[omniORB] Optimizing the roundtrip-time of function calls?

[Oliver Frick]

Hello Duncan.

Am 28.04.2009 um 15:54 schrieb Duncan Grisby:

> On Saturday 25 April, Oliver Frick wrote:
>
>> How can I optimize a function call's roundtrip time?
>> I have measured the up-call and return time of a corba
>> call between two processes on the same host.
>> The result is always that the up-call time is much smaller
>> than the return time. The ratio is typically 1/5,
>> sometimes 1/100 or more.
>> The function is rather simple, it has no arguments
>> (or two longs; I added them for testing) and always two
>> longs in a returned struct.
>>
>> If the ORB is able to up-call the other object in, say
>> 150 usec, why does it need 1.5 msec to return? Can I
>> reduce the return time by configuring omniorb?
>
> How are you measuring it?  I would not expect that, and have never  
> seen
> anything to suggest that return handling was slower than incoming call
> handling.

I take time-stamps from the hires system clock immediately before and
after the call on the client side and during the call on the server  
side.
(hires_clock() is a wrapper to platform specific high resolution clocks,
e.g. PerformanceCounter under Windows).

client:
hires_clock_t a = hires_clock();
obj->Foo();
hires_clock_t b = hires_clock();

server:
void Server:: Foo()
{
     hires_clock_t m = hires_clock();
}

Since it is the same clock (both processes run on the same host)
the time-stamps are compatible:
(m - a) = (b - m) / R
with R between 4 and 10, sometimes higher.

I get similar results on Windows XP and Mac OS 10.5.


> How are you configuring omniORB?  Are you using bidirectional GIOP?

I've tested both. Activating in a bidir POA and in the root POA:
same result. I have also variated the oneCallPerConnection parameter.

Here is the config output on Mac OS 10.5.6:

omniORB: Version: 4.1.3
omniORB: Distribution date: Tue Sep 23 10:43:28 BST 2008 dgrisby
omniORB: My addresses are:
omniORB: 127.0.0.1
omniORB: ::1
omniORB: <my LAN ip>
omniORB: <my WAN ip>
omniORB: Maximum supported GIOP version is 1.2
omniORB: Native char code sets: UTF-8 ISO-8859-1.
omniORB: Transmission char code sets: UTF-8(1.2) UTF-8(1.1)  
ISO-8859-1(1.2) ISO-8859-1(1.1) ISO-8859-1(1.0).
omniORB: Native wide char code sets: UTF-16.
omniORB: Transmission wide char code sets: UTF-16(1.2).
omniORB: Initialising omniDynamic library.
omniORB: Current configuration is as follows:
omniORB:   DefaultInitRef (file) =
omniORB:   DefaultInitRef (args) =
omniORB:   abortOnInternalError = 0
omniORB:   abortOnNativeException = 0
omniORB:   acceptBiDirectionalGIOP = 1
omniORB:   acceptMisalignedTcIndirections = 0
omniORB:   bootstrapAgentHostname =
omniORB:   bootstrapAgentPort = 900
omniORB:   clientCallTimeOutPeriod = 0
omniORB:   clientConnectTimeOutPeriod = 0
omniORB:   clientTransportRule = * unix,tcp,ssl,bidir
omniORB:   configFile = <path deleted>
omniORB:   connectionWatchImmediate = 0
omniORB:   connectionWatchPeriod = 50000
omniORB:   copyValuesInLocalCalls = 1
omniORB:   diiThrowsSysExceptions = 0
omniORB:   dumpConfiguration = 0
omniORB:   endPoint = giop:tcp::2809
omniORB:   endPointPublish = addr
omniORB:   giopMaxMsgSize = 2097152
omniORB:   giopTargetAddressMode = KeyAddr
omniORB:   id = omniORB4
omniORB:   idleThreadTimeout = 10
omniORB:   immediateAddressSwitch = 0
omniORB:   inConScanPeriod = 180
omniORB:   lcdMode = 0
omniORB:   maxGIOPConnectionPerServer = 5
omniORB:   maxGIOPVersion = 1.2
omniORB:   maxInterleavedCallsPerConnection = 5
omniORB:   maxServerThreadPerConnection = 100
omniORB:   maxServerThreadPoolSize = 100
omniORB:   maxSocketRecv = 2147483647
omniORB:   maxSocketSend = 2147483647
omniORB:   nativeCharCodeSet = ISO-8859-1
omniORB:   nativeWCharCodeSet = UTF-16
omniORB:   objectTableSize = 0
omniORB:   offerBiDirectionalGIOP = 0
omniORB:   oneCallPerConnection = 0
omniORB:   outConScanPeriod = 120
omniORB:   poaHoldRequestTimeout = 0
omniORB:   poaUniquePersistentSystemIds = 1
omniORB:   principal = [Null]
omniORB:   resetTimeOutOnRetries = 0
omniORB:   scanGranularity = 5
omniORB:   serverCallTimeOutPeriod = 0
omniORB:   serverTransportRule = * unix,tcp,ssl,bidir
omniORB:   socketSendBuffer = -1
omniORB:   strictIIOP = 1
omniORB:   supportBootstrapAgent = 0
omniORB:   supportCurrent = 1
omniORB:   supportPerThreadTimeOut = 0
omniORB:   tcAliasExpand = 0
omniORB:   threadPerConnectionLowerLimit = 9000
omniORB:   threadPerConnectionPolicy = 1
omniORB:   threadPerConnectionUpperLimit = 10000
omniORB:   threadPoolWatchConnection = 1
omniORB:   traceExceptions = 1
omniORB:   traceFile = [stderr]
omniORB:   traceInvocationReturns = 0
omniORB:   traceInvocations = 1
omniORB:   traceLevel = 25
omniORB:   traceThreadId = 0
omniORB:   traceTime = 0
omniORB:   unixTransportDirectory = /tmp/omni-%u
omniORB:   unixTransportPermission =  777
omniORB:   useTypeCodeIndirections = 1
omniORB:   validateUTF8 = 0
omniORB:   verifyObjectExistsAndType = 1