Re: Socket timeout not working with libUrl
On 1 Feb 2005, at 01:33, Sarah Reichelt wrote: 2) If I open the socket with a domain address, e.g. www.webphotospro.com, Mac OS X does a DNS lookup, puts up the rainbow rotating color cursor, and hangs until the DNS lookup fails. On my machine this takes 60 seconds (apparently it's dependent on how many dns servers you have listed). What happens if you try: hostNameToAddress(www.webphotospro.com) and use the result of that as the address for opening the socket? In my tests, this takes about 4 seconds the first time it is called if I am connected (which is long enough for the SPOD to appear). When I am disconnected, it fails instantly and return empty. This is what libUrl does internally, so if you were connnecting via libUrl it would make no difference. But it might help when opening your own socket connections. Alex Tweedly wrote: The engine can't return a response to the hostnametoaddress query until it gets a response from the DNS server (or the query times out), so it simply blocks until the time-out. That's probably reasonable (or at least unavoidable) for a blocking call like hostNameToAddress, but there needs to be a non-blocking version of it, for use in non-blocking libURL and any other action which is not user-triggered (or even to make the user-interruptable). Right now, libUrl blocks until the socket connection is established, even for non-blocking calls, so even with engine changes, some modification would be needed. Perhaps this part of libUrl should be looked at again. Going back to the original problem. There had been a lot of reports on OS X discussion groups about frequent failed DNS lookups . The typical symptom was a 60-second delay as the first lookup failed, but a subsequent lookup would work immediately. This affected some recent versions of Panther, possibly in combination with some of the security updates. I was affected for a while, but haven'r seen it recently. I'm assuming it was fixed in one of the many OS X updates. I'm just wondering if this was part of the problem. (But this is clearly not conected to Alex's description of the problem when the router is not connected.) Cheers Dave ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Socket timeout not working with libUrl
Sarah, Unfortunately there's two types of being disconnected. One where you've no net connection at all, and one where you're on a LAN, but not connected to the Internet. Here in Cornwall I have only modem access, so I've a LAN but no net connection most of the time, which is how I stumbled across this problem. The issue appears to be how Mac OS X does DNS lookups. The routine lookupd appears to be the culprit, and RunRev would need to modify how they call it to make it non-blocking. -- Frank Web Photos Pro: Software for Photo Bloggers and Other Photo Power Users See us on the web at http://www.webphotospro.com/ On Feb 1, 2005, at 4:59 AM, [EMAIL PROTECTED] wrote: From: Sarah Reichelt [EMAIL PROTECTED] Subject: Re: Socket timeout not working with libUrl To: How to use Revolution use-revolution@lists.runrev.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=US-ASCII; format=flowed 2) If I open the socket with a domain address, e.g. www.webphotospro.com, Mac OS X does a DNS lookup, puts up the rainbow rotating color cursor, and hangs until the DNS lookup fails. On my machine this takes 60 seconds (apparently it's dependent on how many dns servers you have listed). What happens if you try: hostNameToAddress(www.webphotospro.com) and use the result of that as the address for opening the socket? In my tests, this takes about 4 seconds the first time it is called if I am connected (which is long enough for the SPOD to appear). When I am disconnected, it fails instantly and return empty. Sarah ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Socket timeout not working with libUrl
If this is an OS X 10.3.7 issue, some people have been able to kludge a fix for it by entering their ISP's DNS server addresses into the relevant pane in Network preferences. But if it is the identified 10.3.7 problem, you would be likely to have experienced long delays in opening Apple's Mail program. Regards James -- James J Richards [EMAIL PROTECTED] Tel. +44 (0)15394 43063 On 1 Feb, 2005, at 14:17, [EMAIL PROTECTED] wrote: Message: 7 Date: Mon, 31 Jan 2005 18:40:22 +0100 From: R. Hillen [EMAIL PROTECTED] Subject: Re: use-revolution Digest, Vol 16, Issue 103 To: use-revolution@lists.runrev.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=US-ASCII; format=flowed Hello Frank, I would guess that you are using OSX 10.3.7; right? That could explain your DNS-Problem, as Apple has changed its DNS-calls. So If I start Apple Mail, I have to wait 50 seconds. Apple told, that it is a bug, so wait for 10.3.8 or return to 10.3.6. Hope it explains. Richard. ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Socket timeout not working with libUrl
