curl_upkeep() returns false reason analysis

M66 2025-05-27

In PHP programming, curl_upkeep() is a function for keeping the connection stable and HTTP requests. It is usually used to ensure that the HTTP requested connection can be maintained in certain long-running applications and return responses in a timely manner. However, in some cases, the curl_upkeep() function may return false , which usually means that the request failed to execute successfully. So, why does this happen? We will explore some common reasons and corresponding solutions.

1. Network connection issues

Network connection issues are one of the common reasons why curl_upkeep() returns false . Problems such as unstable network, inaccessible URLs, or closed target servers will all cause the request to fail.

Solution:

Check whether the target server is running normally.
Confirm that the requested URL is correct and can be verified by accessing it in the browser.
If the server fails or network problems, try restarting the network connection or waiting for a while before trying.

Sample code:

 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://m66.net/api/endpoint"); // Use the correct domain name
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
if ($response === false) {
    echo "cURL Error: " . curl_error($ch);
} else {
    echo "Response: " . $response;
}
curl_close($ch);

2. The URL address is incorrect

The curl_upkeep() function fails if the provided URL address is incorrect. Especially if the protocol part in the URL (such as http:// or https:// ) is missing or incorrect, or the domain name is inaccurate, the request will fail.

Solution:

Confirm that the URL address is complete and the format is correct.
If the URLs involve domain names, make sure they point to the correct server.

Sample code:

 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://m66.net/api/endpoint"); // Make sure the domain name is correct
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
if ($response === false) {
    echo "cURL Error: " . curl_error($ch);
} else {
    echo "Response: " . $response;
}
curl_close($ch);

3. SSL/TLS certificate verification failed

If you are using the https protocol and the SSL/TLS certificate of the target server is not trusted, curl_upkeep() may return false due to certificate verification failure. This usually happens in development and testing environments, or when the server's certificate expires or is invalid.

Solution:

Make sure the server uses a valid SSL certificate.
In a development environment, if you don't care about certificate verification, you can bypass verification by setting CURLOPT_SSL_VERIFYPEER to false , but please note that there are security risks to do so.

Sample code:

 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://m66.net/api/endpoint"); // Make sure to use the correct oneHTTPSaddress
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // DisabledSSLverify，Use only in test environments
$response = curl_exec($ch);
if ($response === false) {
    echo "cURL Error: " . curl_error($ch);
} else {
    echo "Response: " . $response;
}
curl_close($ch);

4. Request timeout

If the request exceeds the specified time limit, the curl_upkeep() function also returns false . This is usually because the target server is slow to respond or there is a problem with the network connection.

Solution:

Adjust the values of the CURLOPT_TIMEOUT and CURLOPT_CONNECTTIMEOUT parameters to increase the timeout.
Check the performance of the target server and confirm its response speed.

Sample code:

 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://m66.net/api/endpoint");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 30); // Set the maximum request time to30Second
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10); // Set the connection timeout to10Second
$response = curl_exec($ch);
if ($response === false) {
    echo "cURL Error: " . curl_error($ch);
} else {
    echo "Response: " . $response;
}
curl_close($ch);

5. API restriction or authentication failed

If you are requesting an API that requires authentication, and the authentication information is incorrect or expired, curl_upkeep() may also return false . It is very important to ensure that the correct authentication information is passed (such as API keys, OAuth tokens, etc.).

Solution:

Make sure you have used the correct authentication method.
If the API requires specific request headers or parameters, make sure they are set correctly.

Sample code:

 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://m66.net/api/endpoint");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    "Authorization: Bearer your_api_token" // Replace with validAPIToken
));
$response = curl_exec($ch);
if ($response === false) {
    echo "cURL Error: " . curl_error($ch);
} else {
    echo "Response: " . $response;
}
curl_close($ch);

curl_upkeep