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Decrease waiting-for-state-timeout to 2s (#27025)

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* Decrease waiting-for-state-timeout to 2s

The timeout can be likely to happen for small clusters when the read
majority needs to go to every node

Refs #26710

* Restructure migration guide for 2.6

Separate out changes that require no user action unless the old
behavior is preferred

* Update akka-docs/src/main/paradox/project/migration-guide-2.5.x-2.6.x.md

Co-Authored-By: Arnout Engelen <github@bzzt.net>
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Christopher Batey 2019-06-06 10:22:26 +01:00 • committed by GitHub
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7
akka-cluster-sharding/src/main/resources/reference.conf
View file

@ -108,9 +108,12 @@ akka.cluster.sharding {
max-simultaneous-rebalance = 3
}
# Timeout of waiting the initial distributed state (an initial state will be queried again if the timeout happened)
# Timeout of waiting the initial distributed state for the shard coordinator (an initial state will be queried again if the timeout happened)
# and for a shard to get its state when remembered entities is enabled
# The read from ddata is a ReadMajority, for small clusters (< majority-min-cap) every node needs to respond
# so is more likely to time out if there are nodes restarting e.g. when there is a rolling re-deploy happening
# Only used when state-store-mode=ddata
waiting-for-state-timeout = 5 s
waiting-for-state-timeout = 2 s
# Timeout of waiting for update the distributed state (update will be retried if the timeout happened)
# Only used when state-store-mode=ddata

