Package com.google.appengine.tools.development

Class Modules

java.lang.Object

com.google.appengine.tools.development.Modules

All Implemented Interfaces:

ModulesController, ModulesFilterHelper

Direct Known Subclasses:

Modules, ModulesEE8

public class Modules
extends Object
implements ModulesController, ModulesFilterHelper

Manager for DevAppServer servers.

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.appengine.tools.development.ModulesController

ModulesController.ModuleState

Field Summary

Fields inherited from interface com.google.appengine.tools.development.ModulesController

MODULES_CONTROLLER_ATTRIBUTE_KEY

Constructor Summary

Constructors

Constructor	Description
Modules(List<Module> modules)

Method Summary

Modifier and Type	Method	Description
boolean	acquireServingPermit(String moduleName, int instanceNumber, boolean allowQueueOnBackends)	This method guards access to module instances to limit the number of concurrent requests.
boolean	checkInstanceExists(String moduleName, int instance)	Verifies if a specific module instance is configured.
boolean	checkInstanceStopped(String moduleName, int instance)	Verifies if a specific existing module or backend instance is stopped.
boolean	checkModuleExists(String moduleName)	Verifies if a specific module or backend is configured.
boolean	checkModuleStopped(String serverName)	Verifies if a specific existing module or backend is stopped.
void	configure(Map<String,Object> containerConfigProperties)
void	createConnections()
static Modules	createModules(ApplicationConfigurationManager applicationConfigurationManager, String serverInfo, File externalResourceDir, String address, DevAppServer devAppServer)
boolean	expectsGeneratedStartRequests(String moduleName, int instance)	Returns true if internally generated "/_ah/start" requests are provided for the specified module or backend instance.
int	getAndReserveFreeInstance(String moduleName)	Acquires a serving permit for an instance with available capacity and returns the instance id.
String	getDefaultVersion(String moduleName)	Returns the default version for a named module.
String	getHostname(String moduleName, String version, int instance)	Returns the host name of the requested module version instance.
static Modules	getInstance()
LocalServerEnvironment	getLocalServerEnvironment()
Module	getMainModule()
Module	getModule(String moduleName)
Iterable<String>	getModuleNames()	Returns all the known module names.
ModulesController.ModuleState	getModuleState(String moduleName)	Returns the current state of this module.
int	getNumInstances(String moduleName, String version)	Returns the number of instances for the requested module version.
int	getPort(String moduleName, int instance)	Returns the port for the specified module of backend instance.
String	getScalingType(String moduleName)	Returns the type of scaling in use for this module.
Iterable<String>	getVersions(String moduleName)	Returns all known versions of the requested module.
boolean	isLoadBalancingInstance(String moduleName, int instance)	Returns true if the specified module or backend instance is a load balancing instance which will forward requests to an available instance.
void	returnServingPermit(String moduleName, int instance)	Returns a serving permit after a request has completed.
void	setApiProxyDelegate(ApiProxy.Delegate<?> apiProxyDelegate)
void	setNumInstances(String moduleName, String version, int numInstances)	Sets the number of instances for the requested module version.
void	shutdown()
void	startModule(String moduleName, String version)	Starts the requested module version.
void	startup()
void	stopModule(String moduleName, String version)	Stops the requested module version.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Modules

public Modules(List<Module> modules)

Method Details

createModules

public static Modules createModules(ApplicationConfigurationManager applicationConfigurationManager,
 String serverInfo,
 File externalResourceDir,
 String address,
 DevAppServer devAppServer)

getInstance

public static Modules getInstance()

shutdown

public void shutdown()
              throws Exception

Throws:

Exception

configure

public void configure(Map<String,Object> containerConfigProperties)
               throws Exception

Throws:

Exception

setApiProxyDelegate

public void setApiProxyDelegate(ApiProxy.Delegate<?> apiProxyDelegate)

createConnections

public void createConnections()
                       throws Exception

Throws:

Exception

startup

public void startup()
             throws Exception

Throws:

Exception

getMainModule

public Module getMainModule()

getLocalServerEnvironment

public LocalServerEnvironment getLocalServerEnvironment()

getModule

public Module getModule(String moduleName)

getModuleNames

public Iterable<String> getModuleNames()

Description copied from interface: ModulesController

Returns all the known module names.

