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Funz Calculator

The Funz calculator provides compatibility with legacy Java Funz calculator servers, enabling FZ to leverage existing Funz infrastructure.

Overview

Funz is a Java-based framework for computational experiments. The FZ Funz calculator allows Python FZ to communicate with Java Funz calculator servers, providing backward compatibility and integration with existing Funz deployments.

URI Format

funz://[host]:<port>/<code>

Components

  • host (optional): Hostname of the Funz server (default: localhost)
  • port (required): TCP port number of the Funz server
  • code: Model/language code supported by the server (e.g., R, Python, bash)

Examples

Local Funz Server

import fz

results = fz.fzr(
    "input.txt",
    {"param1": [1, 2, 3]},
    model,
    calculators="funz://:5555/R",
    results_dir="results"
)

Remote Funz Server

calculators = "funz://server.example.com:5555/Python"

Multiple Funz Servers

Load balance across multiple calculator servers:

calculators = [
    "funz://server1.example.com:5555/R",
    "funz://server2.example.com:5555/R",
    "funz://server3.example.com:5555/R"
]

Protocol

The Funz calculator uses TCP socket communication with a specific protocol:

Reservation

Before executing a calculation, FZ reserves the calculator:

RESERVE <code>

Server responds with: 

OK

Execution

Files are uploaded and execution is requested:

EXECUTE <working_dir>
FILE <filename> <size_bytes>
<file_content>
...

Result Retrieval

After execution, results are downloaded:

GET <filename>

Server responds with file content.

Unreservation

After completion, the calculator is released:

UNRESERVE

UDP Discovery

Funz servers can advertise themselves via UDP broadcast. FZ can automatically discover available Funz calculators on the local network.

Discovery Process

  1. FZ sends UDP broadcast on port 21001: WHO
  2. Funz servers respond with: FUNZ <host>:<port> <codes>
  3. FZ automatically configures discovered calculators

Automatic Discovery

# FZ automatically discovers Funz servers
results = fz.fzr(
    "input.txt",
    variables,
    model,
    calculators="funz",  # Auto-discover
    results_dir="results"
)

Calculator Configuration

Funz calculators can be configured via JSON files in .fz/calculators/:

{
  "uri": "funz://:5555",
  "models": {
    "R": "R",
    "Python": "Python"
  }
}

Features

File Transfer

  • Automatic upload of input files to Funz server
  • Download of output files after execution
  • Binary file support

Job Management

  • Calculator reservation system prevents conflicts
  • Automatic retry on calculator failure
  • Graceful cleanup on interruption (Ctrl+C)

Multi-Language Support

Funz servers can support multiple languages/codes:

  • R statistical computing
  • Python scripting
  • Bash shell scripts
  • MATLAB/Octave
  • Custom calculation codes

Requirements

  • Java Funz calculator server running and accessible
  • Network connectivity to Funz server
  • Port not blocked by firewall

Setting Up a Funz Server

To start a Java Funz calculator server:

java -jar Funz-Calculator.jar \
  -code R \
  -port 5555 \
  -verbose

For multiple codes:

java -jar Funz-Calculator.jar \
  -code R,Python,bash \
  -port 5555

Model Compatibility

The Funz calculator requires that the model is compatible with the specified code:

model = {
    "varprefix": "$",
    "code": "R",  # Must match calculator code
    "output": {
        "result": "cat output.txt"
    }
}

calculators = "funz://:5555/R"  # Code must match

Examples

R Statistical Analysis

import fz

model = {
    "varprefix": "$",
    "code": "R",
    "output": {
        "mean": "grep 'Mean:' output.txt | awk '{print $2}'"
    }
}

results = fz.fzr(
    "analysis.R",
    {
        "sample_size": [100, 500, 1000],
        "mean": [0, 10, 20],
        "sd": [1, 2, 5]
    },
    model,
    calculators="funz://:5555/R",
    results_dir="r_results"
)

Python Simulation

calculators = "funz://compute-server.local:5555/Python"

results = fz.fzr(
    "simulation.py",
    {"iterations": [1000, 5000, 10000]},
    model,
    calculators=calculators,
    results_dir="sim_results"
)

Load Balancing

Distribute calculations across multiple Funz servers:

calculators = [
    "funz://node1:5555/R",
    "funz://node2:5555/R",
    "funz://node3:5555/R",
    "funz://node4:5555/R"
]

results = fz.fzr(
    "model.R",
    large_parameter_grid,
    model,
    calculators=calculators,
    n_parallel=4  # Use all 4 servers
)

Troubleshooting

Connection Refused

Check that the Funz server is running:

telnet hostname 5555

Verify firewall rules allow the connection.

Code Not Supported

Ensure the Funz server supports the requested code:

echo "WHO" | nc -u hostname 21001

Check the server's code list in the response.

File Transfer Fails

Large files may require timeout adjustments:

model = {
    "varprefix": "$",
    "timeout": 300  # 5 minutes
}

Calculator Reserved

If a calculator is stuck in reserved state, restart the Funz server:

# Kill existing server
pkill -f "Funz-Calculator"

# Restart
java -jar Funz-Calculator.jar -code R -port 5555

See Also