Isao Ohta

22 papers Journal 20Unranked 2
YearRankTypeTitle / Venue / Authors
2023 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Kaito Fujitani, Akinobu Yamaguchi, Yuichi Utsumi, Isao Ohta
2021 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Masaya Takeuchi, Akinobu Yamaguchi, Yuichi Utsumi, Isao Ohta
2018 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Masaya Takeuchi, Akinobu Yamaguchi, Yuichi Utsumi, Isao Ohta
2018 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Isao Ohta
2016 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Yuki Mizutani, Isao Ohta, Kensuke Okubo, Hironori Takimoto
2014 J jnl
IEICE Trans. Electron.
Tadashi Kawai, Yuma Sumitomo, Akira Enokihara, Isao Ohta, Kei Satoh, Yasunori Suzuki, Hiroshi Okazaki, Shoichi Narahashi
2013 conf
RWS
Yuma Sumitomo, Tadashi Kawai, Akira Enokihara, Isao Ohta, Kei Satoh, Yasunori Suzuki, Hiroshi Okazaki, Shoichi Narahashi
2013 conf
WiSNet
Yuma Sumitomo, Tadashi Kawai, Akira Enokihara, Isao Ohta, Kei Satoh, Yasunori Suzuki, Hiroshi Okazaki, Shoichi Narahashi
2013 J jnl
IEICE Electron. Express
Tadashi Kawai, Isao Ohta, Akira Enokihara
2012 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Hiroaki Ikeuchi, Yuichi Utsumi, Tadashi Kawai, Isao Ohta
2011 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Isao Ohta, Kensuke Okubo
2011 J jnl
IEICE Trans. Electron.
Hiroaki Ikeuchi, Tadashi Kawai, Mitsuyoshi Kishihara, Isao Ohta
2010 J jnl
IEICE Trans. Electron.
Tadashi Kawai, Miku Nakamura, Isao Ohta, Akira Enokihara
2010 J jnl
IEICE Trans. Electron.
Kensuke Okubo, Mitsuyoshi Kishihara, Akifumi Ikeda, Jiro Yamakita, Isao Ohta
2009 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Isao Ohta, Kensuke Okubo, Jiro Yamakita
2008 J jnl
IEICE Trans. Electron.
Tadashi Kawai, Yasuaki Nakashima, Yoshihiro Kokubo, Isao Ohta
2008 J jnl
IEICE Trans. Electron.
Takao Fujii, Isao Ohta, Tadashi Kawai, Yoshihiro Kokubo
2007 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Isao Ohta, Kuniyoshi Yamane
2007 J jnl
IEICE Trans. Electron.
Takao Fujii, Isao Ohta, Tadashi Kawai, Yoshihiro Kokubo
2006 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Isao Ohta, Kuniyoshi Yamane
2005 J jnl
IEICE Trans. Electron.
Mitsuyoshi Kishihara, Kuniyoshi Yamane, Isao Ohta, Tadashi Kawai
2005 J jnl
IEICE Trans. Electron.
Isao Ohta, Tadashi Kawai
s3-storage/s3_test.py
← Index s3-storage/s3_test.py python
#!/usr/bin/env python3
"""
Simple script to test S3 connectivity and download.
Usage: python s3_test.py
"""

import os
import time
import tempfile
from minio import Minio
from minio.error import S3Error
from dotenv import load_dotenv

# Load environment variables
load_dotenv()

def get_minio_client():
    """Create and return a Minio client using credentials from .env file"""
    endpoint = os.getenv("S3_ENDPOINT")
    access_key = os.getenv("S3_ACCESS_KEY")
    secret_key = os.getenv("S3_SECRET_KEY")
    secure = True 
    
    print(f"Connecting to S3 endpoint: {endpoint} (secure={secure})")
    
    return Minio(
        endpoint=endpoint,
        access_key=access_key,
        secret_key=secret_key,
        secure=secure
    )

def test_connection():
    """Test basic connectivity to S3"""
    try:
        client = get_minio_client()
        
        # Try to list buckets as a basic connectivity test
        buckets = client.list_buckets()
        print(f"Successfully connected to S3. Found {len(buckets)} buckets:")
        for bucket in buckets:
            print(f"  - {bucket.name}")
        
        return client
    except Exception as e:
        print(f"Failed to connect to S3: {e}")
        return None

def test_bucket_access(client, bucket_name):
    """Test access to a specific bucket"""
    try:
        exists = client.bucket_exists(bucket_name)
        if exists:
            print(f"Bucket '{bucket_name}' exists and is accessible")
            
            # List a few objects to verify access
            count = 0
            objects = []
            for obj in client.list_objects(bucket_name, recursive=True):
                print(f"  - {obj.object_name} ({obj.size} bytes)")
                objects.append(obj)
                count += 1
                if count >= 5:
                    break
            
            print(f"Found at least {len(objects)} objects in bucket")
            return objects
        else:
            print(f"Bucket '{bucket_name}' does not exist or is not accessible")
            return []
    except Exception as e:
        print(f"Error accessing bucket '{bucket_name}': {e}")
        return []

def test_download(client, bucket_name, object_name):
    """Test downloading a specific object"""
    try:
        print(f"Attempting to download: {object_name}")
        start_time = time.time()
        
        # Create a temporary file to store the downloaded object
        with tempfile.NamedTemporaryFile(delete=False) as temp_file:
            temp_path = temp_file.name
        
        # Download the object
        client.fget_object(bucket_name, object_name, temp_path)
        
        # Check if the file was downloaded successfully
        file_size = os.path.getsize(temp_path)
        elapsed_time = time.time() - start_time
        
        print(f"Download successful: {file_size} bytes in {elapsed_time:.2f} seconds")
        print(f"Average download speed: {file_size/elapsed_time/1024:.2f} KB/s")
        
        # Clean up
        os.unlink(temp_path)
        return True
    except S3Error as e:
        print(f"S3 Error during download: {e}")
        return False
    except Exception as e:
        print(f"Error downloading object: {e}")
        return False

def main():
    """Main function to run all tests"""
    print("=== S3 Connectivity Test ===")
    
    # Test basic connectivity
    client = test_connection()
    if not client:
        return
    
    # Get bucket name from environment variable
    bucket_name = "redb"
    print(f"\n=== Testing Access to Bucket: {bucket_name} ===")
    objects = test_bucket_access(client, bucket_name)
    
    if objects:
        # Test downloading the first object
        first_object = objects[0].object_name
        print(f"\n=== Testing Download of Object: {first_object} ===")
        test_download(client, bucket_name, first_object)
        
        # If the first one worked, let's try a specific file from the error log
        print(f"\n=== Testing Download of Specific Object ===")
        specific_object = "00/06/00062073114defac39cb7ab9cb99a0b77c535a09a241c60d47ddd0b6431629f1.zip"
        test_download(client, bucket_name, specific_object)

if __name__ == "__main__":
    main()