Specified by:

getModuleNames in interface ModulesController

getVersions

public Iterable<String> getVersions(String moduleName)
                             throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Returns all known versions of the requested module.

Specified by:

getVersions in interface ModulesController

Throws:

ApiProxy.ApplicationException - with error code .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not configured

getDefaultVersion

public String getDefaultVersion(String moduleName)
                         throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Returns the default version for a named module.

Specified by:

getDefaultVersion in interface ModulesController

Throws:

ApiProxy.ApplicationException - with error code .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not configured

getNumInstances

public int getNumInstances(String moduleName,
 String version)
                    throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Returns the number of instances for the requested module version.

Specified by:

getNumInstances in interface ModulesController

Throws:

ApiProxy.ApplicationException - with error code .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not configured and .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_VERSION_VALUE if the requested version is not configured.

setNumInstances

public void setNumInstances(String moduleName,
 String version,
 int numInstances)
                     throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Sets the number of instances for the requested module version.

Specified by:

setNumInstances in interface ModulesController

Throws:

ApiProxy.ApplicationException - with error code .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not configured and .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_VERSION_VALUE if the requested version is not configured for setting instances .ErrorCode#INVALID_INSTANCES if numInstances is not a legal value.

getHostname

public String getHostname(String moduleName,
 String version,
 int instance)
                   throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Returns the host name of the requested module version instance.

Specified by:

getHostname in interface ModulesController

Parameters:

moduleName - the moduleName whose host we return.

version - the version whose host we return.

instance - the instance whose host we return or

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.tools.development.LocalEnvironment#MAIN_INSTANCE

Throws:

ApiProxy.ApplicationException - with error code .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not configured and .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_VERSION_VALUE if the requested version is not configured and .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_INSTANCES_VALUE if the requested instance is not configured.

getModuleState

public ModulesController.ModuleState getModuleState(String moduleName)
                                             throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Returns the current state of this module.

Specified by:

getModuleState in interface ModulesController

Throws:

ApiProxy.ApplicationException - with error code .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not configured

getScalingType

public String getScalingType(String moduleName)
                      throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Returns the type of scaling in use for this module.

Specified by:

getScalingType in interface ModulesController

Throws:

ApiProxy.ApplicationException - with error code .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not configured

startModule

public void startModule(String moduleName,
 String version)
                 throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Starts the requested module version.

Specified by:

startModule in interface ModulesController

Throws:

ApiProxy.ApplicationException - .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not a configured manual scaling module and .ErrorCode#INVALID_VERSION_VALUE if the requested version is not configured or is not a manual scaling module and .ModulesServiceError.ErrorCode#UNEXPECTED_STATE if the module instance is not stopped and ready to be started.

stopModule

public void stopModule(String moduleName,
 String version)
                throws ApiProxy.ApplicationException

Description copied from interface: ModulesController

Stops the requested module version.

Specified by:

stopModule in interface ModulesController

Throws:

ApiProxy.ApplicationException - .modules.ModulesServicePb.ModulesServiceError.ErrorCode#INVALID_MODULE_VALUE if the requested module is not a configured manual scaling module and .ModulesServiceError.ErrorCode#INVALID_VERSION_VALUE if the requested version is not configured or is not a manual scaling module and .ErrorCode#UNEXPECTED_STATE if the module instance is not running and ready to be stopped.

acquireServingPermit

public boolean acquireServingPermit(String moduleName,
 int instanceNumber,
 boolean allowQueueOnBackends)

Description copied from interface: ModulesFilterHelper

This method guards access to module instances to limit the number of concurrent requests. Each request running on a module instance must acquire a serving permit. If no permits are available a 500 response should be sent.

