Options for TAO Components

Overview

TAO can be configured in several ways. Certain components in TAO, such as the ORB Core or Object Adapter, can be tuned by users by providing value for options or environment variables to them. These options are commonly specified as (1) environment variables or (2) strings passed on the command-line. Command-line options and environment variables to control global ORB features, such as the IOR format or ORB's bootstrapping methods. They are generally passed to component initialization methods for consumption.

In addition, options in svc.conf file provide a mechanism to fine-tune internal components in TAO that are specific to particular configurations. If your program use-cases have particular characteristics, you can use the svc.conf file to customize your programs and use various optimization provided by TAO . However, a svc.conf file is not required to run TAO programs.

Programmer's Note: the internal structure for options is the traditional argc/argv vector of strings style popularized by C and Unix. By convention, an initialization method will consume, i.e., remove from the vector, any options that it recognizes.


Environment Variables

The following environment variables are supported by TAO:

Environment Variable Description
NameServiceIOR which Specifies which IOR the Naming Service is listening on.
NameServicePort which Specifies which port the Naming Service is listening on for multicast requests.
TradingServiceIOR which Specifies which IOR the Trading Service is listening on.
TradingServicePort which Specifies which port the Trading Service is listening on for multicast requests.
ImplRepoServiceIOR which Specifies the IOR of an Implementation Repository.
ImplRepoServicePort which Specifies which port the Implementation Repository is listening on for multicast requests.


Types of Options

The following components can be tuned via options:

Typically, CORBA::ORB options are set via command line parameters that are eventually passed to CORBA::ORB_init (), while the rest of the options are set via the service configurator (svc.conf) file.

CORBA::ORB

Note: -ORBGlobalCollocation flag has been merged with -ORBCollocation.

Option Description
-ORBSvcConf config file name Specifies the name of the file from which it will read dynamic service configuration directives ala ACE's Service Configurator. By default, a service configurator-based application will look for a file named "svc.conf" in the current directory.
-ORBSvcConfDirective directivestring Specifies a service configuration directive, which is passed to ACE's Service Configurator.
-ORBDaemon Specifies that the ORB should daemonize itself.
-ORBDebug Turns on the output of debugging messages within ACE's Service Configurator componentry.
-ORBDebugLevel level Control the level of debugging in the ORB. Higher number produce more output (try 10).
-ORBEndpoint endpoint Tells the ORB to listen for requests on the interface specified by endpoint. Endpoints are specified using a URL style format. An endpoint has the form:
protocol://V.v@addr1,...,W.w@addrN
where V.v and W.w are optional protcol versions for each address. An example of an IIOP endpoint is:
iiop://hostname:port
Sets of endpoints may be specified using multiple -ORBEndpoint options or by delimiting endpoints with a semi-colon (;). For example,
-ORBEndpoint iiop://localhost:9999 -ORBEndpoint uiop:///tmp/mylocalsock
is equivalent to:
-ORBEndpoint 'iiop://localhost:9999;uiop:///tmp/mylocalsock'
Notice the single quotes (') in the latter option specification. Single quotes are needed to prevent the shell from interpreting text after the semi-colon as another command to run.

If an endpoint is specified without an addr such as the following:

-ORBEndpoint uiop://
then a default endpoint will be created for the specified protocol.

This is a server side option.

