+per #15424 Added PersistentView, deprecated View
A PersistentView works the same way as View did previously, except: * it requires an `peristenceId` (no default is provided) * messages given to `receive` are NOT wrapped in Persistent() akka-streams not touched, will update them afterwards on different branch Also solves #15436 by making persistentId in PersistentView abstract. (cherry picked from commit dcafaf788236fe6d018388dd55d5bf9650ded696) Conflicts: akka-docs/rst/java/lambda-persistence.rst akka-docs/rst/java/persistence.rst akka-docs/rst/scala/persistence.rst akka-persistence/src/main/scala/akka/persistence/Persistent.scala akka-persistence/src/main/scala/akka/persistence/View.scala
This commit is contained in:
Konrad 'ktoso' Malawski
Patrik Nordwall
parent
2203968adb
commit
3fd240384c
22 changed files with 847 additions and 192 deletions
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@ -485,18 +485,21 @@ public class PersistenceDocTest {
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static Object o11 = new Object() {
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//#view
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class MyView extends UntypedView {
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@Override
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public String persistenceId() {
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return "some-persistence-id";
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}
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class MyView extends UntypedPersistentView {
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@Override public String viewId() { return "some-persistence-id-view"; }
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@Override public String persistenceId() { return "some-persistence-id"; }
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@Override
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public void onReceive(Object message) throws Exception {
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if (message instanceof Persistent) {
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// ...
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if (isPersistent()) {
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// handle message from Journal...
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} else if (message instanceof String) {
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// handle message from user...
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} else {
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unhandled(message);
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}
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}
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}
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//#view
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@ -26,6 +26,17 @@ Akka persistence is inspired by the `eventsourced`_ library. It follows the same
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.. _eventsourced: https://github.com/eligosource/eventsourced
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Changes in Akka 2.3.4
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=====================
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In Akka 2.3.4 several of the concepts of the earlier versions were collapsed and simplified.
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In essence; ``Processor`` and ``EventsourcedProcessor`` are replaced by ``PersistentActor``. ``Channel``
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and ``PersistentChannel`` are replaced by ``AtLeastOnceDelivery``. ``View`` is replaced by ``PersistentView``.
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See full details of the changes in the :ref:`migration-guide-persistence-experimental-2.3.x-2.4.x`.
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The old classes are still included, and deprecated, for a while to make the transition smooth.
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In case you need the old documentation it is located `here <http://doc.akka.io/docs/akka/2.3.3/java/lambda-persistence.html#persistence-lambda-java>`_.
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Dependencies
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============
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@ -45,7 +56,7 @@ Architecture
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When a persistent actor is started or restarted, journaled messages are replayed to that actor, so that it can
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recover internal state from these messages.
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* *View*: A view is a persistent, stateful actor that receives journaled messages that have been written by another
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* *AbstractPersistentView*: A view is a persistent, stateful actor that receives journaled messages that have been written by another
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persistent actor. A view itself does not journal new messages, instead, it updates internal state only from a persistent actor's
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replicated message stream.
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@ -260,12 +271,12 @@ to Akka persistence will allow to replay messages that have been marked as delet
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purposes, for example. To delete all messages (journaled by a single persistent actor) up to a specified sequence number,
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persistent actors should call the ``deleteMessages`` method.
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.. _views-java-lambda:
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.. _persistent-views-java-lambda:
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Views
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=====
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Views can be implemented by extending the ``AbstractView`` abstract class, implement the ``persistenceId`` method
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Persistent views can be implemented by extending the ``AbstractView`` abstract class, implement the ``persistenceId`` method
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and setting the “initial behavior” in the constructor by calling the :meth:`receive` method.
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.. includecode:: ../../../akka-samples/akka-sample-persistence-java-lambda/src/main/java/doc/LambdaPersistenceDocTest.java#view
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@ -275,14 +286,18 @@ the referenced persistent actor is actually running. Views read messages from a
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persistent actor is started later and begins to write new messages, the corresponding view is updated automatically, by
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default.
