io.vertx.reactivex.servicediscovery

Class ServiceDiscovery

java.lang.Object

io.vertx.reactivex.servicediscovery.ServiceDiscovery

public class ServiceDiscovery
extends Object

Service Discovery main entry point.

The service discovery is an infrastructure that let you publish and find `services`. A `service` is a discoverable functionality. It can be qualified by its type, metadata, and location. So a `service` can be a database, a service proxy, a HTTP endpoint. It does not have to be a vert.x entity, but can be anything. Each service is described by a Record.

The service discovery implements the interactions defined in the service-oriented computing. And to some extend, also provides the dynamic service-oriented computing interaction. So, application can react to arrival and departure of services.

A service provider can:

* publish a service record * un-publish a published record * update the status of a published service (down, out of service...)

A service consumer can:

* lookup for services * bind to a selected service (it gets a ServiceReference) and use it * release the service once the consumer is done with it * listen for arrival, departure and modification of services.

Consumer would 1) lookup for service record matching their need, 2) retrieve the ServiceReference that give access to the service, 3) get a service object to access the service, 4) release the service object once done.

A state above, the central piece of information shared by the providers and consumers are Record.

Providers and consumers must create their own ServiceDiscovery instance. These instances are collaborating in background (distributed structure) to keep the set of services in sync.

NOTE: This class has been automatically generated from the original non RX-ified interface using Vert.x codegen.

Field Summary

Fields

Modifier and Type	Field and Description
static io.vertx.lang.rx.TypeArg<ServiceDiscovery>	__TYPE_ARG

Constructor Summary

Constructors

Constructor and Description
ServiceDiscovery(Object delegate)
ServiceDiscovery(ServiceDiscovery delegate)

Method Summary

Modifier and Type	Method and Description
Set<ServiceReference>	bindings()
void	close() Closes the service discovery
static ServiceDiscovery	create(Vertx vertx) Creates a new instance of ServiceDiscovery using the default configuration.
static ServiceDiscovery	create(Vertx vertx, ServiceDiscoveryOptions options) Creates an instance of ServiceDiscovery.
boolean	equals(Object o)
ServiceDiscovery	getDelegate()
void	getRecord(java.util.function.Function<Record,Boolean> filter) Lookups for a single record.
void	getRecord(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService) Lookups for a single record.
void	getRecord(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService, Handler<AsyncResult<Record>> resultHandler) Lookups for a single record.
void	getRecord(java.util.function.Function<Record,Boolean> filter, Handler<AsyncResult<Record>> resultHandler) Lookups for a single record.
void	getRecord(JsonObject filter) Lookups for a single record.
void	getRecord(JsonObject filter, Handler<AsyncResult<Record>> resultHandler) Lookups for a single record.
void	getRecord(String id) Looks up for a single record by its registration id.
void	getRecord(String id, Handler<AsyncResult<Record>> resultHandler) Looks up for a single record by its registration id.
void	getRecords(java.util.function.Function<Record,Boolean> filter) Lookups for a set of records.
void	getRecords(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService) Lookups for a set of records.
void	getRecords(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService, Handler<AsyncResult<List<Record>>> resultHandler) Lookups for a set of records.
void	getRecords(java.util.function.Function<Record,Boolean> filter, Handler<AsyncResult<List<Record>>> resultHandler) Lookups for a set of records.
void	getRecords(JsonObject filter) Lookups for a set of records.
void	getRecords(JsonObject filter, Handler<AsyncResult<List<Record>>> resultHandler) Lookups for a set of records.
ServiceReference	getReference(Record record) Gets a service reference from the given record.
ServiceReference	getReferenceWithConfiguration(Record record, JsonObject configuration) Gets a service reference from the given record, the reference is configured with the given json object.
int	hashCode()
static ServiceDiscovery	newInstance(ServiceDiscovery arg)
ServiceDiscoveryOptions	options()
void	publish(Record record) Publishes a record.
void	publish(Record record, Handler<AsyncResult<Record>> resultHandler) Publishes a record.
ServiceDiscovery	registerServiceExporter(ServiceExporter exporter, JsonObject configuration) Registers a discovery bridge.
ServiceDiscovery	registerServiceExporter(ServiceExporter exporter, JsonObject configuration, Handler<AsyncResult<Void>> completionHandler) Registers a discovery bridge.
ServiceDiscovery	registerServiceImporter(ServiceImporter importer, JsonObject configuration) Registers a discovery service importer.
ServiceDiscovery	registerServiceImporter(ServiceImporter importer, JsonObject configuration, Handler<AsyncResult<Void>> completionHandler) Registers a discovery service importer.
boolean	release(ServiceReference reference) Releases the service reference.
static void	releaseServiceObject(ServiceDiscovery discovery, Object svcObject) Release the service object retrieved using get methods from the service type interface.
Maybe<Record>	rxGetRecord(java.util.function.Function<Record,Boolean> filter) Lookups for a single record.
Maybe<Record>	rxGetRecord(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService) Lookups for a single record.
Maybe<Record>	rxGetRecord(JsonObject filter) Lookups for a single record.
Maybe<Record>	rxGetRecord(String id) Looks up for a single record by its registration id.
Single<List<Record>>	rxGetRecords(java.util.function.Function<Record,Boolean> filter) Lookups for a set of records.
Single<List<Record>>	rxGetRecords(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService) Lookups for a set of records.
Single<List<Record>>	rxGetRecords(JsonObject filter) Lookups for a set of records.
Single<Record>	rxPublish(Record record) Publishes a record.
Completable	rxRegisterServiceExporter(ServiceExporter exporter, JsonObject configuration) Registers a discovery bridge.
Completable	rxRegisterServiceImporter(ServiceImporter importer, JsonObject configuration) Registers a discovery service importer.
Completable	rxUnpublish(String id) Un-publishes a record.
Single<Record>	rxUpdate(Record record) Updates the given record.
String	toString()
void	unpublish(String id) Un-publishes a record.
void	unpublish(String id, Handler<AsyncResult<Void>> resultHandler) Un-publishes a record.
void	update(Record record) Updates the given record.
void	update(Record record, Handler<AsyncResult<Record>> resultHandler) Updates the given record.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

