http://www.perlmonks.org?node_id=1231238

evergreen has asked for the wisdom of the Perl Monks concerning the following question:

Hello monks,

I am using Apache2::Request to parse a multi-part Http post in a .mpl script running under apache mod_perl. The Http post comes from an upstream system.

Here is the relevant part of the script.

$r = shift;
$cgi = Apache2::Request->new($r);
$r->discard_request_body;   # efficiently parses the request body
my $parser_status = $cgi->param_status();
if ($parser_status ne 'Success')
{
    $parser_error = $parser_status;
}

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The problem is that the call to param_status() returns "Internal apreq error" and further down in the script, it finds that an expected multi-part content is missing.

The post is retried by the upstream system until it succeeds, and after 10-15 retries it eventually succeeds, meaning there was no apreq error when it succeeded and the expected multi-part is present.

Is there any way to get more information about why there is an "Internal apreq error"?

Thanks.

Replies are listed 'Best First'.
Re: Apache2::Request Internal apreq error
by thanos1983 (Parson) on Mar 14, 2019 at 09:05 UTC

    Hello evergreen,

    My answer is not Perl related but my troubleshooting approach on this would be to capture a tcpdump (LinuxOS) if you are running on (WindowsOS) wireshark. By doing so you will see the package arriving and you will explicitly see what is the reply/error back.

    Update: From the documentation Apache2::Request/param this should give more data:

    $req->args_status(1); # set error state for query-string parser
ok $req->param_status == 1;
 
$foo = $req->param("foo");
ok $foo == 1;
eval { @foo = $req->param("foo") };
ok $@->isa("Apache2::Request::Error");
undef $@;
eval { my $not_found = $req->param("non-existent-param") };
ok $@->isa("Apache2::Request::Error");
 
$req->args_status(0); # reset query-string parser state to "success"

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    Hope this helps, BR.

    Seeking for Perl wisdom...on the process of learning...not there...yet!
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      Thanks thanos1983, I tried tcpdump and Wireshark, but the content of the post requests looks good and the multi-part attachments are there, but somehow it is not being parsed.

      I also see this in apache error log: 
      [Thu Mar 14 18:40:04 2019] [error] [client 17.108.244.6] (70008)Partia
+l results are valid but processing is incomplete: ap_get_brigade fail
+ed during prefetch
[Thu Mar 14 18:40:04 2019] [error] Internal apreq error

      [download]
      Will update here if I find anything.
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