See below for more questions (I snipped repetitive stuff that was not necessary for understanding):

Francis Daly Wrote:
-------------------------------------------------------
> On Sun, Feb 06, 2022 at 10:08:49PM -0500, marioja2 wrote:
>
(snip)
> The request that you care about is a POST to a url which includes the
> word Upload.
>
> $ grep -n Upload nginx_strace.26
> 636: 0.000041 recvfrom(15, "POST
> /?/Upload/&q[]=/_eiVamsWTAQ12l6UF7vBn495f4U5LAGxhZ0nSBHjARdRjXwgf35Z7y
> vyZwvKejLSOPeJBrY8J_XpMK"..., 1024, 0, NULL, NULL) = 1024
> 2502: 0.000096 writev(17,
> [{iov_base="\1\1\0\1\0\10\0\0\0\1\1\0\0\0\0\0\1\4\0\1\r\35\3\0\f\200\0
> \1\313QUERY_STRING/Upload/&q[]=/_eiVamsWTAQ12l6UF7vBn495f4U5LAGxhZ0nSB
> HjARdR"..., iov_len=3400}], 1) = 3400
> 2964: 0.000062 writev(15, [{iov_base="HTTP/1.1 200 OK\r\nDate:
> Mon, 07 Feb 2022 01:36:10 GMT\r\nContent-Type: application/json;
> charset=utf-8"..., iov_len=436}, {iov_base="46\r\n", iov_len=4},
> {iov_base="{\"Action\":\"Upload\",\"Result\":{\"ErrorCode\":1,\"Error\
> ":\"File is too big\"}}", iov_len=70}, {iov_base="\r\n", iov_len=2},
> {iov_base="0\r\n\r\n", iov_len=5}], 5) = 517
>
> $ grep -n Upload nginx_strace.25
> 488: 0.000134 recvfrom(15, "POST
> /?/Upload/&q[]=/_eiVamsWTAQ12l6UF7vBn495f4U5LAGxhZ0nSBHjARdRjXwgf35Z7y
> vyZwvKejLSOPeJBrY8J_XpMK"..., 1024, 0, NULL, NULL) = 1024
> 2393: 0.000183 writev(17,
> [{iov_base="\1\1\0\1\0\10\0\0\0\1\1\0\0\0\0\0\1\4\0\1\r\35\3\0\f\200\0
> \1\313QUERY_STRING/Upload/&q[]=/_eiVamsWTAQ12l6UF7vBn495f4U5LAGxhZ0nSB
> HjARdR"..., iov_len=3400}], 1) = 3400
> 2847: 0.000064 writev(15, [{iov_base="HTTP/1.1 200 OK\r\nDate:
> Mon, 07 Feb 2022 01:37:26 GMT\r\nContent-Type: application/json;
> charset=utf-8"..., iov_len=410}, {iov_base="bd\r\n", iov_len=4},
> {iov_base="{\"Action\":\"Upload\",\"Result\":{\"Attachment\":{\"Name\"
> :\"5kplayer-setup (2).exe\",\"TempName\":\"upload-post-"...,
> iov_len=189}, {iov_base="\r\n", iov_len=2}, {iov_base="0\r\n\r\n",
> iov_len=5}], 5) = 610
>

If you look 3 lines above the line with the writev for HTTP/1.1 200 OK you will find that for the nginx_strace.26 log file (which failed with File is too big) the recvfrom says that "X-Powered-By: PHP/7.4.26\r\nServer: RainLoop\r\n" whereas in the nginx_strace.25 (which worked) There is no "X-Powered-By: PHP/7.4.26\r\n", just the "Server:RainLoop\r\n"

> That looks like, in both cases, nginx sent a HTTP success (200 OK)
> message, with differing json body content. One has Result: Attachment;
> the other has Result: ErrorCode.
>
(snip)
>
> Cheers,
>
> f
> --
> Francis Daly francis@daoine.org
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