Experiment Names

The default name for a new experiment is test.1.er . The suffix .er is mandatory: if you give a name that does not have it, an error message is displayed and the name is not accepted.

If you choose a name with the format experiment.n.er, where n is a positive integer, the Collector automatically increments n by one in the names of subsequent experiments—for example, mytest.1.er is followed by mytest.2.er, mytest.3.er , and so on. The Collector also increments n if the experiment already exists, and continues to increment n until it finds an experiment name that is not in use. If the experiment name does not contain n and the experiment exists, the Collector prints an error message.

Experiments can be collected into groups. The group is defined in an experiment group file, which is stored by default in the current directory. The experiment group file is a plain text file with a special header line and an experiment name on each subsequent line. The default name for an experiment group file is test.erg. If the name does not end in .erg, an error is displayed and the name is not accepted. Once you have created an experiment group, any experiments you run with that group name are added to the group.

You can manually create an experiment group file by creating a plain text file whose first line is

#analyzer experiment group

and adding the names of the experiments on subsequent lines. The name of the file must end in .erg.

You can also create an experiment group by using the -g argument to the collect command.

The default experiment name is different for experiments collected from MPI programs, which create one experiment for each MPI process. The default experiment name is test.m.er, where m is the MPI rank of the process. If you specify an experiment group group.erg, the default experiment name is group.m.er. If you specify an experiment name, you override these defaults. See Collecting Data From MPI Programs for more information.

Experiments for descendant processes are named with their lineage as follows. To form the experiment name for a descendant process, an underscore, a code letter and a number are added to the stem of its creator’s experiment name. The code letter is f for a fork, x for an exec, and c for combination. The number is the index of the fork or exec (whether successful or not). For example, if the experiment name for the founder process is test.1.er, the experiment for the child process created by the third call to fork is test.1.er/_f3.er . If that child process calls exec successfully, the experiment name for the new descendant process is test.1.er/_f3_x1.er .