X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=akka%2Frepackaged-akka-jar%2Fsrc%2Fmain%2Fresources%2Fstream_reference.conf;h=66d9130e38a46a893496965a37531334be0f3c2b;hp=a29e83a9f7527fc1af5d5c353f146a995c965521;hb=e2c835865f5c6534758d2bfd0451efef1545a98f;hpb=c355a5b632433b9d2a54107d24e644e68610f270

diff --git a/akka/repackaged-akka-jar/src/main/resources/stream_reference.conf b/akka/repackaged-akka-jar/src/main/resources/stream_reference.conf
index a29e83a9f7..66d9130e38 100644
--- a/akka/repackaged-akka-jar/src/main/resources/stream_reference.conf
+++ b/akka/repackaged-akka-jar/src/main/resources/stream_reference.conf
@@ -2,6 +2,8 @@
 # Akka Stream Reference Config File #
 #####################################
 
+# eager creation of the system wide materializer
+akka.library-extensions += "akka.stream.SystemMaterializer$"
 akka {
   stream {
 
@@ -14,11 +16,13 @@ akka {
       max-input-buffer-size = 16
 
       # Fully qualified config path which holds the dispatcher configuration
-      # to be used by ActorMaterializer when creating Actors.
-      # When this value is left empty, the default-dispatcher will be used.
-      dispatcher = ""
+      # or full dispatcher configuration to be used by ActorMaterializer when creating Actors.
+      dispatcher = "akka.actor.default-dispatcher"
 
-      blocking-io-dispatcher = "akka.stream.default-blocking-io-dispatcher"
+      # Fully qualified config path which holds the dispatcher configuration
+      # or full dispatcher configuration to be used by stream operators that
+      # perform blocking operations
+      blocking-io-dispatcher = "akka.actor.default-blocking-io-dispatcher"
 
       # Cleanup leaked publishers and subscribers when they are not used within a given
       # deadline
@@ -76,15 +80,51 @@ akka {
       }
 
       io.tcp {
-        # The outgoing bytes are accumulated in a buffer while waiting for acknoledgment
+        # The outgoing bytes are accumulated in a buffer while waiting for acknowledgment
         # of pending write. This improves throughput for small messages (frames) without
         # sacrificing latency. While waiting for the ack the stage will eagerly pull
         # from upstream until the buffer exceeds this size. That means that the buffer may hold
         # slightly more bytes than this limit (at most one element more). It can be set to 0
         # to disable the usage of the buffer.
         write-buffer-size = 16 KiB
+
+        # In addition to the buffering described for property write-buffer-size, try to collect
+        # more consecutive writes from the upstream stream producers.
+        #
+        # The rationale is to increase write efficiency by avoiding separate small
+        # writes to the network which is expensive to do. Merging those writes together
+        # (up to `write-buffer-size`) improves throughput for small writes.
+        #
+        # The idea is that a running stream may produce multiple small writes consecutively
+        # in one go without waiting for any external input. To probe the stream for
+        # data, this features delays sending a write immediately by probing the stream
+        # for more writes. This works by rescheduling the TCP connection stage via the
+        # actor mailbox of the underlying actor. Thus, before the stage is reactivated
+        # the upstream gets another opportunity to emit writes.
+        #
+        # When the stage is reactivated and if new writes are detected another round-trip
+        # is scheduled. The loop repeats until either the number of round trips given in this
+        # setting is reached, the buffer reaches `write-buffer-size`, or no new writes
+        # were detected during the last round-trip.
+        #
+        # This mechanism ensures that a write is guaranteed to be sent when the remaining stream
+        # becomes idle waiting for external signals.
+        #
+        # In most cases, the extra latency this mechanism introduces should be negligible,
+        # but depending on the stream setup it may introduce a noticeable delay,
+        # if the upstream continuously produces small amounts of writes in a
+        # blocking (CPU-bound) way.
+        #
+        # In that case, the feature can either be disabled, or the producing CPU-bound
+        # work can be taken off-stream to avoid excessive delays (e.g. using `mapAsync` instead of `map`).
+        #
+        # A value of 0 disables this feature.
+        coalesce-writes = 10
       }
 
+      # Time to wait for async materializer creation before throwing an exception
+      creation-timeout = 20 seconds
+
       //#stream-ref
       # configure defaults for SourceRef and SinkRef
       stream-ref {
@@ -122,21 +162,12 @@ akka {
       //#stream-ref
     }
 
-    # Deprecated, use akka.stream.materializer.blocking-io-dispatcher, this setting
-    # was never applied because of bug #24357
-    # It must still have a valid value because used from Akka HTTP.
-    blocking-io-dispatcher = "akka.stream.default-blocking-io-dispatcher"
-
-    default-blocking-io-dispatcher {
-      type = "Dispatcher"
-      executor = "thread-pool-executor"
-      throughput = 1
-
-      thread-pool-executor {
-        fixed-pool-size = 16
-      }
-    }
+    # Deprecated, left here to not break Akka HTTP which refers to it
+    blocking-io-dispatcher = "akka.actor.default-blocking-io-dispatcher"
 
+    # Deprecated, will not be used unless user code refer to it, use 'akka.stream.materializer.blocking-io-dispatcher'
+    # instead, or if from code, prefer the 'ActorAttributes.IODispatcher' attribute
+    default-blocking-io-dispatcher = "akka.actor.default-blocking-io-dispatcher"
   }
 
   # configure overrides to ssl-configuration here (to be used by akka-streams, and akka-http – i.e. when serving https connections)