Details about TCP_MISS/000 in Squid access.log

I noticed some TCP_MISS/000 entries in Squid access_log this afternoon, as what I saw 3 years ago.
As we know that TCP_MISS means the URL has no stored objects in cache, and TCP_MISS/000 is the bit usually means aborted, indicating there’s no reply to the request before the client aborted the connection.

It might be caused by the following reasons:

1, The client aborted request before SQUID could return any data.
2, The website might be unavailable, due to DNS issue, network issue or an abnormal running web server.
For DNS issues, we need to check whether the dns server that used by SQUID is working as expected or not.
For network issues, we might need to check network connection status, packet lost, transfer latency or something else.
To check a web server, you can send some command to its service port, usually, you can follow this command:

$ telnet Your.Server.tld 80 [return] GET / HTTP/1.0 [return][return]
If there is no output, you might need to restart the web server.

5 thoughts on “Details about TCP_MISS/000 in Squid access.log

  1. I recently came across your blog and have been reading along. I thought I would leave my first comment. I don’t know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.


  2. Thank you for your detailed information about MISS000,at the beginning,I try some methods to solve the issuses.but I can’t solve it ,at last,wo follow your way to telnet the website ,and I understand,The website limit our proxy IP.So funny,Thank you.

  3. Hey, Joseph. It was pretty interesting your info, it helped me to understand this /000 problem. The question is: why my Squid is not loading a website that I can load without squid? If I use a computer, on my network, squid-free, works fine. If it under Squid, it resolves the DNS but it gives me “no route to host”, “connection timeout”, or other issues and it doesn’t load the website. The other websites are loading normally. I changed already almost everything on my Squid.conf and nothing solved the problem.

  4. @Harry, Can you access from the squid server? Any output from the command “telnet 80”?

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