Ian Hinder

Date: 2010/04/06 11:00:00


Thorn SystemStatistics collects information about the system on which a Cactus process is running and stores it in Cactus variables. These variables can then be output and reduced using the standard Cactus methods such as IOBasic and IOScalar.

1 Purpose

When running a Cactus simulation, there are often features of the system on which it is running which can affect the simulation. For example, Cactus processes take a certain amount of memory, and if this exceeds the memory available on the system, the Cactus process will either start to swap, significantly reducing performance, or will terminate. It can be useful to determine quantities such as memory usage of a Cactus process, and that is the purpose of this thorn. The thorn currently provides grid arrays which are filled with memory-related information.

2 SystemStatistics Parameters

This thorn has no parameters.

3 Examples

IOBasic::outInfo_every                  = 256  
IOBasic::outInfo_reductions             = "minimum maximum"  
IOBasic::outInfo_vars                   = "SystemStatistics::maxrss_mb"  
IOScalar::outScalar_every               = 256  
IOScalar::outScalar_reductions          = "minimum maximum average"  
IOScalar::outScalar_vars                = "SystemStatistics::process_memory_mb"

The resulting screen output would look like this:

Iteration      Time | *TISTICS::maxrss_mb  
                    |   minimum   maximum  
        0     0.000 |        52        54  
      256     0.005 |        53        55  
      512     0.010 |        53        55  
      768     0.015 |        53        55  
     1024     0.020 |        53        55

and the reduced scalar output in systemstatistics::process_memory_mb.maximum.asc would look like this: