I have six dedicated servers on a VPR. I use one of these as the Database server and the other five connects to that server to read the Database.
When I setup my scripts for the first time I used the external IP to connect to the DB server. Everything worked perfect for these weeks:
mysql_connect('174.xxx.xxx.xx', 'user', 'pass');
Since three days ago I finally received the internal IPs of my servers and now I use the internal IP of the DB server:
mysql_connect('10.0.0.1:3306', 'user', 'pass');
When I did this last change this my database started to collapse. Queries stuck on a bottleneck every 10 minutes. Here's an example:
40468 simon 10.0.0.7:47002 pkindigo_db Query 115 Locked update `captured` set hp_left = '79', status = 'normal', att1pp = '25', att2pp = '30', att3p
40523 simon 10.0.0.2:58080 pkindigo_db Query 115 Locked update `captured` set experience = '5120', level = '16', hp_left = '58', hp = '58', status =
... (tons of locked queries before) ...
As you may see table is locked since 115 seconds for a simple update... after some hours this ends on a "#1135 - Can't create a new thread (errno 13); if you are not out of available memory, you can consult the manual for a possible OS-dependent bug" and even some of my tables finally crashing.
I think that my Database stuck because of a DNS lookup delay. When I had this problem before using the external IPs, I added skip-name-resolve and the problem was fixed. But now with the internal IPs it seems that's not enough.
My MySQL server slowed down to a crawl a few days ago, and I finally fixed it by starting it without DNS lookups via "--skip-name-resolve".
I tested domain name resolution on the MySQL machine and it was able to return IPs from domains rather quickly, so I'm at a loss as to why DNS was the problem here? I am using "192.168.1.6" as the MySQL server's IP, in case that matters?
I have a couple of questions:Why is DNS resolution so slow when in the command line it's running normally?
Why does MySQL need to do DNS lookups at all? I don't see any log files that's converting IPs to host names or vice versa.
For some reason on a box I have, it takes 25 seconds from the time I hit enter for a usernames password for it to login via SSH. I am running CentOS 4.4
Is there something I can check to see why it is taking so long and/or fix this?
I host my site on webcity and have done for 6-7months. Most of the time, I publish my web and the changes appear virtually immediately.
Some weeks ago, the lag between publishing and appearing began to take hours. I advised webcity support and the next day back to normal.
Yesterday, it started again. I emailed webcity and their reposnse was - it's your cache. I rang webcity and again was advised - it's your cache (or something your ISP is doing).
I don't believe it is cache. I can refresh the page, close the browser, reboot the computer, clear all temp files (run CC Cleaner) - no difference.
I'm running Apache 2.4.4 Win32 on a Windows 2008 server. When trying to optimize a website I noticed a random reoccurring 2550ms delay in Time To First Byte. A file could have a TTFB of 200ms several times but suddenly it would get 2750ms. This could be a static file (image, html, js) or php. I've measured using ApacheBench (locally and remotely), webpagetest.org and bytecheck.com. After much trial and error I found the problem was with mod_rewrite. Disabling this and everything is fine.
I have setup a blank/new install with only basic config change (Listen, ServerRoot etc) to replicate result without anything else interfering. Following is the rewrite section I add to config.
Code: <IfModule mod_rewrite.c> RewriteEngine on RewriteRule (^/Pictures.*) /$1 [L] </IfModule>
After Apache has started I execute "ab http://my.example.com/Pictures/Thumbnails/tmb_400X400_FFFFFF_660.jpg" and always get the delay. If I execute again it's normal. If I wait at least 30 seconds I get the delay. Following is a section from error.log with trace8 logging.
Code: [Tue Mar 12 23:28:56.123519 2013] [rewrite:trace3] [pid 7624:tid 888] mod_rewrite.c(468): [client 69.x.y.90:36279] 69.x.y.90 - - [my.example.com/sid#42c748][rid#26df0d0/initial] applying pattern '(^/Pictures.*)' to uri '/Pictures/Thumbnails/tmb_400X400_FFFFFF_660.jpg'
[Code] ....
As you see from line 3 to line 4 the time skips 2550ms. When the TTFB is normal then the log is identical except time doesn't change from line 3 to line 4. If I delete the rewrite section in config then TTFB is always normal, no matter what.
When I testet on the live server the time for fully loaded increase from 3800-4000ms to 8500-10500ms when mod_rewrite is enabled. And that is about 30 requests (php+css+js+images). So the impact is significant.
What can this be? I'm having a hard time believing it's a bug. Isn't mod_rewrite used a lot? I'm running Ubuntu (linux) at home, I'm going to install Apache there and see if I get the same result.
