					block.String()).GetSortedRoots()
 
-				l := Locator{Digest: block}
-				m[l] = CreatePullServers(cs, serverHasBlock, roots, numCopiesMissing)
+				l := Locator(block)
+				m[l] = CreatePullServers(cs, serverHasBlock, writableServers,
+					roots, numCopiesMissing)
 			}
 		}
 	}
 	return m
 }
 
-// Creates a pull list in which the To and From fields preserve the
-// ordering of sorted servers and the contents are all canonical
-// strings.
+// CreatePullServers creates a pull list in which the To and From
+// fields preserve the ordering of sorted servers and the contents
+// are all canonical strings.
 func CreatePullServers(cs CanonicalString,
 	serverHasBlock map[string]struct{},
+	writableServers map[string]struct{},
 	sortedServers []string,
 	maxToFields int) (ps PullServers) {
 
@@ -111,24 +129,28 @@ func CreatePullServers(cs CanonicalString,
 	for _, host := range sortedServers {
 		// Strip the protocol portion of the url.
 		// Use the canonical copy of the string to avoid memory waste.
-		server := cs.Get(RemoveProtocolPrefix(host))
+		server := cs.Get(host)
 		_, hasBlock := serverHasBlock[server]
 		if hasBlock {
-			ps.From = append(ps.From, server)
+			// The from field should include the protocol.
+			ps.From = append(ps.From, cs.Get(host))
 		} else if len(ps.To) < maxToFields {
-			ps.To = append(ps.To, server)
+			_, writable := writableServers[host]
+			if writable {
+				ps.To = append(ps.To, server)
+			}
 		}
 	}
 
 	return
 }
 
-// Strips the protocol prefix from a url.
+// RemoveProtocolPrefix strips the protocol prefix from a url.
 func RemoveProtocolPrefix(url string) string {
 	return url[(strings.LastIndex(url, "/") + 1):]
 }
 
-// Produces a PullList for each keep server.
+// BuildPullLists produces a PullList for each keep server.
 func BuildPullLists(lps map[Locator]PullServers) (spl map[string]PullList) {
 	spl = map[string]PullList{}
 	// We don't worry about canonicalizing our strings here, because we
@@ -138,40 +160,56 @@ func BuildPullLists(lps map[Locator]PullServers) (spl map[string]PullList) {
 		for _, destination := range pullServers.To {
 			pullList, pullListExists := spl[destination]
 			if !pullListExists {
-				pullList = PullList{Entries: []PullListEntry{}}
-				spl[destination] = pullList
+				pullList = PullList{}
 			}
-			pullList.Entries = append(pullList.Entries,
-				PullListEntry{Locator: locator, Servers: pullServers.From})
-			spl[destination] = pullList
+			spl[destination] = append(pullList,
+				PullRequest{Locator: locator, Servers: pullServers.From})
 		}
 	}
 	return
 }
 
-// Writes each pull list to a file.
+// WritePullLists writes each pull list to a file.
 // The filename is based on the hostname.
 //
 // This is just a hack for prototyping, it is not expected to be used
 // in production.
 func WritePullLists(arvLogger *logger.Logger,
-	pullLists map[string]PullList) {
+	pullLists map[string]PullList,
+	dryRun bool) error {
 	r := strings.NewReplacer(":", ".")
+
 	for host, list := range pullLists {
-		filename := fmt.Sprintf("pull_list.%s", r.Replace(host))
+		if arvLogger != nil {
+			// We need a local variable because Update doesn't call our mutator func until later,
+			// when our list variable might have been reused by the next loop iteration.
+			host := host
+			listLen := len(list)
+			arvLogger.Update(func(p map[string]interface{}, e map[string]interface{}) {
+				pullListInfo := logger.GetOrCreateMap(p, "pull_list_len")
+				pullListInfo[host] = listLen
+			})
+		}
+
+		if dryRun {
+			log.Print("dry run, not sending pull list to service %s with %d blocks", host, len(list))
+			continue
+		}
+
+		filename := fmt.Sprintf("pull_list.%s", r.Replace(RemoveProtocolPrefix(host)))
 		pullListFile, err := os.Create(filename)
 		if err != nil {
-			loggerutil.FatalWithMessage(arvLogger,
-				fmt.Sprintf("Failed to open %s: %v", filename, err))
+			return err
 		}
 		defer pullListFile.Close()
 
 		enc := json.NewEncoder(pullListFile)
 		err = enc.Encode(list)
 		if err != nil {
-			loggerutil.FatalWithMessage(arvLogger,
-				fmt.Sprintf("Failed to write pull list to %s: %v", filename, err))
+			return err
 		}
 		log.Printf("Wrote pull list to %s.", filename)
 	}
+
+	return nil
 }