Github user dhruve commented on a diff in the pull request:
https://github.com/apache/spark/pull/18487#discussion_r128557269
--- Diff:
core/src/main/scala/org/apache/spark/storage/ShuffleBlockFetcherIterator.scala
---
@@ -443,12 +459,57 @@ final class ShuffleBlockFetcherIterator(
}
private def fetchUpToMaxBytes(): Unit = {
- // Send fetch requests up to maxBytesInFlight
- while (fetchRequests.nonEmpty &&
- (bytesInFlight == 0 ||
- (reqsInFlight + 1 <= maxReqsInFlight &&
- bytesInFlight + fetchRequests.front.size <= maxBytesInFlight))) {
- sendRequest(fetchRequests.dequeue())
+ // Send fetch requests up to maxBytesInFlight. If you cannot fetch
from a remote host
+ // immediately, defer the request until the next time it can be
processed.
+
+ // Process any outstanding deferred fetch requests if possible.
+ if (deferredFetchRequests.nonEmpty) {
+ for ((remoteAddress, defReqQueue) <- deferredFetchRequests) {
+ while (isRemoteBlockFetchable(defReqQueue) &&
+ !isRemoteAddressMaxedOut(remoteAddress, defReqQueue.front)) {
+ val request = defReqQueue.dequeue()
+ logDebug(s"Processing deferred fetch request for $remoteAddress
with "
+ + s"${request.blocks.length} blocks")
+ send(remoteAddress, request)
+ if (defReqQueue.isEmpty) {
+ deferredFetchRequests -= remoteAddress
--- End diff --
We would have to unnecessarily iterate through the map for all the block
manager ids for which we deferred fetch requests at an earlier point to check
if they have any pending fetch requests when they don't.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
