Hot answers tagged

42

As Ron Garrity says, you can use Curl like this: curl -Iv http://www.aptivate.org 2>&1 | grep -i 'connection #0' And it outputs these two lines if keep-alive is working: * Connection #0 to host www.aptivate.org left intact * Closing connection #0 And if keep-alive is not working, then it just outputs this line: * Closing connection #0 The output ...


34

Lack of IPv6 support on your site will hurt some of your users. According to stats published by Google 20-25% of users currently have IPv6. A large fraction of those users will need to go through some kind of NAT to reach IPv4-only services, which will make connectivity less reliable. The fraction of users without any IPv4 connectivity whatsoever is ...


31

Foreword Update in 2016. Things are evolving, all servers are getting better, they all support SSL and the web is more amazing than ever. Unless stated, the following is targeted toward professionals in business and start-ups, supporting thousands to millions of users. These tools and architectures require a lot of users/hardware/money. You can try this ...


28

If you have a fast wide-area network you will find that sftp and scp are about the same speed, which is slow. They both suffer from performance problems in the underlying openssh. With modern hardware, this is not due to encryption overhead, but rather due to problems with the openssh implementation - it implements its own internal windowing mechanism ...


27

The website runs on a server process. When you shut down the server process, the server does not magically turn off. Also not when you misconfigure your firewall (and block port 80) neither does the server go off nor does the ICMP rule in the firewall get deleted.


18

The additional security surface java puts into your environment is complex, and it's important not to ignore it or try to simplify it away. Firstly, there is the horrible record the JRE has for having security bugs. It's hard to point out a specific one, and this is the scary part - the bugs are overwhelmingly unspecified vulnerabilities with unspecified ...


17

Well, 1.1.1.1 is an IP address. As far as who it is - it's public address space that bad internet citizens tend to use as a placeholder: inetnum: 1.1.1.0 - 1.1.1.255 netname: Debogon-prefix descr: APNIC Debogon Project descr: APNIC Pty Ltd country: AU admin-c: AR302-AP tech-c: AR302-AP mnt-by: ...


14

All other answers are pre-2010, hence adding an updated comparison. Nginx A full web server, other features can also be used. Eg: HTTP Compression SSL Support Very light weight as Nginx was designed to be light from the start. Near Varnish caching performance Close to HAProxy load balancing performance Varnish best for complex caching scenarios and ...


14

Depending on your version of chmod, you may be able to do this: chmod -R . ug+rwX,o+rX,o-w Note the capital X. This sets the executable bit on directories and files that already have any of the execute bit already set. Note that you can only use capital X with '+', not '=' or '-'.


14

This error seems to come from a Gunicorn backend, not from Nginx. You can change it's limit by passing the parameter --limit-request-line or set limit_request_line. You can see a description here.


12

First, my condolences on your mentor's hospitalization and your baptism by fire into system administration. Second, my condolences on your data loss. I sincerely hope you have backups. To summarize your situation: You have a three-drive RAID array (presumably a RAID-5). This is one "Logical Drive" (the 3 disks are handled by the RAID controller, and ...


12

question 2 It looks like the name servers and actual host for YOGOTAGIFT.COM are registered through ENOM, Inc. The site is hosted at EHOST-SERVICES212.COM. Try sending both spam reports and DMCA takedown notices to eNom and the server host. eNom abuse page is http://www.enom.com/help/abusepolicy.aspx question 4 : Honeytokens Seed your mailing list and ...


11

I suggest you reevaluate your reasons for wanting to go the commercial route rather than using an opensource solution such as Squid. Squid is used by many large ISPs worldwide and is quite likely the most mature web cache and proxy available. Apart from the cost benefit of not requiring any license fees, Squid has an active community and hundreds of code ...


11

That is a very intelligent question and a clear cut source of confusion when ops and devs talk. It means different things depending on context, and especially so in a web hosting context. root can as far as I know officially mean at least: the system full access privileges user. the file system base directory, a.k.a. / the web server shared file system ...