__TYPE_ARG

public static final io.vertx.lang.rx.TypeArg<ServiceDiscovery> __TYPE_ARG

Constructor Detail

ServiceDiscovery

public ServiceDiscovery(ServiceDiscovery delegate)

ServiceDiscovery

public ServiceDiscovery(Object delegate)

Method Detail

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

getDelegate

public ServiceDiscovery getDelegate()

create

public static ServiceDiscovery create(Vertx vertx,
                                      ServiceDiscoveryOptions options)

Creates an instance of ServiceDiscovery.

Parameters:

vertx - the vert.x instance

options - the discovery options

Returns:

the created service discovery instance.

create

public static ServiceDiscovery create(Vertx vertx)

Creates a new instance of ServiceDiscovery using the default configuration.

Parameters:

vertx - the vert.x instance

Returns:

the created instance

getReference

public ServiceReference getReference(Record record)

Gets a service reference from the given record.

Parameters:

record - the chosen record

Returns:

the service reference, that allows retrieving the service object. Once called the service reference is cached, and need to be released.

getReferenceWithConfiguration

public ServiceReference getReferenceWithConfiguration(Record record,
                                                      JsonObject configuration)

Gets a service reference from the given record, the reference is configured with the given json object.

Parameters:

record - the chosen record

configuration - the configuration

Returns:

the service reference, that allows retrieving the service object. Once called the service reference is cached, and need to be released.

release

public boolean release(ServiceReference reference)

Releases the service reference.

Parameters:

reference - the reference to release, must not be null

Returns:

whether or not the reference has been released.

registerServiceImporter

public ServiceDiscovery registerServiceImporter(ServiceImporter importer,
                                                JsonObject configuration,
                                                Handler<AsyncResult<Void>> completionHandler)

Registers a discovery service importer. Importers let you integrate other discovery technologies in this service discovery.

Parameters:

importer - the service importer

configuration - the optional configuration

completionHandler - handler call when the importer has finished its initialization and initial imports

Returns:

the current ServiceDiscovery

registerServiceImporter

public ServiceDiscovery registerServiceImporter(ServiceImporter importer,
                                                JsonObject configuration)

Registers a discovery service importer. Importers let you integrate other discovery technologies in this service discovery.

Parameters:

importer - the service importer

configuration - the optional configuration

Returns:

the current ServiceDiscovery

rxRegisterServiceImporter

public Completable rxRegisterServiceImporter(ServiceImporter importer,
                                             JsonObject configuration)

Registers a discovery service importer. Importers let you integrate other discovery technologies in this service discovery.

Parameters:

importer - the service importer

configuration - the optional configuration

Returns:

the current ServiceDiscovery

registerServiceExporter

public ServiceDiscovery registerServiceExporter(ServiceExporter exporter,
                                                JsonObject configuration,
                                                Handler<AsyncResult<Void>> completionHandler)

Registers a discovery bridge. Exporters let you integrate other discovery technologies in this service discovery.

Parameters:

exporter - the service exporter

configuration - the optional configuration

completionHandler - handler notified when the exporter has been correctly initialized.

Returns:

the current ServiceDiscovery

registerServiceExporter

public ServiceDiscovery registerServiceExporter(ServiceExporter exporter,
                                                JsonObject configuration)

Registers a discovery bridge. Exporters let you integrate other discovery technologies in this service discovery.