-ORBHost hostname Tells the ORB to listen for requests on the interface associated with the host named hostname. This option is valid only for IIOP endpoints.
NOTE: This option has been superseded by the -ORBEndpoint option. It will not be supported in the future.
-ORBPort portspec Tells the ORB to listen for requests on the port specified by portspec. If not specified, the OS gets to choose a random empty port. This option is valid only for IIOP endpoints.
NOTE: This option has been superseded by the -ORBEndpoint option. It will not be supported in the future.
-ORBObjRefStyle which Specifies the user-visible style of object references. The range of values is IOR (default), which is the traditional nonsensical object reference, or URL, which looks more like a URL.
-ORBRcvSock receive buffer size Specify the size of the socket receive buffer as a positive, non-zero integer. If not specified, the ACE_DEFAULT_MAX_SOCKET_BUFSIZ default is used.
-ORBSndSock send buffer size Specify the size of the socket send buffer as a positive, non-zero integer. If not specified, the ACE_DEFAULT_MAX_SOCKET_BUFSIZ default is used.
-ORBNodelay boolean (0|1) Enable or disable the TCP_NODELAY option. By default, TCP_NODELAY is enabled.
-ORBNameServicePort portspec Specifies which port the Naming Service is listening on for multicast requests. By default, TAO_DEFAULT_NAME_SERVICE_REQUEST_PORT, which is 10013 is used.
-ORBNameServiceIOR ior Specifies the IOR for the Naming Service. Note, this option is deprecated since its functionality can be achieved with the standard -ORBInitRef option defined by the Interoperable Naming Service.
-ORBTradingServicePort portspec Specifies to which port the Trading Service is listening on for multicast requests. By default, TAO_DEFAULT_TRADING_SERVICE_REQUEST_PORT which is 10016 is used.
-ORBTradingServiceIOR ior Specifies the IOR for the Trading Service. Note, this option is deprecated since its functionality can be achieved with the standard -ORBInitRef option defined by the Interoperable Naming Service.
-ORBImplRepoServicePort portspec Specifies to which port the Implementation Repository is listening on for multicast requests. By default, TAO_DEFAULT_IMPLREPO_SERVER_REQUEST_PORT which is 10018 is to be used.
-ORBImplRepoServiceIOR ior Specifies the IOR for the Implementation Repository. Note, this option is deprecated since its functionality can be achieved with the standard -ORBInitRef option defined by the Interoperable Naming Service.
-ORBCollocation yes/global/per-orb/no Specifies the use of collocation object optimization. If global or yes is specified, objects in the same process will be treated as collocated. If per-orb is specified, only objects in the same ORB are treated as collocated. When no is specified, no objects are treated as collocated. Default is global.
-ORBCollocationStrategy thru_poa/direct Specifies what kind of collocated object to use. If the thru_poa strategy is used, TAO uses the collocation object implementation that respects POA's current state and policies. When using the direct strategy, method invocations on collocated objects become direct calls to servant without checking POA's status. Default is thru_poa.
-ORBPreconnect endpoint Pre-establishes a blocking connection to each listed endpoint. If a connection cannot be established the failed preconnection will be ignored and the next preconnection in the list will be processed. Successful and unsuccessful preconnections will be displayed if a debugging level greater than or equal to one is specified by using the -ORBDebugLevel option. Listing the same combination multiple times will properly establish multiple connections to that endpoint. The -ORBPreconnect option uses the same endpoint format as the -ORBEndpoint option. Specifying IIOP endpoints using a comma delimited list of host:port pairs is deprecated and will not be supported in the future.

This is a client-side option.

-ORBCDRTradeoff maxsize Control the strategy to tradeoff between copy vs. no copy marshalling of octet sequences. If an octet sequence is smaller than maxsize and the current message block contains enough space for it the octet sequence is copied instead of appended to the CDR stream. By default, ACE_DEFAULT_CDR_MEMORY_TRADEOFF is used.
-ORBSkipServiceConfigOpen Do not call the ACE_Service_Config::open method, which is necessary if the ORB is being linked dynamically via the ACE Service Configurator which is not reentrant. Default is
-ORBGIOPlite Enable a lightweight version of the GIOP protocol. This protocol removes some of the fields in the GIOP and the Request header. It only works on homogeneous environments..
-ORBDottedDecimalAddresses boolean (0|1) Use the dotted decimal notation for addresses. By default domain names are used in IORs.
-ORBInitRef ObjectId=IOR Allows specification of an arbitrary object reference for an initial service. The IOR could be in any one of the following formats : OMG IOR, URL, iioploc (including uioploc) or file. iioploc is a multiple end-point IOR understood by the string_to_object () method and used as a boot-strapping mechanism by the resolve_initial_references () method. The mappings specified through this argument override the orb-install-time defaults. The file://pathname interprets the contents of the pathname file as an object reference in any of the above formats.
-ORBDefaultInitRef IOR prefix This argument allows resolution of initial references not explicitly specified with -ORBInitRef. It requires a URL prefix that, after appending a slash '/' ('|' for UIOP pluggable protocol) and a simple object key, forms a new URL to identify an initial object reference. The URL prefix format currently supported is iioploc.
-ORBStdProfileComponents boolean (0|1) If 0 then the ORB does not generate the OMG standardized profile components, such as the ORB type and code sets. Notice that the presence of this components is optional in GIOP 1.1 The default value is controlled by a compile-time flag (check orbconf.h).
-ORBResources which Control the use of thread specific resources in the ORB. If (which = global) then the same set of resources are shared by all the threads that use that ORB. If (which = tss) then each that uses that ORB gets its own set of resources. Currently the resources are limited to the reactor.

TAO_Resource_Factory

Note: -ORBReactorLock flag has been superseded by -ORBReactorType.