Sarah, Thanks for the reply. After a lot of testing on Mac OS X, I've found that the problem I was having appears to be due to the way that Mac OS X does DNS lookups. Whether or not it's a RunRev bug as well is hard to tell, but I think it might be. Here's some sample code I wrote. This code sends a My5SecondTimeout message to itself, opens a socket, makes an HTTP GET request, waits for the response, and closes the socket. (Note: I had to use this My5SecondTimeout message because setting the socketTimeoutInterval doesn't seem to work). When you run this script and you're not connected to the internet here's what happens: 1) If I open the socket with an ip address, e.g. 64.125.128.80, my 5 second timer will fire, and I can close the socket and exit from the routine. 2) If I open the socket with a domain address, e.g. www.webphotospro.com, Mac OS X does a DNS lookup, puts up the rainbow rotating color cursor, and hangs until the DNS lookup fails. On my machine this takes 60 seconds (apparently it's dependent on how many dns servers you have listed). I'm guessing this is a RunRev bug, but I can't be sure. Basically RunRev hangs for 60 seconds while the DNS lookup takes place during the open socket call -- it doesn't send a socket timeout, and it doesn't the My5SecondTimeout message either. Can confirm this? Thanks, -- Frank on mouseUp set the socketTimeoutInterval to 5000 -- this seems to do nothing, but set it anyway global theIp, socketIsOpen, socketTimedOut put www.webphotospro.com:80 into theIp -- using this causes RunRev to hang for 60 seconds -- put 64.125.128.80:80 into theIp -- using this does not cause a hang put false into socketIsOpen put false into socketTimedOut send My5SecondTimeout to button Ping in 5 seconds -- send a message to myself close socket theIp -- in case it's currently open open socket to theIp with message mySocketOpenMsg wait until socketIsOpen or socketTimedOut with messages if socketTimedOut then close socket theIp answer socket timed out end if end mouseUp on My5SecondTimeout global socketIsOpen, socketTimedOut if not socketIsOpen then put true into socketTimedOut end if end My5SecondTimeout on mySocketOpenMsg theParams global theIp, socketIsOpen put true into socketIsOpen write GET / HTTP/1.0 numToChar(13) numToChar(10) numToChar(13) numToChar(10) to socket theIp read from socket theIp for 50 with message mySocketReadDoneMsg end mySocketOpenMsg on mySocketReadDoneMsg socketId, theData global theIp close socket theIp answer read done: socketId theData end mySocketReadDoneMsg Web Photos Pro: Software for Photo Bloggers and Other Photo Power Users See us on the web at http://www.webphotospro.com/ On Jan 31, 2005, at 1:16 AM, [EMAIL PROTECTED] wrote: From: Sarah Reichelt [EMAIL PROTECTED] Subject: Re: Socket timeout not working with libUrl To: How to use Revolution use-revolution@lists.runrev.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=US-ASCII; format=flowed My product pings the Web Photos Pro website to look for new versions. This works great when the computer the product's running on is connected to the internet, but it hangs for 60 seconds when there's no net connection. My code looks like this: set the socketTimeoutInterval to 5000 put URL (getPhotoAlbumUrl() downloads/version_info.php) into newVersion Is there any way I can force a timeout after 5 seconds? Should I be using a non-blocking URL request? Should I be attempting to open a socket directly to do an initial am I connected to the internet? request, before making the URL request? Hi Frank, I would definitely use a non-blocking request, so the user won't even notice if it is trying failing. Try something like: set the socketTimeoutInterval to 5000 put (getPhotoAlbumUrl() downloads/version_info.php) into tURL load tURL with message gotVersion Then you need a gotVersion handler in the same object: on gotVersion put URL (getPhotoAlbumUrl() downloads/version_info.php) into newVersion -- check newVersion do the usual stuff end gotVersion Hope this helps, Sarah ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Socket timeout not working with libUrl
Frank Leahy wrote: After a lot of testing on Mac OS X, I've found that the problem I was having appears to be due to the way that Mac OS X does DNS lookups. Whether or not it's a RunRev bug as well is hard to tell, but I think it might be. Here's some sample code I wrote. This code sends a My5SecondTimeout message to itself, opens a socket, makes an HTTP GET request, waits for the response, and closes the socket. (Note: I had to use this My5SecondTimeout message because setting the socketTimeoutInterval doesn't seem to work). When you run this script and you're not connected to the internet here's what happens: 1) If I open the socket with an ip address, e.g. 64.125.128.80, my 5 second timer will fire, and I can close the socket and exit from the routine. 2) If I open the socket with a domain address, e.g. www.webphotospro.com, Mac OS X does a DNS lookup, puts up the rainbow rotating color cursor, and hangs until the DNS lookup fails. On my machine this takes 60 seconds (apparently it's dependent on how many dns servers you have listed). I'm guessing this is a RunRev bug, but I can't be sure. Basically RunRev hangs for 60 seconds while the DNS lookup takes place during the open socket call -- it doesn't send a socket timeout, and it doesn't the My5SecondTimeout message either. Can confirm this? Yes. you may have missed the email I sent earlier in this thread, re bug 2117 Engine blocks on DNS query Take a look at that bug report for more details. You can check for dnsservers - which will prevent the problem occurring in most cases, but there are still some cases where it will fail. -- Alex. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.7.6 - Release Date: 27/01/2005 ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Socket timeout not working with libUrl