VPS: Openvz, 512mb, 50gb hd, 10mbit shared located in Kansas.
Problem: After entering in my username / password I experience a 2-5 minute delay before the login is processed. I have tried logging in from 3 different ISP's (AT&T, Comcast, T-mobile via Blackberry), 1 webserver (ssh), and HyperVM's Java client. Each produces the same result.
Also, apps such as yum and traceroute produce the same long delays ranging from 2-5 minutes as though the vps locks up or the node has zero resources.
When I use the command center via HyperVM I receive the same long delays. Rebuilding the VPS does nothing. O/S has no affect.
Despite long discussions with the VPS staff they insist there are no problems on their end and that no one else is experiencing this problem. What gives?
I am using apache proxypass to proxy to 4 different ports (java/jsp applications) with the following configurations (for each):
<VirtualHost *:80> ProxyPreserveHost On ProxyRequests Off ServerName *****.org ProxyPass / http://*****.org:8080/ retry=0 ProxyPassReverse / http://*****.org:8080/ </VirtualHost>
Everything seems work fine until an awkward delay / connection timeout occurs. The web application hangs for about 5 to 15 seconds and starts working normally after that period. It's certainly not the application's issue because everything is fine when using IP address to access it.
When I enabled the debug log in apache, I found out that every time the server seems to hang, the following error appears in the apache error log and the number of apache child processes keep on increasing (ps aux | grep apache).
[Thu Apr 11 10:20:41 2013] [debug] proxy_util.c(1818): proxy: grabbed scoreboard slot 4 in child 13208 for worker proxy:reverse [Thu Apr 11 10:20:41 2013] [debug] proxy_util.c(1837): proxy: worker proxy:reverse already initialized [Thu Apr 11 10:20:41 2013] [debug] proxy_util.c(1934): proxy: initialized single connection worker 4 in child 13208 for (*) [Thu Apr 11 10:20:41 2013] [debug] proxy_util.c(1818): proxy: grabbed scoreboard slot 3 in child 13208 for worker http://*****.org:8080/ ..... Also, the access log (access.log) completely stops during that hang period.
This debug message keeps on repeating as long as Apache/web-application is not responding. The application starts to work normally after that duration and the number of apache child process decrease to the normal number.
Apache version : 2.2.16 (Debian) OS : Debian GNU/Linux 6.0 root@server:~# apache2 -V Server version: Apache/2.2.16 (Debian) Server built: Nov 30 2012 08:58:36
if I do a reverse lookup on my server's IP it returns a host assigned by the data center. So is this something I should even be managing too or is that always left up to the DC? I run my own DNS for the forward lookup zones.
Also just a technical question, when you do a reverse lookup, how does it know where to look to get the host? I'm not sure I fully understand how these work.
Somebody purchased a domain from a popular registrar. When you lookup the domain, it points to its own name servers (i.e. ns1.registrar.com and ns2.registrar.com), which means that it is hosted by them as well. correct?
this person is saying they bought their domain from the registrar, but they are hosted by company X. he says that he is pointing the ip address of his web site on company X to his registrar.
I want to know how serious following nameserver problem can be in reality: [url] ?
From DNS timing someone could conclude it's a slow hosting.
Can anyone explain above results "accurately" ? I still don't know what's "good" result in DNS timing: A or F?
The problem is that [url] loads slow (5-10 seconds on T1 connection), here's a speed test. I'm aware images and scripts contribute to slow site loading.
My question is: Beside removing some images from the Home page, is it any reason to change the hosting (regarding DNS tests).
Friend of mine asked me what "CURL named lookup issue resolved" means, he's got a CentOS 4 machine, with cPanel/WHM latest builds I tried recompiling apache and even cPanel at some point but no good..
I am having a problem. My server was able to ping google.com successfully before installing DirectAdmin.
However after installing DirectAdmin, I am no longer able to ping google.com anymore. I just get a host cannot be found error. This is the same with all other domains.
The /etc/resolv.conf is exactly the same, so I do not know the issue. I also have other servers using the same nameserver and are still able to ping and resolve successfully.
The main problem here is that exim no longer can send email as it cannot lookup the hostnames.
the error from exim is: R=lookuphost defer (-1): host lookup did not complete.