10

Traceroute uses ICMP protocol to reach an address, and a HTTP server use HTTP protocol, different ports, and different approaches. I can reach an address via ICMP echo request but, if the port I'm trying to communicate is closed or freezed somehow, I'll get a timeout error. And if you're sure the server is up and the port is up (listening), is better to ...


9

Giving each website its own address makes it easier to see which website traffic is for on the network. This can help with accounting, attack detection and prevention and things like that. It may also make it easier to move a website to a different server because you can just move the address with it. If you're not doing things like that the benefits are ...


8

Yes, it is normal that non-persistent connections take longer to send first byte of data. This is because the IP address has to be resolved from the DNS, the TCP connection has to be set up, then the SSL/TLS layer has to be initialized, and only after that actual data can be sent. DNS lookup is not performed on a persistent connection, because there ...


7

I also looked at this on the Nginx wiki and other blogs and the best way performance wise is to do the following: To redirect from www.example.com to example.com using nginx (version 1.0.12 at time of writing). server { server_name www.example.com; rewrite ^ $scheme://example.com$request_uri permanent; # permanent sends a 301 redirect whereas ...


7

It's not quite what you think. Heroku is not serving up multiple SSL certs on a single IP address. If you perform an nslookup against different Hostname SSL deployments, for example, you will find that they each point to a different Amazon ELB. Therein lies the secret sauce. When a customer requests Hostname-based SSL, an ELB is provisioned for them and ...


7

You could try ab -n 500 -c 5 -k http://www.domain.com/ and look via top, if 5 workers are constantly serving the requests keepalive should work (-k) switch. Do the same without -k and see the difference. Cheers Izac


7

There will be some processing overhead to establish the SSL connection, but on modern boxes and lightly loaded web sites that probably won't be very noticeable. If you have forums where users are posting images sourced from outside your website, people will see an SSL mixed content warning (your site is SSL, but there are assets that are not SSL). ...


7

as per uSlackr. It appears that currently both of your name servers are not answering.. qweop.com. 172800 IN NS ns01.000webhost.com. qweop.com. 172800 IN NS ns02.000webhost.com. ;; Received 108 bytes from 192.42.93.30#53(g.gtld-servers.net) in 83 ms ;; connection timed out; no servers could be reached` It probably works for you, since ...


7

Better, shorter, fancier than what ? cd /directory find . -type d -exec chmod 0755 {} + find . -type f -exec chmod 0664 {} +


7

The HTTP protocol allows the client application (usually a web browser) to create HTTP requests containing the name of the web site it wants to contact; this allows multiple web sites to coexist on the same IP address and port. All web servers can be configured to serve different contents based on the name of the web site the client is asking for; also, ...


7

Short answer: NO Long answer: IPv4 and IPv6 are different protocols. In theory you can connect from IPv6 address to IPv4 service, but you need NAT64 for this and this is primary designed for IPv6 only network.


6

Wow - what can I say, this stuff isn't easy is it? but have no fear, nobody is born just knowing this stuff so don't feel bad about it, well not yet anyway. Ultimately this comes down to three main areas; Knowing your likely target audience - this is looking at what the max/ave/min number of users you're likely to see over a given day/week/month is. It's ...


6

The "How Do we know" page for DownorNot implies there is a DNS issue. The status for Just ping also says it cannot resolve the hostname. I am unable to resolve the hostname. How is your DNS handled?


6

From: Determine if HTTP authentication is NTLM or Kerberos http://support.microsoft.com/kb/891032 [...] "Since we are looking over this trace to see if the client is sending authentication information, we can use the TCP segments to track the HTTP GET requests and the response from the server. Here is a snippet from the frame that sends authentication ...


6

Java applications eat up all my RAM The alternative to using RAM is wasting RAM. You can't save it for later. Java is full of vulnerabilities That doesn't really matter because you aren't going to expose the JVM to the world. I presume you aren't going to run any hostile programs, and if you are, Java is safer than most other languages. What matters is ...


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