500 errors and timeout problems when connecting are not always correlated with the site to which you want to connect. Today, for example, the problem that many sites have in common concerns Cloudflare.
If, surfing the web, you often come across 500 errors or messages like connection timed outknow that this is not your problem nor, much less, could it be synonymous with difficulties on the servers of the site you are trying to visit.
The 500 error, as we have seen, is a sign of a web server side problem: a connection problem with the database or an error in the script that is loaded by the server can lead to the display of this code.
However, some users are reporting the appearance of 500 errors and timeout (the connection does not take place within the maximum time allowed) on a large number of Europen sites. Too many to be a mere coincidence. Thus, with a simple check it was discovered that the problem came from a suddenness failure Of Cloudflare.
Cloudflare is a US company that provides a series of services and solutions for the management, security andacceleration of online resources, including websites, applications and network infrastructure. Many Europen websites, for example, use the service of proxying Cloudflare: It enables content delivery acceleration (Cloudflare caches static website content) in its globally distributed servers and placed close to clients. When a user accesses the site, Cloudflare serves that content from the closest geographical location, thus reducing latency and improving loading time of the pages. Cloudflare allows you to optimize the resources published on the page, for example by reducing the size of static files (including images) and makes use of the load balancing to distribute traffic among multiple web servers.
Service proxy Cloudflare also protects against online threats by filtering incoming web traffic and blocking any malicious requests, such as those made by botnets, malicious bots, and DDoS attacks. Uses advanced detection algorithms to automatically identify and mitigate threats, protecting the website from attacks and granting access only to legitimate users.
It can happen, however, that even an infrastructure as optimized and “accident-proof” as that of Cloudflare sometimes presents some problems. Today, for example, many have noticed that the 500 error showed an explicit reference to the well-known Web server nginx: even trying to connect to remote servers that don’t use it.
How is it possible? Precisely due to the fact that it was the Cloudflare infrastructure that temporarily broke down, as confirmed by the company in the dashboard pubblica Cloudflare System Status: “Cloudflare is investigating issues with network performance in Milan. We are working to analyze and mitigate this problem“.
Already in the past few hours there had been routing problems with the data center Cloudflare of Milan and more recently, 500 errors have started popping up connection timed out in an attempt to connect with hundreds of well-known websites.
A trick to check if there are problems reaching a site managed with Cloudflare
Try adding to domain name of a site, the path /cdn-cgi/trace in the address bar. If you get response, instead of a 404 error (indicates a non-existent page), it means that the website uses Cloudflare.
The file /cdn-cgi/trace provides information about connection between the client and the server through Cloudflare’s network service. Here is the meaning of each parameter in the file response:
- fl: A randomly generated identifier for the HTTP request;
- h: The host or domain of the website that requested the /cdn-cgi/trace file;
- ip: The IP address of the client who made the request;
- ts: A timestamp representing when the request was processed;
- visit_scheme: The scheme used for the visit, for example “https”;
- uag: The user agent of the browser or client that made the request;
- colo: The identification code of the Cloudflare data center that handled the request. MXP indicates Milan;
- sliver: Indicates the portion of traffic that passes through Cloudflare data centers;
- http: The version of the HTTP protocol used for the request;
- loc: The geographical location of the client;
- tls: The version of the TLS security protocol used for the connection;
- sni: The name of the server name indicator (Server Name Indication) used during the TLS connection. “plaintext” indicates that an encrypted server name was not used.
- warp: Indicates the status of the service Cloudflare Warpa VPN network service;
- gateway: Indicates the status of the service Cloudflare Gatewaywhich is a security service for Internet traffic;
- rbi: Indicates the status of the service Cloudflare Resolver for Banking Institutionswhich is a DNS service reserved for banking institutions;
- kex: The cryptographic key exchange algorithm used during the connection.
The indication of a data center non-Europen connecting from Europe without using a VPN or the failure to return all the parameters could be a symptom of a problem, for example of difficulties in the routing phase or another network problem involving the Cloudflare infrastructure.