简单的请求在 Chrome 中停滞了很长时间

Question

这是一个简单的 get 请求，它返回两个小文件。内容下载时间为 2.71 毫秒。但是，请求完成时间为 4.15 秒。Chrome 工具显示请求已停止。它没有排队，并且连接数少于 6 个。到底是什么原因导致停滞不前呢？

  t=88458 [st=  16]      HTTP_CACHE_CREATE_ENTRY  [dt=0]
t=88458 [st=  16]      HTTP_CACHE_ADD_TO_ENTRY  [dt=0]
t=88458 [st=  16]     +HTTP_STREAM_REQUEST  [dt=3408]
t=88458 [st=  16]        HTTP_STREAM_JOB_CONTROLLER_BOUND
                         --> source_dependency = 532266 (HTTP_STREAM_JOB_CONTROLLER)
t=91866 [st=3424]        HTTP_STREAM_REQUEST_BOUND_TO_JOB
                         --> source_dependency = 532267 (HTTP_STREAM_JOB)
t=91866 [st=3424]     -HTTP_STREAM_REQUEST
t=91867 [st=3425]      URL_REQUEST_DELEGATE  [dt=0]
t=91867 [st=3425]     +HTTP_STREAM_REQUEST  [dt=293]
t=91867 [st=3425]        HTTP_STREAM_JOB_CONTROLLER_BOUND
                         --> source_dependency = 532317 (HTTP_STREAM_JOB_CONTROLLER)
t=92160 [st=3718]        HTTP_STREAM_REQUEST_BOUND_TO_JOB
                         --> source_dependency = 532318 (HTTP_STREAM_JOB)
t=92160 [st=3718]     -HTTP_STREAM_REQUEST
t=92160 [st=3718]     +HTTP_TRANSACTION_SEND_REQUEST  [dt=0]
t=92160 [st=3718]        HTTP_TRANSACTION_SEND_REQUEST_HEADERS