![]() However some web sites don’t like being accessed with a mixture of different IP addresses and hostnames on different devices-perhaps because they use absolute links or some kind of host header validation. The quickest way to view a locally-hosted site on a mobile device is to simply use the local IP address of your computer in the “host” portion of the URL, for example. How can you test the site using the same URL on a mobile device (that is, a real mobile device, not an emulator)-without jailbreaking the device, using a DNS server, or paying for additional software? In this post I’ll describe a way to do exactly that. #Dns for squidman mac os#Let’s say the local site is hosted on Mac OS X, and you access it with a URL containing a hostname defined locally in the Mac’s “hosts” file, such as. If you have a locally-hosted version of a web site for testing or development, you’ll almost certainly want to test it on a mobile device. #Dns for squidman mac os x#Remember that a dnsserver is small and, if unused, will be swapped out.Testing a Mac OS X web site using a local hostname on a mobile device In other words, if you have only ever seen at most three dnsserver processes in use, make at least five. A good rule of thumb is to make sure you have at least the maximum number of dnsservers squid has ever needed on your system, and probably add two to be on the safe side. It's very important that there are enough dnsserver processes to cope with every access you will need, otherwise squid will stop occasionally. This is why the dnsserver is a separate process, so that these processes can block, without causing blocking in squid. Since there is only one squid process, everyone who uses the cache would have to wait each time the routine was called. The dnsserver processes were originally used by squid because the gethostbyname(3) library routines used to convert web sites names to their internet addresses blocks until the function returns (i.e., the process that calls it has to wait for a reply). I have "dnsserver" processes that aren't being used, should I lower the number in "nf"? If your DNS traffic must pass through one or more routers, this could be causing unnecessary delays. Instead you should try use a DNS resolver on a different host, but on the same LAN. Normally we do not recommend running Squid and Resolver on the same host. If the last dnsserver has zero requests, then you definately have enough.Īnother factor which affects the DNS service time is the proximity of your DNS resolver. If there is not an obvious decreasing trend, then you need to increase the number of dns_children in the configuration file. The last dnsserver should have serviced relatively few requests. Ideally, you should see that the first dnsserver handles a lot of requests, the second one less than the first, etc. It is not limited to single request-response blocking.įirst, find out if you have enough dnsserver processes running by looking at the SquidFaq/CacheManager dns output. Use the internal DNS resolver now built into Squid. My ''dnsserver'' average/median service time seems high, how can I reduce it? To increase it beyond that value, you would have to edit the source code. Note that in some versions, Squid limits dns_children to 32. To alleviate this condition, you need to either (1) increase the number of dnsserver processes by changing the value for dns_children in your config file, or (2) switch to using Squid's internal DNS client code. When all dnsserver processes are busy, Squid queues up requests, but only to a certain point. Each dnsserver program can only handle one request at a time. This means that you are using external dnsserver processes for lookups, and all processes are busy, and Squid's pending queue is full. However we would suggest that you file a bug if you find that the internal DNS process does not work as you would expect.ĭnsSubmit: queue overload, rejecting blah configure time using -disable-internal-dns. If you have reason to use the old style dnsserver process you can build it at. It is much faster and can scale to match traffic levels without needing a reconfigure. The dnsserver processes do not cache DNS lookups, that is implemented inside the squid process.Īn internal DNS client was integrated into the main Squid binary in Squid-2.3. Squid must use non-blocking I/O at all times, so DNS lookups are implemented external to the main process. This is necessary because the gethostbyname(3) function blocks the calling process until the DNS query is completed. The dnsserver is a process forked by squid to resolve IP addresses from domain names. I have "dnsserver" processes that aren't being used, should I lower the number in "nf"?.My ''dnsserver'' average/median service time seems high, how can I reduce it?.dnsSubmit: queue overload, rejecting blah. ![]()
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