Changes of Simple Parallel Exec from #2 to #3

Changed lines at line 11
- SSH (public key authorisation)
1.1 Features & Configurability
- list of computer names or IPs
- commandline pattern with space holders for variables
- validation (return value and/or existance of a file)
- list with all parameter settings, which should be processed
- simple task assignment: if a computer is ready with one task give him the next from the list
- error detection (see next section)
- in case of an error while executing one task give it to the next machine and mark that machine as dead
- collecting rules: a) stdout processing (plain concat ; blockwise with parameters) b) file processing (plain concat, with parameters)
1.1 Error detection
The folling errors need to be detected:
- error while connection/authentication
- machine dead (for whatever reason)
- connection broken
- programm terminated without success
1 Implementation Details
1.1 Configuation and Files
- Cluster file: list of computers, one per line
- Parameter file: csv file, cells seperated with |, parameter names in the headline and every following line contains one parameter set. All lines have to have the same amount of cells like the headline!
- Commandline pattern: a perl syntax String with parameter Variables for the parameters
- Validation function: gets the parameters set and the result of the programm and returns success or not
- Collection function: gets the parameters set and the result of the programm and can do whatever with it (usually print it in a file)
1.1 Error detection
Remote shell command (ssh) termination code:
- 0 => Success: The program has been executed with success!
- otherswise => Failure: Can have the following reasons: connection failed, programm not found or terminated without success.
To check the connection and authentication run:
{code:shell}ssh host echo{code}
- return 0 (success): Connection is OK and machine lives. The program was either not found or it didn't terminate with 0. Either case we assume that this parameter set is somehow bad and skip it. 
- otherwise mark this machine as dead and reschedule the parameter set.
- SSH (public key authentication)
- permanent network connection
1.1 Features & Configurability
- one master computer
- list of slave computers (names or IPs)
- commandline pattern with space holders for variables
- validation (return value and/or existance of a file)
- list with all parameter settings, which should be processed
- simple task assignment: if a computer is ready with one task give him the next from the list
- error detection (see next section)
- in case of an error while executing one task give it to the next machine and mark that machine as dead
- collecting rules: a) stdout processing (plain concat ; blockwise with parameters) b) file processing (plain concat, with parameters)
1.1 Error detection
The folling errors need to be detected:
- error while connection/authentication
- machine dead (for whatever reason)
- connection broken
- programm terminated without success
1 Implementation Details
1.1 Configuation and Files
- Cluster file: list of computers, one per line
- Parameter file: csv file, cells seperated with |, parameter names in the headline and every following line contains one parameter set. All lines have to have the same amount of cells like the headline!
- Commandline pattern: a perl syntax String with parameter Variables for the parameters
- Validation function: gets the parameters set and the result of the programm and returns success or not
- Collection function: gets the parameters set and the result of the programm and can do whatever with it (usually print it in a file)
1.1 Error detection
Remote shell command (ssh) termination code:
- 0 => Success: The program has been executed with success!
- otherswise => Failure: Can have the following reasons: connection failed, programm not found or terminated without success.
To check the connection and authentication run:
{code:shell}ssh host echo{code}
- return 0 (success): Connection is OK and machine lives. The program was either not found or it didn't terminate with 0. Either case we assume that this parameter set is somehow bad and skip it. 
- otherwise mark this machine as dead and reschedule the parameter set.
One case that is not covered by the above procedure is if the connection breaks. Then the ssh command is just not terminating. 
Solution: asyncron periodic ping