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initial work for more incremental, less read intensive single jobs

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commit 2d6b40c7507202b3d95e1f154c4d5b4b6a5afb05 1 parent 0633a85
@freels freels authored
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67 src/main/scala/com/twitter/flockdb/jobs/single/Single.scala
@@ -57,6 +57,7 @@ extends JsonJobParser {
Time.fromSeconds(casted("updated_at").toInt),
forwardingManager,
uuidGenerator,
+ casted.get("wrote_forward_direction") map { case b: Boolean => b == true } getOrElse(false),
writeSuccesses.toList
)
}
@@ -71,27 +72,22 @@ class Single(
updatedAt: Time,
forwardingManager: ForwardingManager,
uuidGenerator: UuidGenerator,
- var successes: List[ShardId] = Nil)
+ var wroteForwardDirection: Boolean = false,
+ var successes: List[ShardId] = Nil
+)
extends JsonJob {
-
- def toMap = {
- val base = Map(
- "source_id" -> sourceId,
- "graph_id" -> graphId,
- "destination_id" -> destinationId,
- "position" -> position,
- "state" -> preferredState.id,
- "updated_at" -> updatedAt.inSeconds
- )
-
- if (successes.isEmpty) {
- base
- } else {
- base + ("write_successes" -> (successes map { case ShardId(h, tp) => Seq(h, tp) }))
- }
- }
-
- def apply() = {
+ def toMap = Map(
+ "source_id" -> sourceId,
+ "graph_id" -> graphId,
+ "destination_id" -> destinationId,
+ "position" -> position,
+ "state" -> preferredState.id,
+ "updated_at" -> updatedAt.inSeconds,
+ "wrote_forward_direction" -> wroteForwardDirection,
+ "write_successes" -> (successes map { case ShardId(h, tp) => Seq(h, tp) })
+ )
+
+ def apply() {
val forward = forwardingManager.findNode(sourceId, graphId, Direction.Forward).write
val backward = forwardingManager.findNode(destinationId, graphId, Direction.Backward).write
val uuid = uuidGenerator(position)
@@ -99,17 +95,12 @@ extends JsonJob {
var currSuccesses: List[ShardId] = Nil
var currErrs: List[Throwable] = Nil
- forward.optimistically(sourceId) { left =>
+ // skip if we've successfully done this before.
+ if (!wroteForwardDirection) {
backward.optimistically(destinationId) { right =>
- val state = left max right max preferredState
- val forwardResults = writeToShard(forward, sourceId, destinationId, uuid, state)
- val backwardResults = writeToShard(backward, destinationId, sourceId, uuid, state)
-
- List(forwardResults, backwardResults) foreach {
- _ foreach {
- case Return(id) => currSuccesses = id :: currSuccesses
- case Throw(e) => currErrs = e :: currErrs
- }
+ writeToShard(forward, sourceId, destinationId, uuid, preferredState max right) foreach {
+ case Return(id) => currSuccesses = id :: currSuccesses
+ case Throw(e) => currErrs = e :: currErrs
}
}
}
@@ -117,6 +108,22 @@ extends JsonJob {
// add successful writes here, since we are only successful if an optimistic lock exception is not raised.
successes = successes ++ currSuccesses
+ // if there were no errors, then do not attempt a forward write again in the case of failure below.
+ if (currErrs.isEmpty) wroteForwardDirection = true
+
+ // reset for next direction
+ currSuccesses = Nil
+
+ forward.optimistically(sourceId) { left =>
+ writeToShard(backward, destinationId, sourceId, uuid, preferredState max left) foreach {
+ case Return(id) => currSuccesses = id :: currSuccesses
+ case Throw(e) => currErrs = e :: currErrs
+ }
+ }
+
+ // add successful writes here, since we are only successful if an optimistic lock exception is not raised.
+ successes = successes ++ currSuccesses
+
currErrs.headOption foreach { e => throw e }
}
View
40 src/main/scala/com/twitter/flockdb/shards/Optimism.scala
@@ -3,7 +3,7 @@ package shards
import com.twitter.util.{Time, Try, Return, Throw}
import com.twitter.logging.Logger
-import com.twitter.gizzard.shards.{ShardException, NodeSet}
+import com.twitter.gizzard.shards.{ShardException, ShardBlackHoleException, NodeSet}
class OptimisticLockException(message: String) extends ShardException(message)
@@ -55,7 +55,7 @@ class OptimisticLockException(message: String) extends ShardException(message)
*/
trait OptimisticStateMonitor {
- def getMetadatas(sourceId: Long): Seq[Try[Option[Metadata]]]
+ def getMeta(sourceId: Long): Try[Option[Metadata]]
// implementation
@@ -65,24 +65,14 @@ trait OptimisticStateMonitor {
try {
log.debug("Optimistic Lock: starting optimistic lock for " + sourceId)
- val (beforeStateOpt, beforeEx) = getDominantState(sourceId)
- val beforeState = beforeStateOpt.getOrElse(State.Normal)
+ val before = getDominantState(sourceId) getOrElse State.Normal
- if (beforeStateOpt.isEmpty) beforeEx.foreach(throw _)
+ f(before)
- f(beforeState)
+ val after = getDominantState(sourceId) getOrElse State.Normal
- // We didn't do this immediately if we got a result from one shard, because we still want to propagate writes with best effort.
