Re: [PHP] Re: Is gethostbyaddr() slow?
kalinga wrote: On 8/4/05, Kristen G. Thorson [EMAIL PROTECTED] wrote: kalinga wrote: if you are quering a external host, the bad network conditions may cause delay in results. if your server is connected to a heavily loaded hub/ cheap switch, or the target hosts DNS servers are poorly configured/ slow in responce it adds further delay to your result. try dig/ nslookup on your server for the target hostname/address, you may experience the same delay as with the php function. Thanks for the reply. The problem I had - and that I was trying to briefly describe - is not quite explained by slow DNS lookup, at least not so far. I have one script, run on the same machine: takes less than 1 second on CLI: # php gethostbyname.php Content-type: text/html X-Powered-By: PHP/4.3.2 gethostbyname(www.imakenews.com) took 0.0010 s and resolved to 208.254.39.65br gethostbyname(rssnewsapps.ziffdavis.com) took 0.0005 s and resolved to 63.87.252.162br gethostbyname(itpapers.zdnet.com) took 0.1922 s and resolved to 216.239.113.159br gethostbyname(rssnewsapps.ziffdavis.com) took 0.0005 s and resolved to 63.87.252.162br Running CLI again, host names are apparently cached, because then they all return in .0005 seconds. takes 20 seconds under Apache 2.0.46: gethostbyname(www.imakenews.com) took 5.0071 s and resolved to 208.254.39.65 gethostbyname(rssnewsapps.ziffdavis.com) took 5.0099 s and resolved to 63.87.252.162 gethostbyname(itpapers.zdnet.com) took 5.0097 s and resolved to 216.239.113.159 gethostbyname(rssnewsapps.ziffdavis.com) took 5.0099 s and resolved to 63.87.252.162 This will happen consistently, with less than 1/100 s variation in time for each lookup. Any DNS lookup tools are perfectly fast when run from the command line. Also, other machines in the same subnet, using the same DNS servers, using 99% same apache config files (I diff'ed 'em) run just as fast under same apache/php version as they do command line. It's hard to imagine what external DNS problem could exist that would affect only one of our servers, and on that one, only apache/php and nothing command line. Something else is going on, but my initial tries of downgrading/upgrading both php and apache haven't made a different yet. Perhaps you have another suggestion? could you please mention the environment, i mean, the os, and the versions of php? is it binary install or a compile? All binaries - RH-packaged rpms. Working version (takes 1 second for each gethostbyname() call under CLI and under apache): # rpm -qa | grep php php-odbc-4.3.2-23.ent php-imap-4.3.2-23.ent php-pgsql-4.3.2-23.ent php-4.3.2-23.ent php-ldap-4.3.2-23.ent php-mysql-4.3.2-23.ent # rpm -qa | grep httpd httpd-2.0.46-46.ent redhat-config-httpd-1.1.0-4.30.2 httpd-devel-2.0.46-46.ent # uname -r -o -i -s Linux 2.4.21-4.ELsmp i386 GNU/Linux Not working (takes 5 seconds for each gethostbyname() call under apache, but 1 second under CLI): # rpm -qa | grep php php-imap-4.3.2-23.ent php-4.3.2-23.ent php-odbc-4.3.2-23.ent php-mysql-4.3.2-23.ent php-ldap-4.3.2-23.ent php-pgsql-4.3.2-23.ent # rpm -qa | grep httpd httpd-2.0.46-46.ent redhat-config-httpd-1.1.0-4.30.2 httpd-devel-2.0.46-46.ent # uname -r -o -i -s Linux 2.4.21-4.ELsmp i386 GNU/Linux The function returns correctly, but it takes about 5 seconds every time. After I run the script the first time on the not working machine, it looks like the names are cached for the CLI, as they tend to take only .0005 seconds to resolve. Thanks for the help. kgt
[PHP] Re: Is gethostbyaddr() slow?
