我们有一个API服务器，正在使用HTTP Load Balancer。我们发现，如果HTTP请求的数据很大，L7负载均衡器会返回502错误。
我们已确认在没有Load Balancer（直接访问API服务器）的情况下访问API时它可以正常工作。
这个问题可能是一个类似的问题。 HTTP Load Balancer cuts out part of a large request body
有人说使用L4网络负载均衡器是一种可能的解决方案，但我们不希望出于某些原因使用它，例如基于URL的负载均衡和跨区域负载均衡。
// Response OK (data size is 1024)
curl -H "Content-Type: application/json" -X POST -d '{"xx": "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}' https://xxxxxxxxxxxxxxx.com/xx/xxxxxxxxxxxx/xxxxxxxxx
// Response NG (data size is 1025)
curl -H "Content-Type: application/json" -X POST -d '{"xx": "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}' https://xxxxxxxxxxxxxxx.com/xx/xxxxxxxxxxxx/xxxxxxxxx
LB似乎对发布数据的大小有一些限制。测试显示限制大约为1024字节。
UPDATE1
@chaintng saved me。链接帖子上有人说如果帖子数据超过1024字节，则curl会添加"Expect: 100-continue Header"。
// Response NG (data size is 1025. without "Expect: ")
curl -H "Content-Type: application/json" -X POST -d '{"xx": "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}' https://xxxxxxxxxxxxxxx.com/xx/xxxxxxxxxxxx/xxxxxxxxx
// Response OK (data size is 1025. with "Expect: ")
curl -H "Expect: " -H "Content-Type: application/json" -X POST -d '{"xx": "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}' https://xxxxxxxxxxxxxxx.com/xx/xxxxxxxxxxxx/xxxxxxxxx
答案 0 :(得分：3)
此问题的引用Curl to Google Compute load balancer gets error 502
这是因为当请求大型POST主体定义标头为Expect: 100-continue
Google L7负载平衡不支持（在本文档https://cloud.google.com/compute/docs/load-balancing/http/中说明）
您所要做的就是通过在执行curl之前设置标题来忽略此行为。
例如用PHP
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Expect:']);