Specified by:

acquireServingPermit in interface ModulesFilterHelper

Parameters:

moduleName - The module or backend for which to acquire a permit.

instanceNumber - The server instance for which to acquire a permit.

allowQueueOnBackends - If set to false the method will return instantly, if set to true (and the specified server allows pending queues) this method can block for up to 10 s waiting for a serving permit to become available.

Returns:

true if a permit was acquired, false otherwise

getAndReserveFreeInstance

public int getAndReserveFreeInstance(String moduleName)

Description copied from interface: ModulesFilterHelper

Acquires a serving permit for an instance with available capacity and returns the instance id. If no instance has capacity this returns -1.

For backends which support queued requests this may block for a limited time waiting for an instance to become available (see

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AbstractBackendServers#getAndReserveFreeInstance

for details). Supported for modules that support load balancing (currently ManualModule). The client can check with ModulesFilterHelper.isLoadBalancingInstance(String, int).

Specified by:

getAndReserveFreeInstance in interface ModulesFilterHelper

Parameters:

moduleName - Name of the requested module or backend.

Returns:

the instance id of an available server instance, or -1 if no instance is available.

returnServingPermit

public void returnServingPermit(String moduleName,
 int instance)

Description copied from interface: ModulesFilterHelper

Returns a serving permit after a request has completed.

Specified by:

returnServingPermit in interface ModulesFilterHelper

Parameters:

moduleName - The server name

instance - The server instance

checkInstanceExists

public boolean checkInstanceExists(String moduleName,
 int instance)

Description copied from interface: ModulesFilterHelper

Verifies if a specific module instance is configured.

Specified by:

checkInstanceExists in interface ModulesFilterHelper

Parameters:

moduleName - The module or backend name

instance - The module instance

Returns:

true if the module instance is configured and false otherwise.

checkModuleExists

public boolean checkModuleExists(String moduleName)

Description copied from interface: ModulesFilterHelper

Verifies if a specific module or backend is configured.

Specified by:

checkModuleExists in interface ModulesFilterHelper

Parameters:

moduleName - The module or backend name

Returns:

true if the module is configured and false otherwise.

checkModuleStopped

public boolean checkModuleStopped(String serverName)

Description copied from interface: ModulesFilterHelper

Verifies if a specific existing module or backend is stopped.

Specified by:

checkModuleStopped in interface ModulesFilterHelper

Parameters:

serverName - The module or backend name

Returns:

true if the module is stopped, false otherwise.

checkInstanceStopped

public boolean checkInstanceStopped(String moduleName,
 int instance)

Description copied from interface: ModulesFilterHelper

Verifies if a specific existing module or backend instance is stopped.

Specified by:

checkInstanceStopped in interface ModulesFilterHelper

Parameters:

moduleName - The module or backedn name

instance - The module instance

Returns:

true if the module instance is stopped and false otherwise.

isLoadBalancingInstance

public boolean isLoadBalancingInstance(String moduleName,
 int instance)

Description copied from interface: ModulesFilterHelper

Returns true if the specified module or backend instance is a load balancing instance which will forward requests to an available instance.

Specified by:

isLoadBalancingInstance in interface ModulesFilterHelper

Parameters:

moduleName - The module or backend name

instance - The requested instance which can be -1.

expectsGeneratedStartRequests

public boolean expectsGeneratedStartRequests(String moduleName,
 int instance)

Description copied from interface: ModulesFilterHelper

Returns true if internally generated "/_ah/start" requests are provided for the specified module or backend instance.

Http "/_ah/start" requests for instances where this returns true are presumed to be internally generated and receive special treatment by DevAppServerModulesFilter. Requests to "/_ah/start" for other instances are treated as normal requests.

Specified by:

expectsGeneratedStartRequests in interface ModulesFilterHelper

Parameters:

moduleName - The module or backend name

instance - The module instance which can be -1.

getPort

public int getPort(String moduleName,
 int instance)

Description copied from interface: ModulesFilterHelper

Returns the port for the specified module of backend instance.

Specified by:

getPort in interface ModulesFilterHelper

Parameters:

moduleName - The module or backend name

instance - The requested instance which can be -1.