My VPS Config: centos with webmin mail program sendmail
Its a newly configured VPS have a problem with smtp realying through outlook and other smtp programs. When i use smtp on outlook it give following error:
The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'xxxxx@yahoo.com'. Subject 'Outlook', Account: 'Testing', Server: 'xxxx.com', Protocol: SMTP, Server Response: '550 5.7.1 <xxxxx@yahoo.com>... Relaying denied. IP name possibly forged [xx.xxx.xx.xxx]', Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79
I want to make outgoing authentication activate instead of allowing some iprange or domain for relaying through /etc/mail/access.
I'm having tons of problems trying to get reverse lookup working on my dns server. I've scoured the net and tried lots of methods but so far none work.
Forward lookup DNS is working perfect, but reverse lookup is completely broken.
db.44.80.212.67:
Code: $TTL 86400 ; Default TTL in secs(1 day) @ IN SOA ns1.capturetheprize.com. info.capturetheprize.com. (
2009072902; serial number YYMMDDNN 28800 ; Refresh 7200 ; Retry 864000 ; Expire 86400 ; Min TTL )
IN NS ns1.capturetheprize.com. IN NS ns1.mytempmail.com.
; Reverse lookups 44 IN PTR ns2.mytempmail.com. 44 IN PTR ns1.mytempmail.com. 44 IN PTR ns2.capturetheprize.com. 44 IN PTR ns1.capturetheprize.com. 44 IN PTR mail.mytempmail.com. 44 IN PTR mail.capturetheprize.com. 44 IN PTR stats.capturetheprize.com. 44 IN PTR secure.capturetheprize.com. named.conf
Code: zone "80.212.67.in-addr.arpa" IN { type master; file "etcdb.44.80.212.67"; allow-transfer { localhost; }; };
if its possible to change the reverse lookup, or at least i think thats what it is called.
I have 2 accounts on my CentOS, WHM/cPanel VPS and they are hosted on their own seperate IPs however when you do a lookup on one domain it also lists the other domain as being hosted on the server and vice-versa.
How do i change this so they appear like they are on different servers? Each one has their own nameservers which are on seperate IPs also.
Where am I sending e-mails from with the below settings:
(Is it mail.freesexdoor.com, www.freesexdoor.com, 64.85.161.123 or 64.85.161.124?)
My secondary question is: Is creating own reverse IP lookup to 64.85.161.124 possible and beneficial in my case? If so, what should I replace this SPF line with: freesexdoor.com. TXT "v=spf1 a mx ip4:64.85.161.123 ?all"?
I'm trying to improve freesexdoor.com's e-mail delivery ratio because hotmail and gmail deliver my PHP mailer's sent confirmation e-mails to the junk folder. I've done everything I can to improve the sent headers etc. so there's only one more possible way to improve it: (That I can think of). Freesexdoor.com is hosted on the same server as mitorahgames.com.
DirectAdmin control panel on CentOS 4.4.
My server's primary IP is: 64.85.161.123 My server's hostname is: server.mitorahgames.com
server.mitorahgames.com's Related DNS Settings: mailA64.85.161.123 server.mitorahgames.com.A64.85.161.123 server.mitorahgames.com.NSns1.mitorahgames.com. server.mitorahgames.com.NSns2.mitorahgames.com. mailMX10 123.161.85.64.in-addr.arpaPTRserver.mitorahgames.com. server.mitorahgames.com.TXT"v=spf1 a mx ip4:64.85.161.123 ?all"
freesexdoor.com's IP is: 64.85.161.124 freesexdoor.com's Related DNS Settings:
freesexdoor.com.A64.85.161.124 mailA64.85.161.124 mailMX10 freesexdoor.com.TXT"v=spf1 a mx ip4:64.85.161.123 ?all"
I'm by the way putting www.freesexdoor.com (PHP reported server name) to the Message ID: field in the e-mail headers. Would putting IP there perhaps work better? If so, which IP?
I have a windows 2000 server and I would like to configure two domain names, c.com and bnvsaj.c.com and requests to these domains should be forwarded to 192.168.0.1 and 192.168.0.2. How can I configure like this?
One of my customers uses Webmasters Tools from google , looking at what pages he have indexed by Googlebot, found that 180 pages are giving a "DNS lookup timeout" error, tried searching for help on google and the only thing that i found is " We received a timeout on DNS lookup."
DNS are ok, same as the zone file, everything is responding OK, I dont know what can be the issue.. ? any ideas ?
I regularly have DNS issues with some of my sites hosted with a specific host... At random sites, the urls done resolve and I get a DNS error. Just to find out that a few hours later it loads again without issues...
I always thought it had something to do with my ISP... My host says that there's nothing wrong with their DNS. However, I asked a few people now and it seems they're having DNS problems too sometimes when accessing the problematic urls...