On 8/4/05, Kristen G. Thorson [EMAIL PROTECTED] wrote: I can say from personal experience that gethostbyaddr() and gethostbyname() can seem almost randomly slow, depending on machine, OS, software, who knows. I'm not smart enough to figure out the reason why it can vary so much on machines with nearly the same configuration, but I can tell you that it works perfectly fast most of the time. Then there's that other 5% where something makes it slow as molasses. I have two machines that are so similar it's not funny, but gethostbyname() takes 1/10 s on one, and 5 s on the other. I have yet to figure out what's the difference between them that causing this. kgt Dotan Cohen wrote: Hi all, I just discovered the gethostbyaddr() function. By reading the user contributed notes, I get the impression that either this function may cause performance problems, or a user-contributed function based upon it may be slow. So, is gethostbyaddr() slow? Is it dangerous? Thanks! Dotan Cohen http://lyricslist.com/lyrics/artist_albums/56/bangles.php The Bangles Song Lyrics -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Re: Is gethostbyaddr() slow?
On 8/4/05, kalinga [EMAIL PROTECTED] wrote: On 8/4/05, Kristen G. Thorson [EMAIL PROTECTED] wrote: I can say from personal experience that gethostbyaddr() and gethostbyname() can seem almost randomly slow, depending on machine, OS, software, who knows. I'm not smart enough to figure out the reason why it can vary so much on machines with nearly the same configuration, but I can tell you that it works perfectly fast most of the time. Then there's that other 5% where something makes it slow as molasses. I have two machines that are so similar it's not funny, but gethostbyname() takes 1/10 s on one, and 5 s on the other. I have yet to figure out what's the difference between them that causing this. if you are quering a external host, the bad network conditions may cause delay in results. if your server is connected to a heavily loaded hub/ cheap switch, or the target hosts DNS servers are poorly configured/ slow in responce it adds further delay to your result. try dig/ nslookup on your server for the target hostname/address, you may experience the same delay as with the php function. ~viraj. kgt Dotan Cohen wrote: Hi all, I just discovered the gethostbyaddr() function. By reading the user contributed notes, I get the impression that either this function may cause performance problems, or a user-contributed function based upon it may be slow. So, is gethostbyaddr() slow? Is it dangerous? Thanks! Dotan Cohen http://lyricslist.com/lyrics/artist_albums/56/bangles.php The Bangles Song Lyrics -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Re: Is gethostbyaddr() slow?
i missed another keypoint.. if you are running unix/linux server, you need to have a properly setup resolv.conf or if you experience a slowness while you quering your own domains, check whether you DNS servers are providing authoritative answers to your domains. ~viraj. On 8/4/05, kalinga [EMAIL PROTECTED] wrote: On 8/4/05, kalinga [EMAIL PROTECTED] wrote: On 8/4/05, Kristen G. Thorson [EMAIL PROTECTED] wrote: I can say from personal experience that gethostbyaddr() and gethostbyname() can seem almost randomly slow, depending on machine, OS, software, who knows. I'm not smart enough to figure out the reason why it can vary so much on machines with nearly the same configuration, but I can tell you that it works perfectly fast most of the time. Then there's that other 5% where something makes it slow as molasses. I have two machines that are so similar it's not funny, but gethostbyname() takes 1/10 s on one, and 5 s on the other. I have yet to figure out what's the difference between them that causing this. if you are quering a external host, the bad network conditions may cause delay in results. if your server is connected to a heavily loaded hub/ cheap switch, or the target hosts DNS servers are poorly configured/ slow in responce it adds further delay to your result. try dig/ nslookup on your server for the target hostname/address, you may experience the same delay as with the php function. ~viraj. kgt Dotan Cohen wrote: Hi all, I just discovered the gethostbyaddr() function. By reading the user contributed notes, I get the impression that either this function may cause performance problems, or a user-contributed function based upon it may be slow. So, is gethostbyaddr() slow? Is it dangerous? Thanks! Dotan Cohen http://lyricslist.com/lyrics/artist_albums/56/bangles.php The Bangles Song Lyrics -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: Is gethostbyaddr() slow?
