The statisticservice is the Backend for the https://github.com/w3champions/w3champions-ui Project. Among the data for the website it also provides the chat backend that is used from the ingame client and the clan functions.
You will need a mongodb to run the service. If you do not have a local mongo container, spin one up with
docker run mongo
and your local service should be able to connect to this default mongo address. The default is our open test db with connectionstring mongodb://157.90.1.251:3513
If you have your own MongoDb, you need to run the service with a Env Variable Called "MONGO_CONNECTION_STRING" and set it to the corresponding connection string. You can also just replace the line in the Program.cs with your own connection string.
CAUTION: When running locally, the readmodel handling is turned off, unless you set the corresponding env variable. But only do that, if you know what you are doing. You can end up overwriting data from prod/test, depending on where you are connected. So always make sure the handlers are turned off, or you have breakpoints set before you save any data. (more to readmodels below).
The readmodels for the DB are being generated from the event that the matchmaking service generates. After a match, the matchmaking service pushes an event to the collection "MatchFinishedEvent". For every readmodel that we have, we read the latest event and transform it into the model for the website. Like that we also generate statistics that are bigger and would be too costly to calculate every time we enter the page (like the hero vs her stats for example). This also decouples the matchmaking service from the stuff that we need to show on the website.
CAUTION: When running locally, the readmodel handling is turned off, unless you set the corresponding env variable. But only do that, if you know what you are doing. You can end up overwriting data from prod/test, depending on where you are connected. So always make sure the handlers are turned off, or you have breakpoints set before you save any data.
The easiest way to fix models is to just recreate them from scratch. There is a flag in the HandlerVersion collection called Stopped for each handler, that you can put to true if you want the handler to stop. After that delete the corresponding collection and the handler version. Within the next 5 seconds the service should start from 0 again. Depending on the readmodel this might take a while (max 1h), so do this during off times, because the data will be bad within this time. You can not just delete the HandlerVersion, as for many statistics, we count the events. For example, if you replay the model for Player Games and you just delete the HandlerVersion, you will count old games twice. You can also delete data from one season only and then set the HandlerVersion to the first event within a season, to save some time. But this obviously is more hassle and deleting works just fine.
Those are the default Handlers and you can implement one like so
public class PlayerWinrateHandler : IReadModelHandler
{
private readonly IPlayerRepository _playerRepository;
public PlayerWinrateHandler(
IPlayerRepository playerRepository
)
{
_playerRepository = playerRepository;
}
public async Task Update(MatchFinishedEvent nextEvent) // this is the method you need to implement
{
var playerMMrChanges = nextEvent.match.players;
var winrateTasks = playerMMrChanges.Select(async p => await LoadAndApply(p, nextEvent.match.season));
var newWinrates = (await Task.WhenAll(winrateTasks)).ToList();
await _playerRepository.UpsertWins(newWinrates);
}
}
As you can see you need to make the transformation and save the readmodel in our database. The convention was always
that we call the handler like the readmodel. In that case PlayerWinrateHandler and PlayerWinrate, so it is
easier to find the collection to the handler.
Also the handling framework saves the version of the last save event, when the function returns. (See
ReadModelHandler class for details). The version is saved in the collection HandlerVersions. So it makes sens
to take a look at the versions from time to time. If they differ and do not move, it is likely that a handler is
throwing exceptions and is stuck. The retry time is every 5 seconds.
We also have unversioned handlers for stuff that is not tight to an event. For example the Rankings are also pushed
to the database after a match and we load all of them in a handler, transform all ranks and then save all of them to
our readmodel db. That is usually not needed, but the interface for that is IAsyncUpdatable. This function is
called every 5 seconds as well and you can do whatever you want in there periodically. Like a CRON job for poor
people ;)
To run the service locally with data, you will need to install:
- MongoDB
- MongoDB Database Tools
- MongoDB Compass (not necessary but recommended)
There is a dump of the W3Champions production database from Season 11 here: https://drive.google.com/drive/folders/1mfH_jECJI6kisaA0uBDsXkYxk42FcRF9
Note that the MatchFinishedEvents collection is separate. This collection is only useful if you plan to work on pre-S10 match results pages.
Download the collections and put them in a folder dump then to import it, run:
mongorestore --uri="mongodb://localhost:27017" dump/
We also have an open tests db here, but be warned it may be unstable due to people adding new properties or collections, feel free to edit it as you require, or run integration tests against it mongodb://157.90.1.251:3512
If you need access to the test environment database, ask a Dev and they can give you the connection string.
To run integration tests against the local database, edit this line:
Warning: this WILL drop your local database, so be warned!
If you branch starts with "DEPLOY_" azure will create a automatic deployment for your pull request, so you can test it in an isolated environment. It will be deployed to whatever comes after "DEPLOY_". For example, if my branch is called DEPLOY_add-new-language the pr will be published to https://statistic-service-add-new-language.pr.w3champions.com. The https certificate will be generated after the deployment, but this can take some time.
If you need any other connection strings, just update the docker-compose.token.yaml file accordingliy, for example if you want to use a different backend for the identification for example (which can also be deployed by a PR just like this repo).
When you are done, please contact one of the older devs, because they can delete the unused containers again.