Option Description
-ORBResources which Specify whether each thread uses a global (which = global) or a thread-specific (which = tss) instance for the resources it returns. The default is global . NOTE: This option controls the default value for the ORB option of the same name..
-ORBReactorType which Specify what kind of reactor does the ORB use, the options are:
whichReactor
select_mtUse the ACE_Select_Reactor with the usual locking mechanism for this platform
select_stUse the ACE_Select_Reactor with null locks
flUse the ACE_FlReactor only available if ACE was compiled with support for the FL toolkit
-ORBReactorMaskSignals 0/1 ACE select reactors mask signals during upcalls to the event handlers. This is only useful if the application is going to trap those signals and handle them in any way. Disabling the mask can improve performance by reducing the number of kernel level locks.
wfmo Use the ACE_WFMO_Reactor only available on Win32 platforms.
msg_wfmoUse the ACE_Msg_WFMO_Reactor only available on Win32 platforms.
tpUse the ACE_TP_Reactor, a select based thread-pool reactor.
The default is select_mt
-ORBProtocolFactory factory Specify which pluggable protocol factory to load. By default, the factories for the IIOP and UIOP protocols (IIOP_Factory and UIOP_Factory, respectively) are loaded.

For example, if some protocol called Foo whose factory was called Foo_Factory was available, then it could be loaded into TAO by specifying -ORBProtocolFactory Foo_Factory in the service configurator file. The Foo pluggable protocol would then be available for use.

-ORBInputCDRAllocator which Specify whether the ORB uses locked (which = thread) or lock-free (which = null) allocators for the incoming CDR buffers. Though null should give the optimal performance; we made the default thread. TAO optimizations for octet sequences will not work in all cases when if the allocator does not have locks (for example if the octet sequences are part of a return value. Using locked allocators also allows the users to take advantage of the TAO octet sequence extensions to preserve the buffer after the upcall.
-ORBConnectionCachingStrategy type Specify the strategy to use for caching and purging connections. By default, TAO_CONNECTION_CACHING_STRATEGY is used which has been set to Least Recently Used (LRU). For example, for choosing the First In First Out option just add -ORBConnectionCachingStrategy fifo to the service configurator file.
-ORBPurgePercentage percent Specify the number of connections to remove form the connection cache during auto-purging. By default, TAO_PURGE_PERCENT is used which has been set to 20. For example, for choosing 75% just add -ORBPurgePercentage 75 to the service configurator file.
-ORBSchedPolicy policy Specify the scheduling policy used for the priority mapping computations. Priority mappings map the CORBA priority range (from 0 to 32767) into the native OS priority range, but in some operating systems the range depends on the scheduling policy used. Using this option the user can set the scheduling policy, valid values as SCHED_OTHER, SCHED_FIFO and SCHED_RR, notice that in some operating systems some of the scheduling policies require super user privileges.
-ORBPriorityMapping mapping_type Select the priority mapping to use. The default resource factory provide two priority mapping implementations, linear selects a linear mapping between the CORBA range of priorities and the native range of priorities for the selected scheduling policy. The direct mapping maps the first n CORBA priorities to the range of native priorities, where n is the number of native priorities. In all the operating systems where TAO is supported the range of CORBA priorities is larger than the native set.

TAO_Default_Server_Strategy_Factory

Note: -ORBDemuxStrategy flag has been changed to -ORBSystemidPolicyDemuxStrategy and -ORBUseridPolicyDemuxStrategy.

Note: -ORBTableSize flag has been changed to -ORBActiveObjectMapSize.

Option Description
-ORBConcurrency which Specify which concurrency strategy to use. Range of values is reactive for a purely Reactor-driven concurrency strategy or thread-per-connection for creating a new thread to service each connection. The default is reactive.

TAO also supports the thread-pool concurrency model but this is implemented by the user, creating multiple threads that call ORB::run() and using the -ORBReactorType tp option.

-ORBThreadPerConnectionTimeout milliseconds In many platforms it is impossible to interrupt the server threads created by the thread-per-connection model. This is because these threads are blocked in read() operations (and not in select()). As a workaround, the server threads periodically poll the ORB to find out if they should shutdown. This option controls the period of the polling, expressed in milliseconds. Applications that do not shutdown, or that can otherwise ensure that no server threads will be running at shutdown (for example if all the clients terminate before the server) can disable the polling using the magic value INFINITE.

If the option is not provided then the ORB uses the compile time flag TAO_DEFAULT_THREAD_PER_CONNECTION_TIMEOUT, this flag also expresses the time in milliseconds (as a string constant) and the magic value "INFINITE" can be used to disable polling entirely. This yields a slight performance improvement (around 1%).