kalinga wrote: if you are quering a external host, the bad network conditions may cause delay in results. if your server is connected to a heavily loaded hub/ cheap switch, or the target hosts DNS servers are poorly configured/ slow in responce it adds further delay to your result. try dig/ nslookup on your server for the target hostname/address, you may experience the same delay as with the php function. Thanks for the reply. The problem I had - and that I was trying to briefly describe - is not quite explained by slow DNS lookup, at least not so far. I have one script, run on the same machine: takes less than 1 second on CLI: # php gethostbyname.php Content-type: text/html X-Powered-By: PHP/4.3.2 gethostbyname(www.imakenews.com) took 0.0010 s and resolved to 208.254.39.65br gethostbyname(rssnewsapps.ziffdavis.com) took 0.0005 s and resolved to 63.87.252.162br gethostbyname(itpapers.zdnet.com) took 0.1922 s and resolved to 216.239.113.159br gethostbyname(rssnewsapps.ziffdavis.com) took 0.0005 s and resolved to 63.87.252.162br Running CLI again, host names are apparently cached, because then they all return in .0005 seconds. takes 20 seconds under Apache 2.0.46: gethostbyname(www.imakenews.com) took 5.0071 s and resolved to 208.254.39.65 gethostbyname(rssnewsapps.ziffdavis.com) took 5.0099 s and resolved to 63.87.252.162 gethostbyname(itpapers.zdnet.com) took 5.0097 s and resolved to 216.239.113.159 gethostbyname(rssnewsapps.ziffdavis.com) took 5.0099 s and resolved to 63.87.252.162 This will happen consistently, with less than 1/100 s variation in time for each lookup. Any DNS lookup tools are perfectly fast when run from the command line. Also, other machines in the same subnet, using the same DNS servers, using 99% same apache config files (I diff'ed 'em) run just as fast under same apache/php version as they do command line. It's hard to imagine what external DNS problem could exist that would affect only one of our servers, and on that one, only apache/php and nothing command line. Something else is going on, but my initial tries of downgrading/upgrading both php and apache haven't made a different yet. Perhaps you have another suggestion? Thanks, kgt -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Re: Is gethostbyaddr() slow?
On 8/4/05, Kristen G. Thorson [EMAIL PROTECTED] wrote: kalinga wrote: if you are quering a external host, the bad network conditions may cause delay in results. if your server is connected to a heavily loaded hub/ cheap switch, or the target hosts DNS servers are poorly configured/ slow in responce it adds further delay to your result. try dig/ nslookup on your server for the target hostname/address, you may experience the same delay as with the php function. Thanks for the reply. The problem I had - and that I was trying to briefly describe - is not quite explained by slow DNS lookup, at least not so far. I have one script, run on the same machine: takes less than 1 second on CLI: # php gethostbyname.php Content-type: text/html X-Powered-By: PHP/4.3.2 gethostbyname(www.imakenews.com) took 0.0010 s and resolved to 208.254.39.65br gethostbyname(rssnewsapps.ziffdavis.com) took 0.0005 s and resolved to 63.87.252.162br gethostbyname(itpapers.zdnet.com) took 0.1922 s and resolved to 216.239.113.159br gethostbyname(rssnewsapps.ziffdavis.com) took 0.0005 s and resolved to 63.87.252.162br Running CLI again, host names are apparently cached, because then they all return in .0005 seconds. takes 20 seconds under Apache 2.0.46: gethostbyname(www.imakenews.com) took 5.0071 s and resolved to 208.254.39.65 gethostbyname(rssnewsapps.ziffdavis.com) took 5.0099 s and resolved to 63.87.252.162 gethostbyname(itpapers.zdnet.com) took 5.0097 s and resolved to 216.239.113.159 gethostbyname(rssnewsapps.ziffdavis.com) took 5.0099 s and resolved to 63.87.252.162 This will happen consistently, with less than 1/100 s variation in time for each lookup. Any DNS lookup tools are perfectly fast when run from the command line. Also, other machines in the same subnet, using the same DNS servers, using 99% same apache config files (I diff'ed 'em) run just as fast under same apache/php version as they do command line. It's hard to imagine what external DNS problem could exist that would affect only one of our servers, and on that one, only apache/php and nothing command line. Something else is going on, but my initial tries of downgrading/upgrading both php and apache haven't made a different yet. Perhaps you have another suggestion? could you please mention the environment, i mean, the os, and the versions of php? is it binary install or a compile? Thanks, kgt -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
