我最近一直在深入了解Golang并发,特别是通道和工作池的使用。我想比较Go和Python之间的性能(正如许多人所做的那样),因为我主要读到Go在并发性方面优于Python。因此,我编写了两个程序来扫描AWS帐户的S3存储桶,并报告总大小。我在一个帐户上执行此操作,该帐户有75个以上的存储桶,总计超过几TB的数据
我惊讶地发现我的Python实现比我的Go实现快了近2倍。基于我读过的所有基准和文献,这让我感到困惑。这让我相信我没有正确地实现我的Go代码。在观看这两个程序运行时,我注意到Go实现只使用了我CPU的15%,而Python使用了>;85%. 我是否错过了Go的一个重要步骤,或者在实施过程中遗漏了什么?提前谢谢
Python代码:
'''
Get the size of all objects in all buckets in S3
'''
import os
import sys
import boto3
import concurrent.futures
def get_s3_bucket_sizes(aws_access_key_id, aws_secret_access_key, aws_session_token=None):
s3client = boto3.client('s3')
# Create the dictionary which will be indexed by the bucket's
# name and has an S3Bucket object as its contents
buckets = {}
total_size = 0.0
#
# Start gathering data...
#
# Get all of the buckets in the account
_buckets = s3client.list_buckets()
cnt = 1
with concurrent.futures.ThreadPoolExecutor(max_workers=50) as executor:
future_bucket_to_scan = {executor.submit(get_bucket_objects, s3client, bucket): bucket for bucket in _buckets["Buckets"]}
for future in concurrent.futures.as_completed(future_bucket_to_scan):
bucket_object = future_bucket_to_scan[future]
try:
ret = future.result()
except Exception as exc:
print('ERROR: %s' % (str(exc)))
else:
total_size += ret
print(total_size)
def get_bucket_objects(s3client, bucket):
name = bucket["Name"]
# Get all of the objects in the bucket
lsbuckets = s3client.list_objects(Bucket=name)
size = 0
while True:
if "Contents" not in lsbuckets.keys():
break
for content in lsbuckets["Contents"]:
size += content["Size"]
break
return size
#
# Main
#
if __name__=='__main__':
get_s3_bucket_sizes(os.environ.get("AWS_ACCESS_KEY_ID"), os.environ.get("AWS_SECRET_ACCESS_KEY"))
Go代码:
package main
import (
"fmt"
"sync"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/awserr"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/s3"
)
type S3_Bucket_Response struct {
bucket string
count int64
size int64
err error
}
type S3_Bucket_Request struct {
bucket string
region string
}
func get_bucket_objects_async(wg *sync.WaitGroup, requests chan S3_Bucket_Request, responses chan S3_Bucket_Response) {
var size int64
var count int64
for request := range requests {
bucket := request.bucket
region := request.region
// Create a new response
response := new(S3_Bucket_Response)
response.bucket = bucket
sess, err := session.NewSession(&aws.Config{
Region: aws.String(region),
})
s3conn := s3.New(sess)
resp, err := s3conn.ListObjectsV2(&s3.ListObjectsV2Input{
Bucket: aws.String(bucket),
})
if err != nil {
if awsErr, ok := err.(awserr.Error); ok {
switch awsErr.Code() {
case "NoSuchBucket":
response.err = fmt.Errorf("Bucket: (%s) is NoSuchBucket. Must be in process of deleting.", bucket)
case "AccessDenied":
response.err = fmt.Errorf("Bucket: (%s) is AccessDenied. You should really be running this with full Admin Privaleges", bucket)
}
} else {
response.err = fmt.Errorf("Listing Objects Unhandled Error: %s ", err)
}
responses <- *response
continue
}
contents := resp.Contents
size = 0
count = 0
for i:=0; i<len(contents); i++ {
size += *contents[i].Size
count += 1
}
response.size = size
response.count = count
responses <- *response
}
wg.Done()
}
func main() {
var err error
var size int64
var resp *s3.ListBucketsOutput
var wg sync.WaitGroup
sess, _ := session.NewSession()
s3conn := s3.New(sess)
// Get account bucket listing
if resp, err = s3conn.ListBuckets(&s3.ListBucketsInput{});err != nil {
fmt.Println("Error listing buckets: %s", err)
return
}
buckets := resp.Buckets
size = 0
// Create the buffered channels
requests := make(chan S3_Bucket_Request , len(buckets))
responses := make(chan S3_Bucket_Response, len(buckets))
for i := range buckets {
bucket := *buckets[i].Name
resp2, err := s3conn.GetBucketLocation(&s3.GetBucketLocationInput{
Bucket: aws.String(bucket),
})
if err != nil {
fmt.Printf("Could not get bucket location for bucket (%s): %s", bucket, err)
continue
}
wg.Add(1)
go get_bucket_objects_async(&wg, requests, responses)
region := "us-east-1"
if resp2.LocationConstraint != nil {
region = *resp2.LocationConstraint
}
request := new(S3_Bucket_Request)
request.bucket = bucket
request.region = region
requests <- *request
}
// Close requests channel and wait for responses
close(requests)
wg.Wait()
close(responses)
cnt := 1
// Process the results as they come in
for response := range responses {
fmt.Printf("Bucket: (%s) complete! Buckets remaining: %d\n", response.bucket, len(buckets)-cnt)
// Did the bucket request have errors?
if response.err != nil {
fmt.Println(response.err)
continue
}
cnt += 1
size += response.size
}
fmt.Println(size)
return
}
很抱歉,我没有机会全面回顾这一点,但我的答案是:这些解决方案在并发性方面似乎并不等同。三件事突然出现:
GetBucketLocation
)的主线程上执行额外的IO调用我的下一个问题是:
相关问题 更多 >
编程相关推荐