These are chat archives for akkadotnet/akka.net

12th
Oct 2017
Michel van den Berg
@promontis
Oct 12 2017 09:32
I'm having trouble to inject a specific HOCON config for my cluster-sharding section into my persistence plugin. When I look at other implementations of persistence plugins, I see two flavors: a constructor with and without a config parameter. Eg. SqliteJournal (https://github.com/akkadotnet/akka.net/blob/1595e1e832fb42b4a70a4ebf0b3dc52b87b40a96/src/contrib/persistence/Akka.Persistence.Sqlite/Journal/SqliteJournal.cs) has public SqliteJournal(Config journalConfig), whereas other persistence plugins do not provide the Config parameter. What's the deal with the Config parameter? Will the cluster sharding plugin inject the current config into the persistence plugin via that ctor?
Arjen Smits
@Danthar
Oct 12 2017 12:24
@promontis check out the cluster sharding settings
it uses a journal-plugin-id and snapshot-plugin-id setting which contains the absolute path to the journal or snapshot plugin config entity
if you dont define that it uses the system default (whatever you have defined)
So in short cluster sharding does not initialise the persistence plugin. Its reponsible for doing that itself. In short through its respective hocon config or manually before you intialise the cluster sharding system
The Config parameter is there to allow you to manually provide override configs or a while config yourself.
If you dont define anything it will fallback to whatever is in the hocon config
And its also used for testing :P
@jackowild we probably already seen your PR come up. but I forwarded your request internally as well. Can't make any promises as to when someone will get around to it though.
Michel van den Berg
@promontis
Oct 12 2017 13:10
@Danthar but how does the cluster sharding plugin tell the persistence plugin which config to use? I mean, if I look at the persistence plugins they all know how to persist to a journal using the default journal config (eg. akka.persistence.journal.sql-server). They do not check the config for the cluster setting, so how does the cluster sharding persistence config (as configured via the journal-plugin-id, as you said) flow to the persistence plugin?
For example, this plugin (https://github.com/alexvaluyskiy/Akka.Persistence.Azure/blob/dev/src/Akka.Persistence.AzureTable/AzureTablePersistence.cs#L85) always uses the same config section 'akka.persistence.journal.azure-table' for its persistence. It seems not able to get a different config for eg cluster sharding. This means both normal actor state and cluster sharding state will end up in the same table (as configured by that one config section)
with the sql-server persistence plugin it seems to work when I configure it like this (https://github.com/promontis/stylister.sample/blob/master/Liking/Stylister.Liking.Downloader/settings.hocon), but I don't get how the akka.persistence.journal.sharding config section is passed to the sql-server persistence plugin
Arjen Smits
@Danthar
Oct 12 2017 13:59
eh. I dont understand your question. Because you answered it yourself already ?
Michel van den Berg
@promontis
Oct 12 2017 14:00
haha
Arjen Smits
@Danthar
Oct 12 2017 14:01
Wellicht PM even snel ?
Michel van den Berg
@promontis
Oct 12 2017 14:01
sure :)
Jack Wild
@jackowild
Oct 12 2017 14:12
thanks @Danthar , I'm not sure how the build/CI process works so will need some help with that when one of you gets round to it :+1:
Michal Dabrowski
@defrag2_twitter
Oct 12 2017 15:16
Hey guys, question: whenever using a supervising actor for persistent actor (in case where they cannot really be
created or recreated on demand), is the approach of creating actors while replaying event mentioned in "akka in action"
book (https://github.com/RayRoestenburg/akka-in-action/blob/master/chapter-persistence/src/main/scala/aia/persistence/ShoppersSingleton.scala#L71)
the best way to go? Or some streaming from some other source would be more applicable?
Ricardo Abreu
@codenakama
Oct 12 2017 22:50

hey guys. I have this scenario where I need to able to do things like determining for a given user: nearby shops, distance from a shop, distance and time away from delivery person/courier.

For this I decided to create a "Locations Service" and the idea is to have other services actors make requests to it to get location related data using Akka.Remote .

For example: Shop Service asks locationsService which are the nearby shops for a given point/user location (latitude, longitude). My problem is that currently I have the dbs separated by each service. How would shop service know which shops to present to the user? Right now all I have is geo spatial data stored in locations service db and a name for each entry. I feel like I'm missing something and I might be even confusing myself :/

Ricardo Abreu
@codenakama
Oct 12 2017 22:56
maybe I should kill the locations service and have each service that requires location handle their own spatial data queries without having to call a separate service