Description This function initiates execution of an embedded script in the active document of all active remote nodes in a connections array. There is also an optional parameter indicating the maximum wait time for the embedded script to complete before continuing execution of the master script.
Syntax count = IPCExecEmbeddedScript( connections(), scriptName, maxwait )
Parameters count (Long) Returned number of successfully initiated embedded script executions. This does not indicate the number of successfully completed embedded script executions.
connections() As T_IPCINSTANCE An array of T_IPCINSTANCE structures, with each structure defining the connection information for a remote node.
scriptName As String The name of the embedded script in the active FRED document of the remote nodes which should be executed.
maxWait As String This argument indicates the maximum wait time for the embedded script to finish executing on all remote nodes before continuing with the master script execution. If the embedded scripts on the remote nodes finish execution before this maxWait time, the master script will automatically continue. Time units may be indicated using the following conventions: s=seconds, m=minutes, h=hours, d=days, w=weeks, mo=months (ex. "10s" = 10 seconds). In the absence of a time unit designation, seconds will be assumed.
Example The example below demonstrates a typical distributed computing calculation where a FRED file (the one being run by the master) is pushed to the remote nodes, an embedded script within the FRED file is executed and FRED grid data (FGD) output files are pulled back to the master node for accumulation into a final result. Several helper functions are included to keep the code modular.
Sub Main
'This script demonstrates how to use the Distributed Computing component of FRED in order 'to send an analysis out to "remote" nodes on a Windows network, retrieve the results from 'each remote node and then recombine them on the "master" computer.
'Master document preparation ARNDeleteAllNodes() PrefsSetARNRetainCount( -1 ) ClearOutputWindow()
'Remove any FGD files in the current directory on the master node Dim nDel As Long nDel = KillFgd( GetDocDir() ) Print "" Print "Removed " & nDel & " FGD files from the current directory."
'Load the connections() array from a CSV file Dim nRemoteLoad As Long Dim connections() As T_IPCINSTANCE Dim configFile As String, configLocation As String configLocation = GetDocDir() & "\" configFile = "DCTestBed_Connections.csv" nRemoteLoad = IPCLoadConfigFile( connections(), configLocation & configFile )
'Connect to the remote nodes Dim nConnect As Long nConnect = IPCConnect( connections() )
'Query the status of the remote nodes (info printed to output window). Dim nStatus As Long nStatus = IPCQueryStatus( connections(), "" )
'Push the FRED file to the remote nodes (file is the same as the file being run on master) Dim nPush As Long, nDisconnect As Long Dim fName As String fName = name 'returns the name (with FRD extension) of the FRED document associated with this script nPush = IPCPushFile( connections(), fName, "", "overwrite copy" ) If nPush < 1 Then Print "No files were successfully pushed to the remotes. Terminating connections and stopping the master script." nDisconnect = IPCTerminate( connections(), "sterilize", "" ) End End If
'Load the model into the remote instances and execute an embedded script Dim scriptName As String, nScript As Long, nLoad As Long scriptName = "Remote Node Script" nLoad = IPCLoadModel( connections(), fName, "1d" ) nScript = IPCExecEmbeddedScript( connections(), scriptName, "1d" )
'Have the remote instances push FGD files back to the master node. Embedded script was 'written to produce FGD files. Dim nPull As Long Dim pulledFiles() As String nPull = IPCPullFile( connections(), "*.fgd", configLocation, "move", pulledFiles() )
'Print a report of the files that were pulled from the remotes Dim curFile As String Print "" Print "The following files were successfully pulled from the remote nodes:" For Each curFile In pulledFiles() Print Chr(9) & curFile Next
'Terminate the connection to remotes. nDisconnect = IPCTerminate( connections(), "sterilize", "" )
'Load FGD files from remotes into master FRED document and sum them together 'to form a final result. Dim nFgd As Long, finalArn As Long If nPull > 0 Then nFgd = LoadFgd( pulledFiles() ) Print "" Print "Loaded " & nFgd & " FGD files into ARNs." finalArn = CompositeAllARN( ) Print "Final result stored in ARN " & finalArn Else Print "No files were pulled from remote nodes. No final result generated." End If
Print "" Print "Distributed calculation completed."