-ORBActiveObjectMapSize active object map size Specify the size of the active object map. If not specified, the default value is 64.
-ORBUseridPolicyDemuxStrategy user id policy based demultiplexing strategy Specify the demultiplexing lookup strategy to be used with the user id policy. The demultiplexing strategy can be one of dynamic or linear. This option defaults to use the dynamic strategy.
-ORBSystemidPolicyDemuxStrategy system id policy based demultiplexing strategy Specify the demultiplexing lookup strategy to be used with the system id policy. The demultiplexing strategy can be one of dynamic, linear, or active. This option defaults to use the active strategy.
-ORBUniqueidPolicyReverseDemuxStrategy unique id policy based reverse demultiplexing strategy Specify the reverse demultiplexing lookup strategy to be used with the unique id policy. The reverse demultiplexing strategy can be one of dynamic or linear. This option defaults to use the dynamic strategy.
-ORBAllowReactivationOfSystemids allows reactivation of system ids Specify whether system ids can be reactivated, i.e., once an id that was generated by the system has be deactivated, will the user reactivate a new servant using the old id. If the user is not going to use this feature, the IORs can be shortened, an extra comparison in the critical upcall path removed, and some memory on the server side can be saved. The ORBAllowReactivationOfSystemids can be 0 or 1. This option defaults to 1.
-ORBActiveHintInIds adds an active hint in ids Specify whether an active hint should be added to ids. With active hints, ids can be found quickly. However, they lead to larger IORs. Note that this option is disregarded -ORBAllowReactivationOfSystemids is set to 0. The -ORBActiveHintInIds can be 0 or 1. This option defaults to 1.
-ORBPoaMapSize poa map size Specify the size of the poa map. If not specified, the default value is 24.
-ORBPersiententidPolicyDemuxStrategy persistent id policy based demultiplexing strategy Specify the demultiplexing lookup strategy to be used with the persistent id policy. The demultiplexing strategy can be one of dynamic or linear. This option defaults to use the dynamic strategy.
-ORBTransientidPolicyDemuxStrategy transient id policy based demultiplexing strategy Specify the demultiplexing lookup strategy to be used with the transient id policy. The demultiplexing strategy can be one of dynamic, linear, or active. This option defaults to use the active strategy.
-ORBActiveHintInPOANames adds an active hint in poa names Specify whether an active hint should be added to poa names. With active hints, poa names can be found quickly. However, they lead to larger IORs. The -ORBActiveHintInPOANames can be 0 or 1. This option defaults to 1.
-ORBThreadFlags thread flags Specify the flags used for thread creation. Flags can be any logical-OR combination of THR_DETACHED, THR_BOUND, THR_NEW_LWP, THE_SUSPENDED. The default is THR_BOUND | THR_DETACHED .
-ORBPOALock lock type Specify the type of lock to be used for POA accesses. Possible values for lock type are thread, which specifies that an inter-thread mutex is used to guarantee exclusive access, and null, which specifies that no locking be performed. The default is thread.
-ORBConnectorLock lock type This option has been moved to the client strategy factory.

TAO_Default_Client_Strategy_Factory

Option Description
-ORBProfileLock which Specify the kind of synchronization primitive for the Profiles. Default is thread, which means that a regular thread mutex is used. The second option is null, which means a null lock is used. This makes sense in case of optimizations and is allowed when no forwarding is used or only a single threaded client.
-ORBClientConnectionHandler MT / ST / RW ST means use the single-threaded client connection handler, i.e., the leader follower model will not be used. However, ST does support nested upcalls and handling of new requests while waiting for the reply from a server.

MT means use the multi-threaded client connection handler which uses the leader follower model. This model allows the use of multiple threads with a single Reactor.

RW selects a strategy that simply blocks in recv() when waiting for a response from the server instead of waiting in the Reactor. The RW strategy only works when the application does not have to worry about new request showing up when waiting for a response. Therefore, this strategy is appropriate only for "pure" clients. Note that applications with nested upcalls are not "pure" clients. Also note that this strategy will only effect two way calls, since there is no waiting for one way calls. This strategy can also be used in an application that is both a client and a server if the server side is handled by a separate thread and the client threads are "pure" clients.

Default for this option is MT.

-ORBTransportMuxStrategy EXCLUSIVE / MUXED EXCLUSIVE means that the Transport does not multiplex requests on a connection. At a time, there can be only one request pending on a connection.

MUXED means that Transport multiplexes more than one request at the same time on a connection. This is very important for getting the Asynchronous Method Invocation model to work. This is not implemented yet.

Default for this option is EXCLUSIVE.

-ORBConnectorLock lock type Specify the type of lock to be used by the connector. Possible values for lock type are thread, which specifies that an inter-thread mutex is used to guarantee exclusive access, and null, which specifies that no locking be performed. The default is thread.


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