Alex Tweedly wrote: When you run this script and you're not connected to the internet here's what happens: 1) If I open the socket with an ip address, e.g. 64.125.128.80, my 5 second timer will fire, and I can close the socket and exit from the routine. 2) If I open the socket with a domain address, e.g. www.webphotospro.com, Mac OS X does a DNS lookup, puts up the rainbow rotating color cursor, and hangs until the DNS lookup fails. On my machine this takes 60 seconds (apparently it's dependent on how many dns servers you have listed). I'm guessing this is a RunRev bug, but I can't be sure. Basically RunRev hangs for 60 seconds while the DNS lookup takes place during the open socket call -- it doesn't send a socket timeout, and it doesn't the My5SecondTimeout message either. Can confirm this? Yes. you may have missed the email I sent earlier in this thread, re bug 2117 Engine blocks on DNS query Take a look at that bug report for more details. You can check for dnsservers - which will prevent the problem occurring in most cases, but there are still some cases where it will fail. Unfortunately, BZ 2117 is currently being treated as a problem with RevOnline, rather than dealing with the fundamental problem of there being no way to query DNS without the risk of blocking for 40-120 seconds (or longer). Your experiments above prove that it is a fundamental problem, applying even to the non-blocking parts of libURL. Since BZ 2117 has been closed once already as can't be fixed, you may want to open a Bugzilla report to record the general problem, and simply mention 2117 as a special case of it. Even though it can't be fixed in the normal case (of, e.g., put URL ...) it can easily be provided as a non-blocking function, for use within non-blocking functions such as libURL, or revonline checks. In the meantime, there is a work-around - but it's pretty ugly . 1. write a shell script which does a ping to the machine you need to talk to, and saves its results to a log file. In my case, I created a file calledC:\MYPING.BATwhich contains ping www.tweedly.net c:\ping.txt (of course, you could create this dynamically, so as to handle any target machine). 2. In your app, launch this shell script then start a timer to check for the existence of the log file, and then check the results local lStart on mouseUp delete file C:/ping.txt set hideconsolewindows to true -- Win only put the seconds into lStart launch C:/myping.bat send tryNow to me in 5 seconds end mouseUp on tryNow local tFile put trying (the seconds - lStart) cr after field lockedField if there is a file C:/ping.txt then put URL file:c:/ping.txt into tFile filter tFile with *Reply* if the number of lines in tFile 0 then put success word 3 of line 1 of tFile cr after field lockedField exit tryNow end if end if if (the seconds - lStart) 80 then put failure after 80 secs cr after field lockedField else send tryNow to me in 5 seconds end if end tryNow 3. handle the minor variants needed for each platform (note - tested in my situation where I regularly encounter the problem you described. While I can't think of other circumstances where I would expect this to fail, I haven't done extensive testing of other scenarios). Or, alternatively, . instead of using www.webphotospro.com, use the hard-wired IP address; when that fails, use another hard-wired address to check for the presence of an Internet connection - and only then try again using the hostname (and store the IP address used). This last (blocking) case will only happen when your web site address has changed, and the user has an internet connection, but his DNS servers are either dead or unreachable - which is going to be very rare for any reasonable ISP. -- Alex. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.7.6 - Release Date: 27/01/2005 ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Socket timeout not working with libUrl
2) If I open the socket with a domain address, e.g. www.webphotospro.com, Mac OS X does a DNS lookup, puts up the rainbow rotating color cursor, and hangs until the DNS lookup fails. On my machine this takes 60 seconds (apparently it's dependent on how many dns servers you have listed). What happens if you try: hostNameToAddress(www.webphotospro.com) and use the result of that as the address for opening the socket? In my tests, this takes about 4 seconds the first time it is called if I am connected (which is long enough for the SPOD to appear). When I am disconnected, it fails instantly and return empty. Sarah ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Socket timeout not working with libUrl
Sarah Reichelt wrote:
2) If I open the socket with a domain address, e.g.
www.webphotospro.com, Mac OS X does a DNS lookup, puts up the rainbow
rotating color cursor, and hangs until the DNS lookup fails. On my
machine this takes 60 seconds (apparently it's dependent on how many
dns servers you have listed).