98
akka-docs/src/main/paradox/project/migration-guide-2.5.x-2.6.x.md
View file

@ -45,6 +45,12 @@ Use plain `system.actorOf` instead of the DSL to create Actors if you have been
`actorFor` has been deprecated since `2.2`. Use `ActorSelection` instead.
### Netty UDP removed
Classic remoting over UDP has been deprecated since `2.5.0` and now has been removed.
To continue to use UDP configure @ref[Artery UDP](../remoting-artery.md#configuring-ssl-tls-for-akka-remoting) or migrate to Artery TCP.
A full cluster restart is required to change to Artery.
### Untyped actor removed
`UntypedActor` has been depcated since `2.5.0`. Use `AbstractActor` instead.
@ -98,33 +104,6 @@ to make remote interactions look like local method calls.
Warnings about `TypedActor` have been [mentioned in documentation](https://doc.akka.io/docs/akka/2.5/typed-actors.html#when-to-use-typed-actors)
for many years.
## Internal dispatcher introduced
To protect the Akka internals against starvation when user code blocks the default dispatcher (for example by accidental
use of blocking APIs from actors) a new internal dispatcher has been added. All of Akka's internal, non-blocking actors
now run on the internal dispatcher by default.
The dispatcher can be configured through `akka.actor.internal-dispatcher`.
For maximum performance, you might want to use a single shared dispatcher for all non-blocking,
asynchronous actors, user actors and Akka internal actors. In that case, can configure the
`akka.actor.internal-dispatcher` with a string value of `akka.actor.default-dispatcher`.
This reinstantiates the behavior from previous Akka versions but also removes the isolation between
user and Akka internals. So, use at your own risk!
Several `use-dispatcher` configuration settings that previously accepted an empty value to fall back to the default
dispatcher has now gotten an explicit value of `akka.actor.internal-dispatcher` and no longer accept an empty
string as value. If such an empty value is used in your `application.conf` the same result is achieved by simply removing
that entry completely and having the default apply.
For more details about configuring dispatchers, see the @ref[Dispatchers](../dispatchers.md)
## Default dispatcher size
Previously the factor for the default dispatcher was set a bit high (`3.0`) to give some extra threads in case of accidental
blocking and protect a bit against starving the internal actors. Since the internal actors are now on a separate dispatcher
the default dispatcher has been adjusted down to `1.0` which means the number of threads will be one per core, but at least
`8` and at most `64`. This can be tuned using the individual settings in `akka.actor.default-dispatcher.fork-join-executor`.
@@ Remoting
@ -133,10 +112,6 @@ the default dispatcher has been adjusted down to `1.0` which means the number of
@ref[Artery TCP](../remoting-artery.md) is now the default remoting implementation.
Classic remoting has been deprecated and will be removed in `2.7.0`.
## Akka now uses Fork Join Pool from JDK
Previously, Akka contained a shaded copy of the ForkJoinPool. In benchmarks, we could not find significant benefits of
keeping our own copy, so from Akka 2.6 on, the default FJP from the JDK will be used. The Akka FJP copy was removed.
<a id="classic-to-artery"></a>
#### Migrating from classic remoting to Artery
@ -200,11 +175,11 @@ Classic remoting is deprecated but can be used in `2.6.` Any configuration under
specific to classic remoting needs to be moved to `akka.remote.classic`. To see which configuration options
are specific to classic search for them in: [`akka-remote/reference.conf`](/akka-remote/src/main/resources/reference.conf)
### Netty UDP has been removed
Classic remoting over UDP has been deprecated since `2.5.0` and now has been removed.
To continue to use UDP configure @ref[Artery UDP](../remoting-artery.md#configuring-ssl-tls-for-akka-remoting) or migrate to Artery TCP.
A full cluster restart is required to change to Artery.
## Configuration and behavior changes
The following documents configuration changes and behavior changes where no action is required. In some cases the old
behavior can be restored via configuration.
### Remoting dependencies have been made optional
@ -230,16 +205,44 @@ For the same reason the following methods have also been deprecated:
* `FSM.setTimer`, replaced by `startSingleTimer`, `startTimerWithFixedDelay` or `startTimerAtFixedRate`
* `PersistentFSM.setTimer`, replaced by `startSingleTimer`, `startTimerWithFixedDelay` or `startTimerAtFixedRate`
## Streams
### Internal dispatcher introduced
### StreamRefs
To protect the Akka internals against starvation when user code blocks the default dispatcher (for example by accidental
use of blocking APIs from actors) a new internal dispatcher has been added. All of Akka's internal, non-blocking actors
now run on the internal dispatcher by default.
The materialized value for `StreamRefs.sinkRef` and `StreamRefs.sourceRef` is no longer wrapped in
`Future`/`CompletionStage`. It can be sent as reply to `sender()` immediately without using the `pipe` pattern.
The dispatcher can be configured through `akka.actor.internal-dispatcher`.
## Cluster Sharding
For maximum performance, you might want to use a single shared dispatcher for all non-blocking,
asynchronous actors, user actors and Akka internal actors. In that case, can configure the
`akka.actor.internal-dispatcher` with a string value of `akka.actor.default-dispatcher`.
This reinstantiates the behavior from previous Akka versions but also removes the isolation between
user and Akka internals. So, use at your own risk!
Several `use-dispatcher` configuration settings that previously accepted an empty value to fall back to the default
dispatcher has now gotten an explicit value of `akka.actor.internal-dispatcher` and no longer accept an empty
string as value. If such an empty value is used in your `application.conf` the same result is achieved by simply removing
that entry completely and having the default apply.
For more details about configuring dispatchers, see the @ref[Dispatchers](../dispatchers.md)
### Default dispatcher size
Previously the factor for the default dispatcher was set a bit high (`3.0`) to give some extra threads in case of accidental
blocking and protect a bit against starving the internal actors. Since the internal actors are now on a separate dispatcher
the default dispatcher has been adjusted down to `1.0` which means the number of threads will be one per core, but at least
`8` and at most `64`. This can be tuned using the individual settings in `akka.actor.default-dispatcher.fork-join-executor`.
### Cluster sharding
#### waiting-for-state-timeout reduced to 2s
This has been reduced to speed up ShardCoordinator initialization in smaller clusters.
The read from ddata is a ReadMajority, for small clusters (< majority-min-cap) every node needs to respond
so is more likely to timeout if there are nodes restarting e.g. when there is a rolling re-deploy happening.
### Passivate idle entity
The configuration `akka.cluster.sharding.passivate-idle-entity-after` is now enabled by default.
Sharding will passivate entities when they have not received any messages after this duration.
To disable passivation you can use configuration:
@ -248,7 +251,7 @@ To disable passivation you can use configuration:
akka.cluster.sharding.passivate-idle-entity-after = off
```
## CoordinatedShutdown is run from ActorSystem.terminate
### CoordinatedShutdown is run from ActorSystem.terminate
No migration is needed but it is mentioned here because it is a change in behavior.
@ -263,6 +266,19 @@ and then it will behave as in Akka 2.5.x:
akka.coordinated-shutdown.run-by-actor-system-terminate = off
```
### Akka now uses Fork Join Pool from JDK
Previously, Akka contained a shaded copy of the ForkJoinPool. In benchmarks, we could not find significant benefits of
keeping our own copy, so from Akka 2.6 on, the default FJP from the JDK will be used. The Akka FJP copy was removed.
## Source incompatibilities
### StreamRefs
The materialized value for `StreamRefs.sinkRef` and `StreamRefs.sourceRef` is no longer wrapped in
`Future`/`CompletionStage`. It can be sent as reply to `sender()` immediately without using the `pipe` pattern.
## Akka Typed
### Receptionist has moved