Help needed with background jobs and context injection

[franck102]

Hi all, I need to run some background tasks on startup and those tasks need to access request scoped beans and contextual data. My current approach kind of works, but I am pretty sure that there must be a better / simpler way to achieve this.

My background tasks are started like this:

     ...
    @Inject
    RoutingContext _routingContext;

    @Inject
    Vertx _vertx;

    void onStart(@Observes StartupEvent ev)
    {
        Context context = _vertx.getOrCreateContext();
        if (context.isEventLoopContext()) {
            context = ((ContextInternal) context).duplicate();
        }
        for (String tenantId : _coreStore.listTenants()) {
            context.executeBlocking(call -> {
                try {
                    startGateway(tenantId);
                    call.complete();
                }
                catch (Throwable t) {
                    _log.error("Could not start payment gateway for tenant " + tenantId, t);
                    call.fail(t);
                }
            });
        }
    }

    @ActivateRequestContext
    public void startGateway(String tenantId)
    {
        // _routingContext.put(CoreUtils.KEY_TENANT_ID, tenantId);
        // _tenantHolder.setTenantId(tenantId);
        Vertx.currentContext().putLocal(CoreUtils.KEY_TENANT_ID, tenantId);
        EPSettings settings = _coreStore.getTenantSettings(tenantId).getPaymentSettings();
        _gatewayFactory.getPaymentGateway(tenantId).start(tenantId, settings);
    }

and I have a tenant resolver that was initially written for HTTP requests, and which I modified to also check the Vertx context:

@ApplicationScoped
public class TenantResolver
{
    @Inject
    RoutingContext _routingContext;

    protected String tenantId()
    {
        Object value = null;
        try {
            Context context = Vertx.currentContext();
            value = context == null ? null : context.getLocal(CoreUtils.KEY_TENANT_ID);
        }
        catch (InjectionException e) {
            // Ignore and proceed with routing context.
        }

        if (value == null) {
            value = _routingContext.get(CoreUtils.KEY_TENANT_ID);
        }
        if (value == null) {
            throw new ServiceException(403, ErrorCode.TenantMissing);
        }
        return value.toString();
    }
}

I am not very clear about the @ActivateRequestContext, what context instances will that allow me to use? Trying to use _routingContext.put() in startGateway fails, I guess the context is only created for HTTP requests?

I tried using my own request scoped bean, but I don't know how to correctly access it from my tenant resolver:

@RequestScoped
public class TenantHolder
{
    private String _tenantId;
    public String getTenantId() { return _tenantId; }
    public void setTenantId(String tenantId) { _tenantId = tenantId; }
}

@ApplicationScoped
@Unremovable
public class EpTenantConfigResolver implements TenantConfigResolver
{
    @Inject
    TenantHolder _tenantHolder;

    @Override
    public Uni<OidcTenantConfig> resolve(RoutingContext context, OidcRequestContext<OidcTenantConfig> requestContext)
    {
        String tenantId = _getTargetTenant(context.request());
        if (tenantId != null) {
            // context.put(CoreUtils.KEY_TENANT_ID, tenantId);
            _tenantHolder.setTenantId(tenantId); -> fails since the resolver is ApplicationScoped

I could definitely use some pointers about the correct design here!
Thanks,
Franck

[quarkus-bot[bot]]

/cc @Ladicek (arc), @manovotn (arc), @mkouba (arc)

[mkouba]

Hi @franck102, do you need to execute the startGateway() logic on the Vertx event loop? If so then the VertxContextSupport.subscribeAndAwait() util method might come in useful. It also starts the CDI request context if not already active.

I am not very clear about the @ActivateRequestContext, what context instances will that allow me to use? Trying to use _routingContext.put() in startGateway fails, I guess the context is only created for HTTP requests?

Yes, the io.vertx.ext.web.RoutingContext is not available outside an HTTP request.

_tenantHolder.setTenantId(tenantId); -> fails since the resolver is ApplicationScoped

This should work just fine because the injected _tenantHolder is a client proxy that delegates invocations to the current instance of TenantHolder (if the request context is active).

[mkouba]

Hi @mkouba , the tasks are potentially long-running (calls to external payment providers) so if I read the Vertx docs correctly I should not run them on the event loop.

Well, it depends whether you're using blocking or non-blocking APIs. If using blocking APIs then you should definitely not execute the logic on the event loop.