What happens if you try:
hostNameToAddress(www.webphotospro.com)
and use the result of that as the address for opening the socket?
In my tests, this takes about 4 seconds the first time it is called if
I am connected (which is long enough for the SPOD to appear). When I
am disconnected, it fails instantly and return empty.
It depends how you are connected.
If you do it on a machine directly connected to the Internet (e.g. my
laptop dialled into my ISP), then it will fail immediately (because it
knows the DNS server (obtained in this case by PPP negotiation) is
unreachable).
If you do this on a host which is connected to a LAN and (has been)
using a router attached to the LAN to connect, and the router (and/or
NAT box) has been configured (e.g. through DHCP) as the DNS server for
the host, and the router has lost its Internet connection, THEN it will
block for 15-120 seconds before failing. (example - my laptop, connected
through another PG running Win Internet Connection Sharing to a dial-up
line).
{Note - if you're testing this, remember the address will be kept in the
router's DNS resolver cache, so after any successful attempt, you need
to either wait or change the host name you are looking up - that just
caught me out when I tried this in preparation to send this email :-].
No doubt there are other circumstances where it would similarly fail
(e.g. maybe the case of a router hop between the host and the DNS
router/server, and the router-to-router link was down - but I haven't
test that one yet; it would depend on whether the intermediate router
was proxying DHCP or sub-leasing - and I suspect there are too many
variants to be worth getting into them).
The engine can't return a response to the hostnametoaddress query until
it gets a response from the DNS server (or the query times out), so it
simply blocks until the time-out. That's probably reasonable (or at
least unavoidable) for a blocking call like hostNameToAddress, but there
needs to be a non-blocking version of it, for use in non-blocking libURL
and any other action which is not user-triggered (or even to make the
user-interruptable).
-- Alex.
--
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Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 265.7.6 - Release Date: 27/01/2005
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Re: Socket timeout not working with libUrl
My product pings the Web Photos Pro website to look for new versions. This works great when the computer the product's running on is connected to the internet, but it hangs for 60 seconds when there's no net connection. My code looks like this: set the socketTimeoutInterval to 5000 put URL (getPhotoAlbumUrl() downloads/version_info.php) into newVersion Is there any way I can force a timeout after 5 seconds? Should I be using a non-blocking URL request? Should I be attempting to open a socket directly to do an initial am I connected to the internet? request, before making the URL request? Hi Frank, I would definitely use a non-blocking request, so the user won't even notice if it is trying failing. Try something like: set the socketTimeoutInterval to 5000 put (getPhotoAlbumUrl() downloads/version_info.php) into tURL load tURL with message gotVersion Then you need a gotVersion handler in the same object: on gotVersion put URL (getPhotoAlbumUrl() downloads/version_info.php) into newVersion -- check newVersion do the usual stuff end gotVersion Hope this helps, Sarah ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Socket timeout not working with libUrl
Hi, My product pings the Web Photos Pro website to look for new versions. This works great when the computer the product's running on is connected to the internet, but it hangs for 60 seconds when there's no net connection. My code looks like this: set the socketTimeoutInterval to 5000 put URL (getPhotoAlbumUrl() downloads/version_info.php) into newVersion Is there any way I can force a timeout after 5 seconds? Should I be using a non-blocking URL request? Should I be attempting to open a socket directly to do an initial am I connected to the internet? request, before making the URL request? Thanks in advance for any suggestions. Regards, -- Frank Web Photos Pro: Software for Photo Bloggers and Other Photo Power Users See us on the web at http://www.webphotospro.com/ ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Socket timeout not working with libUrl
Frank Leahy wrote: Hi, My product pings the Web Photos Pro website to look for new versions. This works great when the computer the product's running on is connected to the internet, but it hangs for 60 seconds when there's no net connection. My code looks like this: set the socketTimeoutInterval to 5000 put URL (getPhotoAlbumUrl() downloads/version_info.php) into newVersion Is there any way I can force a timeout after 5 seconds? Should I be using a non-blocking URL request? Should I be attempting to open a socket directly to do an initial am I connected to the internet? request, before making the URL request? Frank, it may depend on how the computer has no internet connection. Normally if there is no connection at all, it will fail immediately. I ran into a problem (with Revonline) that if the computer has a working connection to a router or other connecting machine, then it can fail. See Bugzilla 2117 for some more info and a hint of a possible workaround from Mark. I think you could also use a non-blocking URL request, if that was easier. -- Alex. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.7.6 - Release Date: 27/01/2005 ___ use-revolution mailing list use-revolution@lists.runrev.com http://lists.runrev.com/mailman/listinfo/use-revolution
