解决"崩溃后Nexus Blob大小过大"的问题，可以采取以下几个步骤：

1. 清理过期的Blob：使用Nexus Blob服务提供的API，可以通过查询Blob的元数据信息来判断哪些Blob已经过期，然后通过删除API来清理这些过期的Blob。以下是一个示例代码：

import requests

def delete_blob(blob_url):
    response = requests.delete(blob_url)
    if response.status_code == 204:
        print("Blob deleted successfully")
    else:
        print("Failed to delete blob")

def cleanup_expired_blobs():
    # 查询所有Blob的元数据信息
    response = requests.get("https://nexus_blob_service/api/blobs")
    if response.status_code == 200:
        blobs = response.json()
        for blob in blobs:
            # 判断Blob是否过期
            if blob['expires'] < time.time():
                delete_blob(blob['url'])
    else:
        print("Failed to get blobs")

cleanup_expired_blobs()

2. 压缩Blob：如果清理过期的Blob后仍然存在较大的Blob，可以尝试将Blob进行压缩来减小其大小。以下是一个示例代码：

import requests
import gzip

def compress_blob(blob_url):
    response = requests.get(blob_url)
    if response.status_code == 200:
        compressed_blob = gzip.compress(response.content)
        # 上传压缩后的Blob
        upload_compressed_blob(compressed_blob)
    else:
        print("Failed to download blob")

def upload_compressed_blob(compressed_blob):
    response = requests.post("https://nexus_blob_service/api/blobs", data=compressed_blob)
    if response.status_code == 201:
        print("Compressed blob uploaded successfully")
    else:
        print("Failed to upload compressed blob")

def compress_blobs():
    # 查询所有Blob的元数据信息
    response = requests.get("https://nexus_blob_service/api/blobs")
    if response.status_code == 200:
        blobs = response.json()
        for blob in blobs:
            compress_blob(blob['url'])
    else:
        print("Failed to get blobs")

compress_blobs()

以上代码示例仅供参考，具体实现需要根据实际情况进行调整和优化。