Why exactly do you duplicate the vertx context? It's not a public API so

Can't you just @Inject Vertx and then use Vertx.executeBlocking()? Do you even need to execute the logic on a Vertx context?

Note that you can also @Inject ExecutorService, i.e. the default blocking executor, which is backed by Vertx worker threads (if Vertx extension is present).

[franck102]

Why exactly do you duplicate the vertx context? It's not a public API so

Can't you just @Inject Vertx and then use Vertx.executeBlocking()? Do you even need to execute the logic on a Vertx context?

Note that you can also @Inject ExecutorService, i.e. the default blocking executor, which is backed by Vertx worker threads (if Vertx extension is present).

I was duplicating the context earlier to be able to use putLocal (fails on the root context) which is how I was passing the tenantId around.

Maybe I could use ExecutorService, but reading through quite a few dozens of posts / docs I couldn't figure out whether executeBlocking or the ExecutorService made more sense.
Then there is the ManagedExecutor too... all I know is I need context propagation (the tasks use the DB layer), and the tasks should run on worker threads.

[franck102]

Note that you can also @Inject ExecutorService, i.e. the default blocking executor, which is backed by Vertx worker threads (if Vertx extension is present).

I just tried the default ManagedExecutor and injection of the RequestScoped bean is failing - it seems the ActivateRequestContext annotation has no effect.

 @Inject
    ManagedExecutor _executor;

    void onStart(@Observes StartupEvent ev)
    {
        for (String tenantId : _coreStore.listTenants()) {
            _executor.runAsync(() -> {
                try {
                    startGateway(tenantId);
                }
                catch (Throwable t) {
                    _log.error("Could not start payment gateway for tenant " + tenantId, t);
                }
            });
        }
    }

    @ActivateRequestContext
    public void startGateway(String tenantId)
    {
        _tenantHolder.setTenantId(tenantId);

The exception is

15:17:03 ERROR [co.pa.pa.se.PaymentService] (executor-thread-1) Could not start payment gateway for tenant totem: jakarta.enterprise.inject.IllegalProductException: Normal scoped producer method may not return null: io.quarkus.vertx.http.runtime.CurrentVertxRequest.getCurrent()
	at io.quarkus.vertx.http.runtime.CurrentVertxRequest_ProducerMethod_getCurrent_6dc23d16d53ba5c34e1e7b6f54290fd7b9aebd76_Bean.doCreate(Unknown Source)
	at io.quarkus.vertx.http.runtime.CurrentVertxRequest_ProducerMethod_getCurrent_6dc23d16d53ba5c34e1e7b6f54290fd7b9aebd76_Bean.create(Unknown Source)
	at io.quarkus.vertx.http.runtime.CurrentVertxRequest_ProducerMethod_getCurrent_6dc23d16d53ba5c34e1e7b6f54290fd7b9aebd76_Bean.create(Unknown Source)
	at io.quarkus.arc.impl.RequestContext.getIfActive(RequestContext.java:74)

[mkouba]

The exception is...

Well, if you look at the error message it seems that it's not about inactive request context but the fact that something attempts to inject the RoutingContext which is not legal outside an HTTP request as explained earlier...

[franck102]

The exception is...

Well, if you look at the error message it seems that it's not about inactive request context but the fact that something attempts to inject the RoutingContext which is not legal outside an HTTP request as explained earlier...

You are right, TenantHolder.setTenantId() succeeds in startGateway, but when the TenantHolder is later injected in the task it's a different instance that hasn't been initialized.
getTenantId() seeing no explicit _tenantId defaults to using the RoutingContext which triggers the exception.

Using Vertx.executeBlocking I don't have that problem.

The task code is blocking and it is executed on a single thread.

[franck102]

I cannot use a RequestScoped bean in my OIDC TenantConfigResolver because the request context is not started yet when resolve() is called. So I am still putting the tenant on the RoutingContext there, then using this RequestScoped bean:

@RequestScoped
public class TenantHolder
{
    @Inject
    RoutingContext _routingContext;

    private String _tenantId;

    public String getTenantId()
    {
        return _tenantId != null ? _tenantId :
                _routingContext.get(CoreUtils.KEY_TENANT_ID);
    }

    public void setTenantId(String tenantId)  { _tenantId = tenantId;  }
}

With that I can simplify the Vertx code to use whatever context is available.