End Sub Function LoadFgd( ByVal in_files() As String ) As Long
'This helper function loops over an array of strings that 'specify the full file path to a set of FGD files and then 'loads them into the FRED document as ARN. 'INPUTS: ' in_files() = string defining the directory to be searched 'OUTPUTS: ' returns the number of ARN that were created
Dim cFile As String, splitStrs() As String Dim nF As Long
nF = 0 For Each cFile In in_files() splitStrs = Split(cFile, "\") 'split the full file path name by "\" splitStrs = Split( splitStrs(UBound(splitStrs)), ".") 'split the file name by "." to remove the file extension ARNCreateFromFile( cFile, splitStrs(0) ) nF += 1 Next
Return nF
End Function
Function CompositeAllARN( ) As Long
'This helper function loops over the Analysis Results folder 'and summs all of the ARN into a composite result. 'INPUTS: ' None 'OUTPUTS: ' Returns the node number of the composite ARN
'What node number is the last ARN on the tree at? Dim nArn As Long nArn = ARNGetMaxNodeNum()
'Make a copy of the zeroth ARN. This will become the 'final composite result node. Dim compArn As Long compArn = ARNCreateCopy( 0, "Composite Result" )
'Start looping over the other ARN starting at index 1 Dim curArn As Long For curArn = 1 To nArn ARNLinearCombination( 1, compArn, 1, curArn ) Next
Return compArn
End Function
Function KillFgd( ByVal in_dir As String ) As Long
'This helper function scans a directory for FGD files 'and deletes them 'INPUTS: ' in_dir = string defining the directory to be searched 'OUTPUTS: ' returns the number of FGD files that were deleted
'Change to the search directory ChDir( in_dir )
Dim nF As Long Dim cFile As String nF = 0 cFile = Dir$("*.fgd") While cFile <> "" Kill( cFile ) nF += 1 cFile = Dir$() Wend
Return nF
End Function
The example code above produces the following content in the FRED output window: Removed 0 FGD files from the current directory.
[MASTER]IPCLoadConfigFile: 3 of 3 connections read from 'C:\temp\DCTestBed_Connections.csv'
index active speed host status 1 true 100 computer1 --- 2 true 100 computer2 --- 3 true 100 computer3 ---
[MASTER]IPCConnect: 3 of 3 Remote FRED instances connected and running
index host result message 1 computer1 connected --- 2 computer2 connected --- 3 computer3 connected ---
[MASTER]IPCQueryStatus: 3 connections queried
index host message 1 computer1 idle 2 computer2 idle 3 computer3 idle
[MASTER]IPCPushFile: 3 files pushed from 'dctestbed.frd' to ''
index host src/xfer/dest message 1 computer1 1/1/1 finished 2 computer2 1/1/1 finished 3 computer3 1/1/1 finished
[MASTER]IPCLoadModel: 3 of 3 queued for loading file 'DCTestBed.frd'
[MASTER]IPCExecEmbeddedScript: 3 of 3 queued for execution 'Remote Node Script' (static load balancing)
[MASTER]IPCPullFile: 3 files pulled from '*.fgd' to 'C:\temp\'
index host src/xfer/dest message 1 computer1 1/1/1 finished 2 computer2 1/1/1 finished 3 computer3 1/1/1 finished
The following files were successfully pulled from the remote nodes: C:\temp\Color Image Result_computer1_lh_20160117135803_00000004.fgd C:\temp\Color Image Result_computer2_lh_20160117135803_00000009.fgd C:\temp\Color Image Result_computer3_lh_20160117135804_00000001.fgd
[MASTER]IPCTerminate: 3 of 3 Remote FRED instance terminations initiated
index host message 1 computer1 terminate - initiated 2 computer2 terminate - initiated 3 computer3 terminate - initiated
Loaded 3 FGD files into ARNs. Final result stored in ARN 3
Distributed calculation completed.
See Also Distributed Computing Script Commands
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