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It is possible to determine if a message was sent from the Journal or from another actor in user-land by calling the ``isPersistent``
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method. Having that said, very often you don't need this information at all and can simply apply the same logic to both cases
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(skip the ``if isPersistent`` check).
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Updates
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-------
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The default update interval of all views of an actor system is configurable:
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The default update interval of all persistent views of an actor system is configurable:
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.. includecode:: ../scala/code/docs/persistence/PersistenceDocSpec.scala#auto-update-interval
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``View`` implementation classes may also override the ``autoUpdateInterval`` method to return a custom update
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``AbstractPersistentView`` implementation classes may also override the ``autoUpdateInterval`` method to return a custom update
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interval for a specific view class or view instance. Applications may also trigger additional updates at
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any time by sending a view an ``Update`` message.
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@ -293,7 +308,7 @@ incremental message replay, triggered by that update request, completed. If set
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following the update request may interleave with the replayed message stream. Automated updates always run with
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``await = false``.
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Automated updates of all views of an actor system can be turned off by configuration:
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Automated updates of all persistent views of an actor system can be turned off by configuration:
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.. includecode:: ../scala/code/docs/persistence/PersistenceDocSpec.scala#auto-update
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@ -305,20 +320,20 @@ of replayed messages for manual updates can be limited with the ``replayMax`` pa
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Recovery
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--------
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Initial recovery of views works in the very same way as for a persistent actor (i.e. by sending a ``Recover`` message
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Initial recovery of persistent views works in the very same way as for a persistent actor (i.e. by sending a ``Recover`` message
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to self). The maximum number of replayed messages during initial recovery is determined by ``autoUpdateReplayMax``.
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Further possibilities to customize initial recovery are explained in section :ref:`recovery-java-lambda`.
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Further possibilities to customize initial recovery are explained in section :ref:`recovery-java`.
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.. _persistence-identifiers-java-lambda:
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Identifiers
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-----------
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A view must have an identifier that doesn't change across different actor incarnations. It defaults to the
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A persistent view must have an identifier that doesn't change across different actor incarnations. It defaults to the
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``String`` representation of the actor path without the address part and can be obtained via the ``viewId``
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method.
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Applications can customize a view's id by specifying an actor name during view creation. This changes that view's
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Applications can customize a view's id by specifying an actor name during view creation. This changes that persistent view's
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name in its actor hierarchy and hence influences only part of the view id. To fully customize a view's id, the
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``viewId`` method must be overridden. Overriding ``viewId`` is the recommended way to generate stable identifiers.
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@ -338,7 +353,7 @@ Snapshots
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=========
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Snapshots can dramatically reduce recovery times of persistent actors and views. The following discusses snapshots
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in context of persistent actors but this is also applicable to views.
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in context of persistent actors but this is also applicable to persistent views.
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Persistent actor can save snapshots of internal state by calling the ``saveSnapshot`` method. If saving of a snapshot
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succeeds, the persistent actor receives a ``SaveSnapshotSuccess`` message, otherwise a ``SaveSnapshotFailure`` message
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@ -31,6 +31,17 @@ concepts and architecture of `eventsourced`_ but significantly differs on API an
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.. _eventsourced: https://github.com/eligosource/eventsourced
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Changes in Akka 2.3.4
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=====================
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In Akka 2.3.4 several of the concepts of the earlier versions were collapsed and simplified.
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In essence; ``Processor`` and ``EventsourcedProcessor`` are replaced by ``PersistentActor``. ``Channel``
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and ``PersistentChannel`` are replaced by ``AtLeastOnceDelivery``. ``View`` is replaced by ``PersistentView``.
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See full details of the changes in the :ref:`migration-guide-persistence-experimental-2.3.x-2.4.x`.
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The old classes are still included, and deprecated, for a while to make the transition smooth.
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In case you need the old documentation it is located `here <http://doc.akka.io/docs/akka/2.3.3/java/persistence.html>`_.
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Dependencies
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============
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@ -50,7 +61,7 @@ Architecture
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When a persistent actor is started or restarted, journaled messages are replayed to that actor, so that it can
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recover internal state from these messages.
