uid | title |
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akkadotnet-v15-upgrade-advisories |
Akka.NET v1.5 Upgrade Advisories |
This document contains specific upgrade suggestions, warnings, and notices that you will want to pay attention to when upgrading between versions within the Akka.NET v1.5 roadmap.
One of the most significant upgrades we've made in Akka.NET v1.5 is a complete rewrite of Akka.Cluster.Sharding's state storage system.
Note
You can watch our discussion of this Akka.Cluster.Sharding upgrade during our September, 2022 Akka.NET Community Standup for more details.
In Akka.NET v1.5 we've split Akka.Cluster.Sharding's state-store-mode
into two parts:
- CoordinatorStore (
akka.cluster.sharding.state-store-mode
) and - ShardStore (
akka.cluster.sharding.remember-entities-store
.)
Which can use different persistence modes configured via akka.cluster.sharding.state-store-mode
& akka.cluster.sharding.remember-entities-store
.
Important
The goal behind this split was to remove the ShardCoordinator
as a single point of bottleneck during remember-entities=on
recovery - in Akka.NET v1.4 all remember-entity state is concentrated in the journal of the PersistentShardCoordinator
or the CRDT used by the DDataCoordinator
. In v1.5 the responsibility for remembering entities has been pushed to the Shard
actors themselves, which allows for remembered-entities to be recovered in parallel for all shards.
Possible combinations:
state-store-mode | remember-entities-store | CoordinatorStore mode | ShardStore mode |
---|---|---|---|
persistence (default) | - (ignored) | persistence | persistence |
ddata | ddata | ddata | ddata |
ddata | eventsourced (new) | ddata | persistence |
There should be no breaking changes from user perspective. Only some internal messages/objects were moved. There should be no change in the PersistentId
behavior and default persistent configuration (akka.cluster.sharding.state-store-mode
)
This change is designed to speed up the performance of Akka.Cluster.Sharding coordinator recovery by moving remember-entities
recovery into separate actors - this also solves major performance problems with the ddata
recovery mode overall.
The recommended settings for maximum ease-of-use for Akka.Cluster.Sharding in new applications going forward will be:
akka.cluster.sharding{
state-store-mode = ddata
remember-entities-store = eventsourced
}
However, for the sake of backwards compatibility the Akka.Cluster.Sharding defaults have been left as-is:
akka.cluster.sharding{
state-store-mode = persistence
# remember-entities-store (not set - also uses legacy Akka.Persistence)
}
Note
This section applies only to users who were using akka.cluster.sharding.state-store-mode = persistence
. If you were using akka.cluster.sharding.state-store-mode
Switching over to using remember-entities-store = eventsourced
will cause an initial migration of data from the ShardCoordinator
's journal into separate event journals going forward.
Upgrading to Akka.NET v1.5 will cause an irreversible migration of Akka.Cluster.Sharding data for users who were previously running akka.cluster.state-store-mode=persistence
, so follow the steps below carefully:
Important
This migration is intended to be performed via upgrading Akka.NET to v1.5 and applying HOCON configuration changes - it requires no downtime.
Update your Akka.Cluster.Sharding HOCON to look like the following (adjust as necessary for your custom settings):
akka.cluster.sharding {
remember-entities = on
remember-entities-store = "eventsourced"
state-store-mode = "persistence"
# fail if upgrade doesn't succeed
fail-on-invalid-entity-state-transition = on
}
akka.persistence.journal.{your-journal-implementation} {
event-adapters {
coordinator-migration = ""Akka.Cluster.Sharding.OldCoordinatorStateMigrationEventAdapter, Akka.Cluster.Sharding""
}
event-adapter-bindings {
""Akka.Cluster.Sharding.ShardCoordinator+IDomainEvent, Akka.Cluster.Sharding"" = coordinator-migration
}
}
Note
If you don't run Akka.Cluster.Sharding with remember-entities=on
normally then there is no need to turn it on here.
With these HOCON settings in-place the following will happen:
- The old
PersitentShardCoordinator
state will be broken up -remember-entities=on
data will be distributed to each of thePersistentShard
actors, who will now use the newremember-entities-store = "eventsourced"
setting going forward; - Old
Akka.Cluster.Sharding.ShardCoordinator+IDomainEvent
will be upgraded to a new storage format via thecoordinator-migration
Akka.Persistence event adapter; and - The
PersistentShardCoordinator
will migrate its journal to the new format as well.
Once your cluster has successfully booted up with these settings, you can now optionally move to using DData
as your akka.cluster.sharding.state-store-mode
by deploying a second time with the following HOCON:
akka.cluster.sharding {
remember-entities = on
remember-entities-store = "eventsourced"
state-store-mode = "ddata"
# fail if upgrade doesn't succeed
fail-on-invalid-entity-state-transition = on
}
akka.persistence.journal.{your-journal-implementation} {
event-adapters {
coordinator-migration = ""Akka.Cluster.Sharding.OldCoordinatorStateMigrationEventAdapter, Akka.Cluster.Sharding""
}
event-adapter-bindings {
""Akka.Cluster.Sharding.ShardCoordinator+IDomainEvent, Akka.Cluster.Sharding"" = coordinator-migration
}
}
Now you'll be running Akka.Cluster.Sharding with the recommended settings.
The migration process onto Akka.NET v1.5's new Cluster.Sharding storage system is less involved for users who were already using akka.cluster.sharding.state-store-mode=ddata
.
All these users need to do this:
- Setup an
akka.persistence.journal
andakka.persistence.snapshot-store
to use withakka.cluster.sharding.remember-entities-store = eventsourced
; - Deploy using the following HOCON:
akka.cluster.sharding {
remember-entities = on
remember-entities-store = "eventsourced"
state-store-mode = "ddata"
# fail if upgrade doesn't succeed
fail-on-invalid-entity-state-transition = on
}
akka.persistence.journal.{your-journal-implementation} {
event-adapters {
coordinator-migration = ""Akka.Cluster.Sharding.OldCoordinatorStateMigrationEventAdapter, Akka.Cluster.Sharding""
}
event-adapter-bindings {
""Akka.Cluster.Sharding.ShardCoordinator+IDomainEvent, Akka.Cluster.Sharding"" = coordinator-migration
}
}
If you run into any trouble upgrading, please file an issue with Akka.NET.
In v1.5, we've re-engineering the ILoggingAdapter
construct to be more extensible and performant. Unfortunately this necessitate some breaking changes that will affect end-user code - but the remedy for those changes is trivial.
After installing the v1.5 NuGet packages into your applications or libraries, you will need to add the following to all of your source files where you previously made calls to the ILoggingAdapter
:
using Akka.Event;
That using
statement will pull in the extension methods that match all of the v1.4 API ILoggingAdapter
signatures in v1.5.
Even better - if you can take advantage of global using
statements in C#10, then this is a one-liner as either the MSBuild or project level:
In Directory.Build.props
:
<Project>
<ItemGroup>
<PackageReference Include="Akka" />
<Using Include="Akka.Event" />
</ItemGroup>
</Project>