1 #####################################
2 # Akka Stream Reference Config File #
3 #####################################
8 # Default materializer settings
11 # Initial size of buffers used in stream elements
12 initial-input-buffer-size = 4
13 # Maximum size of buffers used in stream elements
14 max-input-buffer-size = 16
16 # Fully qualified config path which holds the dispatcher configuration
17 # to be used by ActorMaterializer when creating Actors.
18 # When this value is left empty, the default-dispatcher will be used.
21 blocking-io-dispatcher = "akka.stream.default-blocking-io-dispatcher"
23 # Cleanup leaked publishers and subscribers when they are not used within a given
25 subscription-timeout {
26 # when the subscription timeout is reached one of the following strategies on
27 # the "stale" publisher:
28 # cancel - cancel it (via `onError` or subscribing to the publisher and
29 # `cancel()`ing the subscription right away
30 # warn - log a warning statement about the stale element (then drop the
32 # noop - do nothing (not recommended)
35 # time after which a subscriber / publisher is considered stale and eligible
36 # for cancelation (see `akka.stream.subscription-timeout.mode`)
40 # Enable additional troubleshooting logging at DEBUG log level
43 # Maximum number of elements emitted in batch if downstream signals large demand
44 output-burst-limit = 1000
46 # Enable automatic fusing of all graphs that are run. For short-lived streams
47 # this may cause an initial runtime overhead, but most of the time fusing is
48 # desirable since it reduces the number of Actors that are created.
49 # Deprecated, since Akka 2.5.0, setting does not have any effect.
52 # Those stream elements which have explicit buffers (like mapAsync, mapAsyncUnordered,
53 # buffer, flatMapMerge, Source.actorRef, Source.queue, etc.) will preallocate a fixed
54 # buffer upon stream materialization if the requested buffer size is less than this
55 # configuration parameter. The default is very high because failing early is better
56 # than failing under load.
58 # Buffers sized larger than this will dynamically grow/shrink and consume more memory
59 # per element than the fixed size buffers.
60 max-fixed-buffer-size = 1000000000
62 # Maximum number of sync messages that actor can process for stream to substream communication.
63 # Parameter allows to interrupt synchronous processing to get upstream/downstream messages.
64 # Allows to accelerate message processing that happening within same actor but keep system responsive.
65 sync-processing-limit = 1000
68 # Enables the fuzzing mode which increases the chance of race conditions
69 # by aggressively reordering events and making certain operations more
70 # concurrent than usual.
71 # This setting is for testing purposes, NEVER enable this in a production
73 # To get the best results, try combining this setting with a throughput
74 # of 1 on the corresponding dispatchers.
79 # The outgoing bytes are accumulated in a buffer while waiting for acknoledgment
80 # of pending write. This improves throughput for small messages (frames) without
81 # sacrificing latency. While waiting for the ack the stage will eagerly pull
82 # from upstream until the buffer exceeds this size. That means that the buffer may hold
83 # slightly more bytes than this limit (at most one element more). It can be set to 0
84 # to disable the usage of the buffer.
85 write-buffer-size = 16 KiB
89 # configure defaults for SourceRef and SinkRef
91 # Buffer of a SinkRef that is used to batch Request elements from the other side of the stream ref
93 # The buffer will be attempted to be filled eagerly even while the local stage did not request elements,
94 # because the delay of requesting over network boundaries is much higher.
97 # Demand is signalled by sending a cumulative demand message ("requesting messages until the n-th sequence number)
98 # Using a cumulative demand model allows us to re-deliver the demand message in case of message loss (which should
99 # be very rare in any case, yet possible -- mostly under connection break-down and re-establishment).
101 # The semantics of handling and updating the demand however are in-line with what Reactive Streams dictates.
103 # In normal operation, demand is signalled in response to arriving elements, however if no new elements arrive
104 # within `demand-redelivery-interval` a re-delivery of the demand will be triggered, assuming that it may have gotten lost.
105 demand-redelivery-interval = 1 second
107 # Subscription timeout, during which the "remote side" MUST subscribe (materialize) the handed out stream ref.
108 # This timeout does not have to be very low in normal situations, since the remote side may also need to
109 # prepare things before it is ready to materialize the reference. However the timeout is needed to avoid leaking
110 # in-active streams which are never subscribed to.
111 subscription-timeout = 30 seconds
113 # In order to guard the receiving end of a stream ref from never terminating (since awaiting a Completion or Failed
114 # message) after / before a Terminated is seen, a special timeout is applied once Terminated is received by it.
115 # This allows us to terminate stream refs that have been targeted to other nodes which are Downed, and as such the
116 # other side of the stream ref would never send the "final" terminal message.
118 # The timeout specifically means the time between the Terminated signal being received and when the local SourceRef
119 # determines to fail itself, assuming there was message loss or a complete partition of the completion signal.
120 final-termination-signal-deadline = 2 seconds
125 # Deprecated, use akka.stream.materializer.blocking-io-dispatcher, this setting
126 # was never applied because of bug #24357
127 # It must still have a valid value because used from Akka HTTP.
128 blocking-io-dispatcher = "akka.stream.default-blocking-io-dispatcher"
130 default-blocking-io-dispatcher {
132 executor = "thread-pool-executor"
135 thread-pool-executor {
142 # configure overrides to ssl-configuration here (to be used by akka-streams, and akka-http – i.e. when serving https connections)
150 akka-stream-ref = "akka.stream.serialization.StreamRefSerializer"
153 serialization-bindings {
154 "akka.stream.SinkRef" = akka-stream-ref
155 "akka.stream.SourceRef" = akka-stream-ref
156 "akka.stream.impl.streamref.StreamRefsProtocol" = akka-stream-ref
159 serialization-identifiers {
160 "akka.stream.serialization.StreamRefSerializer" = 30
166 # folded in from former ssl-config-akka module
168 logger = "com.typesafe.sslconfig.akka.util.AkkaLoggerBridge"