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* *View*: A view is a persistent, stateful actor that receives journaled messages that have been written by another
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* *UntypedPersistentView*: A view is a persistent, stateful actor that receives journaled messages that have been written by another
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persistent actor. A view itself does not journal new messages, instead, it updates internal state only from a persistent actor's
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replicated message stream.
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@ -265,13 +276,13 @@ to Akka persistence will allow to replay messages that have been marked as delet
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purposes, for example. To delete all messages (journaled by a single persistent actor) up to a specified sequence number,
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persistent actors should call the ``deleteMessages`` method.
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.. _views-java:
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.. _persistent-views-java:
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Views
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=====
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Persistent Views
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================
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Views can be implemented by extending the ``UntypedView`` trait and implementing the ``onReceive`` and the ``persistenceId``
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methods.
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Persistent views can be implemented by extending the ``UntypedPersistentView`` trait and implementing the ``onReceive``
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and the ``persistenceId`` methods.
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.. includecode:: code/docs/persistence/PersistenceDocTest.java#view
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@ -280,14 +291,18 @@ the referenced persistent actor is actually running. Views read messages from a
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persistent actor is started later and begins to write new messages, the corresponding view is updated automatically, by
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default.
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It is possible to determine if a message was sent from the Journal or from another actor in user-land by calling the ``isPersistent``
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method. Having that said, very often you don't need this information at all and can simply apply the same logic to both cases
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(skip the ``if isPersistent`` check).
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Updates
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-------
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The default update interval of all views of an actor system is configurable:
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The default update interval of all persistent views of an actor system is configurable:
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.. includecode:: ../scala/code/docs/persistence/PersistenceDocSpec.scala#auto-update-interval
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``View`` implementation classes may also override the ``autoUpdateInterval`` method to return a custom update
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``UntypedPersistentView`` implementation classes may also override the ``autoUpdateInterval`` method to return a custom update
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interval for a specific view class or view instance. Applications may also trigger additional updates at
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any time by sending a view an ``Update`` message.
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@ -298,7 +313,7 @@ incremental message replay, triggered by that update request, completed. If set
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following the update request may interleave with the replayed message stream. Automated updates always run with
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``await = false``.
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Automated updates of all views of an actor system can be turned off by configuration:
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Automated updates of all persistent views of an actor system can be turned off by configuration:
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.. includecode:: ../scala/code/docs/persistence/PersistenceDocSpec.scala#auto-update
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@ -310,7 +325,7 @@ of replayed messages for manual updates can be limited with the ``replayMax`` pa
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Recovery
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--------
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Initial recovery of views works in the very same way as for a persistent actor (i.e. by sending a ``Recover`` message
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Initial recovery of persistent views works in the very same way as for a persistent actor (i.e. by sending a ``Recover`` message
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to self). The maximum number of replayed messages during initial recovery is determined by ``autoUpdateReplayMax``.
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Further possibilities to customize initial recovery are explained in section :ref:`recovery-java`.
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@ -319,11 +334,11 @@ Further possibilities to customize initial recovery are explained in section :re
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Identifiers
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-----------
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A view must have an identifier that doesn't change across different actor incarnations. It defaults to the
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A persistent view must have an identifier that doesn't change across different actor incarnations. It defaults to the
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``String`` representation of the actor path without the address part and can be obtained via the ``viewId``
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method.
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Applications can customize a view's id by specifying an actor name during view creation. This changes that view's
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Applications can customize a view's id by specifying an actor name during view creation. This changes that persistent view's
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name in its actor hierarchy and hence influences only part of the view id. To fully customize a view's id, the
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``viewId`` method must be overridden. Overriding ``viewId`` is the recommended way to generate stable identifiers.
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@ -343,7 +358,7 @@ Snapshots
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=========
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Snapshots can dramatically reduce recovery times of persistent actor and views. The following discusses snapshots
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in context of persistent actor but this is also applicable to views.
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in context of persistent actor but this is also applicable to persistent views.
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Persistent actor can save snapshots of internal state by calling the ``saveSnapshot`` method. If saving of a snapshot
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succeeds, the persistent actor receives a ``SaveSnapshotSuccess`` message, otherwise a ``SaveSnapshotFailure`` message
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