Parameters:

exporter - the service exporter

configuration - the optional configuration

Returns:

the current ServiceDiscovery

rxRegisterServiceExporter

public Completable rxRegisterServiceExporter(ServiceExporter exporter,
                                             JsonObject configuration)

Registers a discovery bridge. Exporters let you integrate other discovery technologies in this service discovery.

Parameters:

exporter - the service exporter

configuration - the optional configuration

Returns:

the current ServiceDiscovery

close

public void close()

Closes the service discovery

publish

public void publish(Record record,
                    Handler<AsyncResult<Record>> resultHandler)

Publishes a record.

Parameters:

record - the record

resultHandler - handler called when the operation has completed (successfully or not). In case of success, the passed record has a registration id required to modify and un-register the service.

publish

public void publish(Record record)

Publishes a record.

Parameters:

record - the record

rxPublish

public Single<Record> rxPublish(Record record)

Publishes a record.

Parameters:

record - the record

Returns:

unpublish

public void unpublish(String id,
                      Handler<AsyncResult<Void>> resultHandler)

Un-publishes a record.

Parameters:

id - the registration id

resultHandler - handler called when the operation has completed (successfully or not).

unpublish

public void unpublish(String id)

Un-publishes a record.

Parameters:

id - the registration id

rxUnpublish

public Completable rxUnpublish(String id)

Un-publishes a record.

Parameters:

id - the registration id

Returns:

getRecord

public void getRecord(JsonObject filter,
                      Handler<AsyncResult<Record>> resultHandler)

Lookups for a single record.

Filters are expressed using a Json object. Each entry of the given filter will be checked against the record. All entry must match exactly the record. The entry can use the special "*" value to denotes a requirement on the key, but not on the value.

Let's take some example:

   { "name" = "a" } => matches records with name set fo "a"
   { "color" = "*" } => matches records with "color" set
   { "color" = "red" } => only matches records with "color" set to "red"
   { "color" = "red", "name" = "a"} => only matches records with name set to "a", and color set to "red"
 

If the filter is not set (null or empty), it accepts all records.

This method returns the first matching record.

Parameters:

filter - the filter.

resultHandler - handler called when the lookup has been completed. When there are no matching record, the operation succeeds, but the async result has no result (null).

getRecord

public void getRecord(JsonObject filter)

Lookups for a single record.

Filters are expressed using a Json object. Each entry of the given filter will be checked against the record. All entry must match exactly the record. The entry can use the special "*" value to denotes a requirement on the key, but not on the value.

Let's take some example:

   { "name" = "a" } => matches records with name set fo "a"
   { "color" = "*" } => matches records with "color" set
   { "color" = "red" } => only matches records with "color" set to "red"
   { "color" = "red", "name" = "a"} => only matches records with name set to "a", and color set to "red"
 

If the filter is not set (null or empty), it accepts all records.

This method returns the first matching record.

Parameters:

filter - the filter.

rxGetRecord

public Maybe<Record> rxGetRecord(JsonObject filter)

Lookups for a single record.

Filters are expressed using a Json object. Each entry of the given filter will be checked against the record. All entry must match exactly the record. The entry can use the special "*" value to denotes a requirement on the key, but not on the value.

Let's take some example:

   { "name" = "a" } => matches records with name set fo "a"
   { "color" = "*" } => matches records with "color" set
   { "color" = "red" } => only matches records with "color" set to "red"
   { "color" = "red", "name" = "a"} => only matches records with name set to "a", and color set to "red"
 

If the filter is not set (null or empty), it accepts all records.

This method returns the first matching record.

Parameters:

filter - the filter.

Returns:

getRecord

public void getRecord(String id,
                      Handler<AsyncResult<Record>> resultHandler)

Looks up for a single record by its registration id.

When there are no matching record, the operation succeeds, but the async result has no result (null).

Parameters:

id - the registration id

resultHandler - handler called when the lookup has been completed

getRecord

public void getRecord(String id)

Looks up for a single record by its registration id.

When there are no matching record, the operation succeeds, but the async result has no result (null).

Parameters:

id - the registration id

rxGetRecord

public Maybe<Record> rxGetRecord(String id)

Looks up for a single record by its registration id.

When there are no matching record, the operation succeeds, but the async result has no result (null).