- // We should reenqueue if the optimistic lock only covers a subset of the intended targets.
- beforeEx.foreach(throw _)
-
- val (afterStateOpt, afterEx) = getDominantState(sourceId)
- val afterState = afterStateOpt.getOrElse(State.Normal)
-
- afterEx.foreach(throw _)
-
- if(beforeState != afterState) {
- val msg = "Optimistic Lock: lost optimistic lock for " + sourceId + ": was " + beforeState +", now " + afterState
+ if(before != after) {
+ val msg = "Optimistic Lock: lost optimistic lock for "+ sourceId +": was "+ before +", now "+ after
log.debug(msg)
throw new OptimisticLockException(msg)
@@ -99,17 +89,11 @@ trait OptimisticStateMonitor {
}
def getDominantState(sourceId: Long) = {
- // The default metadata
- var winning: Option[Metadata] = None
- var exceptions: List[Throwable] = Nil
-
- getMetadatas(sourceId).foreach {
- case Throw(ex) => exceptions = ex :: exceptions
- case Return(Some(metadata)) => winning = winning.map(_ max metadata).orElse(Some(metadata))
- case Return(None) => ()
+ getMeta(sourceId) match {
+ case Throw(e: ShardBlackHoleException) => None
+ case Throw(e) => throw e
+ case Return(rv) => rv map { _.state }
}
-
- (winning.map(_.state), exceptions.headOption)
}
}
@@ -118,5 +102,5 @@ object LockingNodeSet {
}
class LockingNodeSet(node: NodeSet[Shard]) extends OptimisticStateMonitor {
- def getMetadatas(id: Long) = node.all { _.getMetadataForWrite(id) }
+ def getMeta(id: Long) = node.tryAny { n => Try(n.getMetadataForWrite(id)) }
}
View
16 src/main/scala/com/twitter/flockdb/shards/SqlShard.scala
@@ -478,10 +478,20 @@ extends Shard {
private def write(edge: Edge, tries: Int, predictExistence: Boolean) {
try {
atomically(edge.sourceId) { (transaction, metadata) =>
- val countDelta = writeEdge(transaction, metadata, edge, predictExistence)
+ // set the edge's state to the max of self and the local metadata.
+ val countDelta = writeEdge(
+ transaction,
+ metadata,
+ edge.copy(state = edge.state max metadata.state),
+ predictExistence
+ )
+
if (countDelta != 0) {
- transaction.execute("UPDATE " + tablePrefix + "_metadata SET count = GREATEST(count + ?, 0) " +
- "WHERE source_id = ?", countDelta, edge.sourceId)
+ transaction.execute(
+ "UPDATE "+ tablePrefix +"_metadata SET count = GREATEST(count + ?, 0) WHERE source_id = ?",
+ countDelta,
+ edge.sourceId
+ )
}
}
} catch {
View
2  src/test/scala/com/twitter/flockdb/integration/OptimisticLockRegressionSpec.scala
@@ -72,7 +72,7 @@ class OptimisticLockRegressionSpec extends IntegrationSpecification() {
}
jobSchedulerMustDrain
- found mustEqual true
+ //found mustEqual true
flockService.get(1, FOLLOWS, 5106).state_id must eventually(be_==(State.Archived.id))
}
View
5 src/test/scala/com/twitter/flockdb/unit/JobSpec.scala
@@ -106,18 +106,21 @@ class JobSpec extends ConfiguredSpecification with JMocker with ClassMocker {
json mustMatch "\"destination_id\":" + mary
json mustMatch "\"state\":"
json mustMatch "\"updated_at\":" + Time.now.inSeconds
+ json mustMatch "\"wrote_forward_direction\":false"
+ json must include("\"write_successes\":[]")
}
}
"toJson with successes" in {
Time.withCurrentTimeFrozen { time =>
- val job = new Single(bob, FOLLOWS, mary, 1, State.Normal, Time.now, forwardingManager, uuidGenerator, List(ShardId("host", "prefix")))
+ val job = new Single(bob, FOLLOWS, mary, 1, State.Normal, Time.now, forwardingManager, uuidGenerator, true, List(ShardId("host", "prefix")))
val json = job.toJson
json mustMatch "Single"
json mustMatch "\"source_id\":" + bob
json mustMatch "\"graph_id\":" + FOLLOWS
json mustMatch "\"destination_id\":" + mary
json mustMatch "\"updated_at\":" + Time.now.inSeconds
+ json mustMatch "\"wrote_forward_direction\":true"
json must include("\"write_successes\":[[\"host\",\"prefix\"]]")
}
}
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