PHP cURL返回false，errno43 BAD_FUNCTION_ARGUMENT问题排查求助

在运行PHPUnit测试的服务A中，向API服务B发送多个cURL请求时，达到固定请求次数后curl_exec()返回false，错误码为43（BAD_FUNCTION_ARGUMENT）。该错误始终出现在测试集的固定测试点，移除错误前的测试后，错误会转移到下一个使用cURL的测试，看起来像是触发了某个硬限制。

已尝试以下配置但无效：

• 设置CURLOPT_TIMEOUT => 120、CURLOPT_CONNECTTIMEOUT => 120，PHP脚本超时设为set_time_limit(0)（无限）
• 将php.ini中的memory_limit从128M提升至512M并重启服务器
• 设置CURLOPT_FORBID_REUSE => true，添加Connection: close请求头

错误前最后一次成功的cURL请求 #

* Host localhost:80 was resolved.
* IPv6: ::1
* IPv4: 127.0.0.1
*   Trying [::1]:80...
* Connected to localhost (::1) port 80
> GET /user/2645f3b7-a187-47c0-95d3-0ab1696501eb/ HTTP/1.1
Host: localhost
Accept: */*
Accept-Encoding: deflate, gzip, br, zstd
Connection: close
Authorization: Bearer: eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJrZXlzIjp7lciJ9.JivFp5Rp6YcQ5KkcEp_7WiVB2SmIRdnXcsg86r3eGIE

* Request completely sent off
< HTTP/1.1 200 OK
< Date: Wed, 08 May 2024 12:28:43 GMT
< Server: Apache/2.4.54 (Unix) OpenSSL/1.0.2u PHP/8.2.0 mod_wsgi/3.5 Python/2.7.18 mod_fastcgi/mod_fastcgi-SNAP-0910052141 mod_perl/2.0.11 Perl/v5.30.1
< X-Powered-By: PHP/8.2.0
< Set-Cookie: _ssid=0qupDtygjuhsOEQyDYilnLSfcEymOUDKDwdTVXEyQqC68D3b8tkPH6-SCby2qcKB%2CsJU1%2C4vbk39hLbeT%2CWGgdh%2Ctn9C4SOerZ2YHh6VWIrsI3Br8X-Jyu1XCfsMk8Lu; expires=Wed, 15 May 2024 12:28:43 GMT; Max-Age=604800; path=/; HttpOnly; SameSite=Strict
< Expires: Thu, 19 Nov 1981 08:52:00 GMT
< Cache-Control: no-store, no-cache, must-revalidate
< Pragma: no-cache
< Access-Control-Allow-Origin: *
< Content-Length: 1208
< Connection: close
< Content-Type: application/json
< 
* Closing connection

对应的curl_info #

array(40) {
  ["url"]=>
  string(57) "http://localhost/user/2645f3b7-a187-47c0-95d3-0ab1696501eb/"
  ["content_type"]=>
  string(16) "application/json"
  ["http_code"]=>
  int(200)
  ["header_size"]=>
  int(703)
  ["request_size"]=>
  int(0)
  ["filetime"]=>
  int(-1)
  ["ssl_verify_result"]=>
  int(0)
  ["redirect_count"]=>
  int(0)
  ["total_time"]=>
  float(1.024873)
  ["namelookup_time"]=>
  float(5.2E-5)
  ["connect_time"]=>
  float(0.000393)
  ["pretransfer_time"]=>
  float(0.000602)
  ["size_upload"]=>
  float(44)
  ["size_download"]=>
  float(114)
  ["speed_download"]=>
  float(111)
  ["speed_upload"]=>
  float(42)
  ["download_content_length"]=>
  float(114)
  ["upload_content_length"]=>
  float(44)
  ["starttransfer_time"]=>
  float(1.024833)
  ["redirect_time"]=>
  float(0)
  ["redirect_url"]=>
  string(0) ""
  ["primary_ip"]=>
  string(3) "::1"
  ["certinfo"]=>
  array(0) {
  }
  ["primary_port"]=>
  int(80)
  ["local_ip"]=>
  string(3) "::1"
  ["local_port"]=>
  int(59910)
  ["http_version"]=>
  int(2)
  ["protocol"]=>
  int(1)
  ["ssl_verifyresult"]=>
  int(0)
  ["scheme"]=>
  string(4) "HTTP"
  ["appconnect_time_us"]=>
  int(0)
  ["connect_time_us"]=>
  int(393)
  ["namelookup_time_us"]=>
  int(52)
  ["pretransfer_time_us"]=>
  int(602)
  ["redirect_time_us"]=>
  int(0)
  ["starttransfer_time_us"]=>
  int(1024833)
  ["total_time_us"]=>
  int(1024873)
  ["effective_method"]=>
  string(4) "POST"
  ["capath"]=>
  string(0) ""
  ["cainfo"]=>
  string(0) ""
}

错误触发时的请求curl_info（无verbose信息） #

array(40) {
  ["url"]=>
  string(57) "http://localhost/role/ROLE-RKX0TRLT1QGF/"
  ["content_type"]=>
  NULL
  ["http_code"]=>
  int(0)
  ["header_size"]=>
  int(0)
  ["request_size"]=>
  int(0)
  ["filetime"]=>
  int(-1)
  ["ssl_verify_result"]=>
  int(0)
  ["redirect_count"]=>
  int(0)
  ["total_time"]=>
  float(0)
  ["namelookup_time"]=>
  float(0)
  ["connect_time"]=>
  float(0)
  ["pretransfer_time"]=>
  float(0)
  ["size_upload"]=>
  float(0)
  ["size_download"]=>
  float(0)
  ["speed_download"]=>
  float(0)
  ["speed_upload"]=>
  float(0)
  ["download_content_length"]=>
  float(-1)
  ["upload_content_length"]=>
  float(-1)
  ["starttransfer_time"]=>
  float(0)
  ["redirect_time"]=>
  float(0)
  ["redirect_url"]=>
  string(0) ""
  ["primary_ip"]=>
  string(0) ""
  ["certinfo"]=>
  array(0) {
  }
  ["primary_port"]=>
  int(0)
  ["local_ip"]=>
  string(0) ""
  ["local_port"]=>
  int(0)
  ["http_version"]=>
  int(0)
  ["protocol"]=>
  int(0)
  ["ssl_verifyresult"]=>
  int(0)
  ["scheme"]=>
  string(0) ""
  ["appconnect_time_us"]=>
  int(0)
  ["connect_time_us"]=>
  int(0)
  ["namelookup_time_us"]=>
  int(0)
  ["pretransfer_time_us"]=>
  int(0)
  ["redirect_time_us"]=>
  int(0)
  ["starttransfer_time_us"]=>
  int(0)
  ["total_time_us"]=>
  int(0)
  ["effective_method"]=>
  string(3) "GET"
  ["capath"]=>
  string(0) ""
  ["cainfo"]=>
  string(0) ""
}

从日志可见，cURL甚至未初始化就崩溃，错误码为43 BAD_FUNCTION_ARGUMENT，但无法确定原因。单独运行包含该错误测试的子集时一切正常，现寻求排查建议，比如未尝试过的cURL选项或Apache连接限制相关方向。

内容的提问来源于stack exchange，提问作者Gijs