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Christopher Batey 2020-08-24 11:29:56 +01:00
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akka-docs/src/main/paradox/project/examples.md
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@ -61,7 +61,7 @@ from the events, or publish the events to other services.
## Multi-DC Persistence
This commercial feature has now been superseeded by @ref[Replicated Event Sourcing](../typed/replicated-eventsourcing.md)
This commercial feature has now been superseded by @ref[Replicated Event Sourcing](../typed/replicated-eventsourcing.md)
## Cluster with Docker

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akka-docs/src/main/paradox/typed/cluster-dc.md
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@ -193,7 +193,7 @@ Especially when used together with Akka Persistence that is based on the single-
it is important to avoid running the same entity at multiple locations at the same time with a
shared data store. That would result in corrupt data since the events stored by different instances
may be interleaved and would be interpreted differently in a later replay. For replicated persistent
entities see @ref[Replciated Event Sourcing](replicated-eventsourcing.md).
entities see @ref[Replicated Event Sourcing](replicated-eventsourcing.md).
If you need global entities you have to pick one data center to host that entity type and only start
`ClusterSharding` on nodes of that data center. If the data center is unreachable from another data center the

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akka-docs/src/main/paradox/typed/replicated-eventsourcing-auction.md
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@ -25,7 +25,7 @@ Scala
Java
: @@snip [AuctionExample](/akka-persistence-typed-tests/src/test/java/jdocs/akka/persistence/typed/ReplicatedAuctionExampleTest.java) { #events }
The winner does not have to pay the highest bid but only enough to beat the second highest so the `highestCounterOffer` is in the `AuctionFinished` event.
The winner does not have to pay the highest bid but only enough to beat the second highest, so the `highestCounterOffer` is in the `AuctionFinished` event.
Let's have a look at the auction entity that will handle incoming commands:

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akka-docs/src/main/paradox/typed/replicated-eventsourcing.md
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@ -8,7 +8,8 @@ warning or deprecation period. It is also not recommended to use this module in
@@@
@ref[Event sourcing](./persistence.md) with `EventSourcedBehavior`s is based on the single writer principle, which means that there can only be one active instance of a `EventSourcedBehavior` with a given `persistenceId`. Otherwise, multiple instances would store interleaving events based on different states, and when these events would later be replayed it would not be possible to reconstruct the correct state.
@ref[Event sourcing](./persistence.md) with `EventSourcedBehavior`s is based on the single writer principle, which means that there can only be one active instance of a `EventSourcedBehavior`
with a given `persistenceId`. Otherwise, multiple instances would store interleaving events based on different states, and when these events would later be replayed it would not be possible to reconstruct the correct state.
This restriction means that in the event of network partitions, and for a short time during rolling re-deploys, some
`EventSourcedBehavior` actors are unavailable.
@ -28,7 +29,7 @@ The motivations are:
* Balance the load over many servers
However, the event handler must be able to **handle concurrent events** as when replication is enabled
there is no longer the single writer principle as there is with a normal `EventSourcedBehavior`.
the single-writer guarantee is not maintained like it is with a normal `EventSourcedBehavior`.
The state of a replicated `EventSourcedBehavior` is **eventually consistent**. Event replication may be delayed
due to network partitions and outages, which means that the event handler and those reading the state must be designed
@ -36,7 +37,7 @@ to handle this.
To be able to use Replicated Event Sourcing the journal and snapshot store used is required to have specific support for the metadata that the replication needs (see @ref[Journal Support](#journal-support)).
## Relaxing the single writer principle for availability
## Relaxing the single-writer principle for availability
Taking the example of using Replicated Event Sourcing to run a replica per data center.