Parameters:

id - the registration id

Returns:

getRecord

public void getRecord(java.util.function.Function<Record,Boolean> filter,
                      Handler<AsyncResult<Record>> resultHandler)

Lookups for a single record.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

This method only looks for records with a UP status.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

resultHandler - the result handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has no result.

getRecord

public void getRecord(java.util.function.Function<Record,Boolean> filter)

Lookups for a single record.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

This method only looks for records with a UP status.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

rxGetRecord

public Maybe<Record> rxGetRecord(java.util.function.Function<Record,Boolean> filter)

Lookups for a single record.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

This method only looks for records with a UP status.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

Returns:

getRecord

public void getRecord(java.util.function.Function<Record,Boolean> filter,
                      boolean includeOutOfService,
                      Handler<AsyncResult<Record>> resultHandler)

Lookups for a single record.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method may accept records with a OUT OF SERVICE status, if the includeOutOfService parameter is set to true.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

includeOutOfService - whether or not the filter accepts OUT OF SERVICE records

resultHandler - the result handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has no result.

getRecord

public void getRecord(java.util.function.Function<Record,Boolean> filter,
                      boolean includeOutOfService)

Lookups for a single record.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method may accept records with a OUT OF SERVICE status, if the includeOutOfService parameter is set to true.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

includeOutOfService - whether or not the filter accepts OUT OF SERVICE records

rxGetRecord

public Maybe<Record> rxGetRecord(java.util.function.Function<Record,Boolean> filter,
                                 boolean includeOutOfService)

Lookups for a single record.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method may accept records with a OUT OF SERVICE status, if the includeOutOfService parameter is set to true.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

includeOutOfService - whether or not the filter accepts OUT OF SERVICE records

Returns:

getRecords

public void getRecords(JsonObject filter,
                       Handler<AsyncResult<List<Record>>> resultHandler)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

Parameters:

filter - the filter - see getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>)

resultHandler - handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has an empty list as result.

getRecords

public void getRecords(JsonObject filter)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

Parameters:

filter - the filter - see getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>)

rxGetRecords

public Single<List<Record>> rxGetRecords(JsonObject filter)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

Parameters:

filter - the filter - see getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>)

Returns:

getRecords

public void getRecords(java.util.function.Function<Record,Boolean> filter,
                       Handler<AsyncResult<List<Record>>> resultHandler)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

This method only looks for records with a UP status.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

resultHandler - handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has an empty list as result.

getRecords

public void getRecords(java.util.function.Function<Record,Boolean> filter)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

This method only looks for records with a UP status.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

rxGetRecords

public Single<List<Record>> rxGetRecords(java.util.function.Function<Record,Boolean> filter)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

This method only looks for records with a UP status.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

Returns:

getRecords

public void getRecords(java.util.function.Function<Record,Boolean> filter,
                       boolean includeOutOfService,
                       Handler<AsyncResult<List<Record>>> resultHandler)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

Unlike getRecords(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<java.util.List<io.vertx.servicediscovery.Record>>>), this method may accept records with a OUT OF SERVICE status, if the includeOutOfService parameter is set to true.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

includeOutOfService - whether or not the filter accepts OUT OF SERVICE records

resultHandler - handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has an empty list as result.

getRecords

public void getRecords(java.util.function.Function<Record,Boolean> filter,
                       boolean includeOutOfService)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

Unlike getRecords(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<java.util.List<io.vertx.servicediscovery.Record>>>), this method may accept records with a OUT OF SERVICE status, if the includeOutOfService parameter is set to true.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

includeOutOfService - whether or not the filter accepts OUT OF SERVICE records

rxGetRecords

public Single<List<Record>> rxGetRecords(java.util.function.Function<Record,Boolean> filter,
                                         boolean includeOutOfService)

Lookups for a set of records. Unlike getRecord(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.servicediscovery.Record>>), this method returns all matching records.

The filter is a taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.

Unlike getRecords(io.vertx.core.json.JsonObject, io.vertx.core.Handler<io.vertx.core.AsyncResult<java.util.List<io.vertx.servicediscovery.Record>>>), this method may accept records with a OUT OF SERVICE status, if the includeOutOfService parameter is set to true.

Parameters:

filter - the filter, must not be null. To return all records, use a function accepting all records

includeOutOfService - whether or not the filter accepts OUT OF SERVICE records

Returns:

update

public void update(Record record,
                   Handler<AsyncResult<Record>> resultHandler)

Updates the given record. The record must has been published, and has it's registration id set.

Parameters:

record - the updated record

resultHandler - handler called when the lookup has been completed.

update

public void update(Record record)

Updates the given record. The record must has been published, and has it's registration id set.

Parameters:

record - the updated record

rxUpdate

public Single<Record> rxUpdate(Record record)

Updates the given record. The record must has been published, and has it's registration id set.

Parameters:

record - the updated record

Returns:

bindings

public Set<ServiceReference> bindings()

Returns:

the set of service references retrieved by this service discovery.

options

public ServiceDiscoveryOptions options()

Returns:

the discovery options. Modifying the returned object would not update the discovery service configuration. This object should be considered as read-only.

releaseServiceObject

public static void releaseServiceObject(ServiceDiscovery discovery,
                                        Object svcObject)

Release the service object retrieved using get methods from the service type interface. It searches for the reference associated with the given object and release it.

Parameters:

discovery - the service discovery

svcObject - the service object

newInstance

public static ServiceDiscovery newInstance(ServiceDiscovery arg)