poet/README.md
2021-02-17 19:57:08 +01:00

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Time-stamp: "Last modified 2021-02-08 13:46:00 mluebke"
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# POET
POET is a coupled reactive transport simulator implementing a parallel
architecture and a fast distributed hash table.
## External Libraries
We use external libraries:
- **argh** - https://github.com/adishavit/argh (BSD license)
## Installation
### Requirements
To compile POET you need several software to be installed:
- C/C++ compiler (tested with GCC)
- MPI-Implementation (tested with OpenMPI and MVAPICH)
- R language and environment
- CMake 3.9+
If documantiation should be build during compilation `doxygen`and `graphviz`
must be provided too.
The following R libraries must then be installed:
- [devtools](https://www.r-project.org/nosvn/pandoc/devtools.html)
- [Rcpp](https://cran.r-project.org/web/packages/Rcpp/index.html)
- [RInside](https://cran.r-project.org/web/packages/RInside/index.html)
- [RedModRphree](https://gitext.gfz-potsdam.de/delucia/RedModRphree)
- [Rmufits](https://gitext.gfz-potsdam.de/delucia/Rmufits)
### Compiling source code
The generation of makefiles is done with CMake. So, running
```
cmake . -B build
```
will create the directory `build`. `cd` into it and run `make` to start build
process.
If everything went well you'll find the executable at `build/src/poet`.
During the generation of Makefiles, various options can be specified via `cmake
-D <option>=<value> [...]`. Currently there are the following available options:
- **DHT_Debug**=*boolean* - toggles the output of detailed statistics about DHT
usage (`cmake -D DHT_Debug=ON`). Defaults to *OFF*.
- **BUIL_DOC**=*boolean* - toggles the generation of documantiation during
compilation process. Defaults to *ON*.
### Example: Build from scratch
Assuming that only the C/C++ compiler, MPI libraries, R runtime environment and
CMake have been installed, POET can be installed as follows:
``` sh
# start R environment
$ R
# install R dependencies
> install.packages(c("devtools", "Rcpp", "RInside"))
> devtools::install_git("https://gitext.gfz-potsdam.de/delucia/RedModRphree.git")
> devtools::install_git("https://gitext.gfz-potsdam.de/delucia/Rmufits.git")
> q(save="no")
# cd into POET project root
$ cd <POET_dir>
# Build process
$ mkdir build && cd build
$ cmake -DCMAKE_INSTALL_PREFIX=/home/<user>/poet ..
$ make -j<max_numprocs>
$ make install
```
This will install a POET project structure into `/home/<user>/poet` which is
called hereinafter `<POET_INSTALL_DIR>`. With this version of POET I would not
recommend to install to hierarchies like `/usr/local/` etc.
The correspondending directory tree would look like this:
``` sh
.
└── poet/
├── bin/
│ └── poet
├── data/
│ └── SimDol2D.R
├── docs/
│ └── html/
│ ├── index.html
│ └── ...
└── R_lib/
├── kin_r_library.R
└── parallel_r_library.R
```
The R libraries will be read in during runtime and the paths are hardcoded
absolute paths inside `poet.cpp`. So, if you consider to move `bin/poet` either
change paths of the R source files and recompile POET or also move `R_lib/*`
according to the binary.
To display the generetated html documentation just open `docs/html/index.html`
with the browser of your choice.
## Running
Before POET is ready to run, a working directory must be created. In this
directory you should find the executable file, the R scripts
`<POET_ROOT>/R_lib/kin_r_library.R` and `<POET_ROOT>/R_lib/parallel_r_library.R`
and the simulation description e.g. `<POET_ROOT>/data/chem_problems/SimDol2D.R`.
Run POET by `mpirun ./poet <OPTIONS> <SIMFILE> <OUTPUT_DIRECTORY>` where:
- **OPTIONS** - runtime parameters (explained below)
- **SIMFILE** - simulation described as R script (currently supported:
`<POET_INSTALL_DIR>/data/SimDol2D.R`)
- **OUTPUT_DIRECTORY** - path, where all output of POET should be stored
### Runtime options
The following parameters can be set:
| Option | Value | Description |
|-------------------------|--------------|-----------------------------------------------------------------|
| **-work-package-size=** | *1..n* | size of work packages (defaults to *5*) |
| **-ignore-result** | | disables store of simulation resuls |
| **-dht** | | enabling DHT usage (defaults to *OFF*) |
| **-dht-nolog** | | disabling applying of logarithm before rounding |
| **-dht-signif=** | *1..n* | set rounding to number of significant digits (defaults to *5*) |
| **-dht-strategy=** | *0-1* | change DHT strategy. **NOT IMPLEMENTED YET** (Defaults to *0*) |
| **-dht-size=** | *1-n* | size of DHT per process involved in byte (defaults to *1 GiB*) |
| **-dht-snaps=** | *0-2* | disable or enable storage of DHT snapshots |
| **-dht-file=** | `<SNAPSHOT>` | initializes DHT with the given snapshot file |
#### Additions to `dht-signif`
Only used if no vector is given in setup file. For individual valuies per column
use R vector `signif_vector` in `SIMFILE`.
#### Additions to `dht-snaps`
Following values can be set:
- *0* = snapshots are disabled
- *1* = only stores snapshot at the end of the simulation with name
`<OUTPUT_DIRECTORY>.dht`
- *2* = stores snapshot at the end and after each iteration iteration
snapshot files are stored in <DIRECTORY>/iter<n>.dht
### Example: Running from scratch
We will continue the above example and start a simulation with `SimDol2D.R`,
which is the only simulation supported at this moment. To start the simulation
with 4 processes `cd` into your previously installed POET-dir
`<POET_INSTALL_DIR>/bin` and run:
``` sh
mpirun -n 4 ./poet ../data/SimDol2D.R output
```
After a finished simulation all data generated by POET will be found in the
directory `output`.
You might want to use the DHT to cache previously simulated data points and
reuse them in further time-steps. Just append `-dht` to the options of POET to
activate the usage of the DHT. The resulting call would look like this:
``` sh
mpirun -n 4 ./poet -dht SimDol2D.R output
```
## Examples included (more to come)
- **SimDol2D.R** - simple chemistry (Calcite/Dolomite) on a 50x50 2D grid, 20
time steps 2)
- ~~**SimDolKtz.R** - simple chemistry (Calcite/Dolomite) on Ketzin grid (~650k
elements), 20 time steps The flow snapshots are **NOT INCLUDED** in project
directory but must be provided separately.~~ At this moment **SimDolKtz.R** is
not supported.
## About the usage of MPI_Wtime()
Implemented time measurement functions uses `MPI_Wtime()`. Some important
informations from the OpenMPI Man Page:
For example, on platforms that support it, the clock_gettime() function will be
used to obtain a monotonic clock value with whatever precision is supported on
that platform (e.g., nanoseconds).