Web Hosting Talk : Web Hosting Main Forums : Dedicated Server : Have a little problem with my server

[technichristian]

Hi all,

I have a server with server.lu, that is running absolutely fine except for this one problem for which I am unable to pinpoint the cause.

My domain on that server is http://twin-india.org

The main page loads fast. However after that, any request takes about 8 - 10 seconds to be fulfilled. That is the waiting for server message is displayed in the browser for about 8 - 10 seconds and then bang the page is displayed.

The server is running nginx.

Loading the server.lu page and clicking on links there, all loads fast (in about a max of 2 - 3 seconds).

Here is my traceroute to my server twin-india.org

tcptraceroute twin-india.org

traceroute to twin-india.org (212.117.178.2), 30 hops max, 40 byte packets
1 192.168.1.1 (192.168.1.1) 0.957 ms 1.449 ms 1.931 ms
2 ABTS-North-Static-002.127.176.122.airtelbroadband.in (122.176.127.2) 17.225 ms 17.557 ms 17.998 ms
3 125.19.38.169 (125.19.38.169) 19.558 ms 22.000 ms 24.721 ms
4 203.101.100.169 (203.101.100.169) 239.576 ms 243.502 ms 244.711 ms
5 203.101.95.129 (203.101.95.129) 293.514 ms 294.023 ms 295.191 ms
6 AES-Static-137.36.144.59.airtel.in (59.144.36.137) 252.017 ms 224.217 ms 226.327 ms
7 10g.linx.lon.as5577.net (195.66.225.90) 237.613 ms 234.984 ms 236.315 ms
8 40g.lon-lxb.as5577.net (83.243.12.5) 246.815 ms 240.316 ms 242.637 ms
9 host.technichristian.net (212.117.178.2) 247.806 ms 242.244 ms 247.342 ms

----
The traceroute to server.lu:

traceroute server.lu
traceroute to server.lu (195.26.4.101), 30 hops max, 40 byte packets
1 192.168.1.1 (192.168.1.1) 1.073 ms 1.574 ms 2.138 ms
2 ABTS-North-Static-002.127.176.122.airtelbroadband.in (122.176.127.2) 13.958 ms 15.849 ms 18.256 ms
3 125.19.38.165 (125.19.38.165) 20.359 ms 22.189 ms 24.162 ms
4 203.101.100.173 (203.101.100.173) 242.409 ms 244.186 ms 246.137 ms
5 203.101.100.222 (203.101.100.222) 249.404 ms 251.272 ms 253.198 ms
6 AES-Static-137.36.144.59.airtel.in (59.144.36.137) 254.671 ms 226.596 ms 227.520 ms
7 10g.linx.lon.as5577.net (195.66.225.90) 237.824 ms 240.910 ms 242.856 ms
8 40g.lon-lxb.as5577.net (83.243.12.5) 256.958 ms 258.355 ms 260.313 ms
9 server.lu (195.26.4.101) 261.420 ms 263.256 ms 266.710 ms
--------------

My other server at technichristian.net also responds fast [2 seconds max]. It is also configured almost identically as twin-india.org, the only difference being that twin-india.org runs drupal and the other runs wordpress.

What am I doing wrong? How can I speed up the response?

Thanks and God bless you all

Michael

[e-Sensibility]

Enabling caching on your drupal site will speed things up.

The reason that your front page to the drupal site loads quickly while sub-pages don't may be that your browser has the front page cached.

[technichristian]

Thanks e-sensibility. I do have caching enabled for both drupal as well as mysql.

Here are the mysql statistics from drupal:

SQL
Command counters
Variable Value Description
Com_select 1 The number of SELECT-statements.
Com_insert 0 The number of INSERT-statements.
Com_update 0 The number of UPDATE-statements.
Com_delete 0 The number of DELETE-statements.
Com_lock_tables 0 The number of table locks.
Com_unlock_tables 0 The number of table unlocks.

Query performance
Variable Value Description
Select_full_join 0 The number of joins without an index; should be zero.
Select_range_check 0 The number of joins without an index; should be zero.
Sort_scan 0 The number of sorts done without using an index; should be zero.
Table_locks_immediate 384479 The number of times a lock could be acquired immediately.
Table_locks_waited 65 The number of times the server had to wait for a lock.

Query cache information

The MySQL query cache can improve performance of your site by storing the result of queries. Then, if an identical query is received later, the MySQL server retrieves the result from the query cache rather than parsing and executing the statement again.

Variable Value Description
Qcache_queries_in_cache 25159 The number of queries in the query cache.
Qcache_hits 2306464 The number of times that MySQL found previous results in the cache.
Qcache_inserts 208784 The number of times that MySQL added a query to the cache (misses).
Qcache_lowmem_prunes 0 The number of times that MySQL had to remove queries from the cache because it ran out of memory. Ideally should be zero.

Anything amiss in this?

[technichristian]

Is anyone else experiencing a slightly long waiting time on the sub-pages?

[Vinayak_Sharma]

For me even the homepage was quite slow, browser was waiting and then the whole page displayed suddenly. Is compression on for the pages?

What's the average server load?

[tim2718281]

Originally Posted by technichristian

Is anyone else experiencing a slightly long waiting time on the sub-pages?

Yes, it is very slow. For example, the request

http://twin-india.org/index.php?q=taxonomy/term/2

took over 8 seconds.

And there were a further 19 requests in that page.

What's surprising is that those 19 requests were slow to refresh, even when nearly all the content was cached in the browser, and so the server merely sent a 304 (not modified) response.

So I can only think the server is severely overloaded ... without any information to go on, I'd suggest it might be paging heavily, and swapping processes in and out of RAM.

If that's correct, you might be able to speed things up quite a bit by reducing the number of processes running in parallel. Also check that the amount of RAM being used by SQL and Drupal is reasonable for the server configuration

Often you can speed things up a lot by specifying HTML "expires" headers for jpg, gif, css and js files and other files that do not change often. That will not only mean the browser does not have to wait for the 304 response for data it already has in its cache, it means the server does not have to handle the associated requests. As this can be done easily in the Apache configuration, it's worth doing.

   ExpiresActive On                  # enable expirations
   ExpiresByType text/gif M604800    # GIF documents are good for a
                                     # week from the time they were
                                     # changed

What you should see in Apache's access log is a reduction in the number of requests.

(This all assumes that users of the web site visit it multiple times in a week or so)

[technichristian]

Thanks Vinsar and Tim.

Here is the load:

uptime

09:35:30 up 1 day, 12:32, 1 user, load average: 0.13, 0.26, 0.29

Here is ps -e:

free -m
total used free shared buffers cached
Mem: 5939 1418 4520 0 104 890
-/+ buffers/cache: 424 5514
Swap: 4102 0 4102

Here is mysql configuration values:

# * Fine Tuning
#
key_buffer = 48M
max_allowed_packet = 32M
thread_stack = 512K
thread_cache_size = 12
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover = BACKUP
#max_connections = 100
table_cache = 256
#thread_concurrency = 10
#
# * Query Cache Configuration
#
query_cache_limit = 4M
query_cache_size = 100M

[mysqldump]
quick
quote-names
max_allowed_packet = 32M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completition

[isamchk]
key_buffer = 32M


Also in nginx:

worker_processes 4;

client_body_buffer_size 800k;
client_header_buffer_size 1000k;
client_max_body_size 1000k;
large_client_header_buffers 1000 100k;
client_body_timeout 5;

sendfile on;
keepalive_timeout 65;
tcp_nodelay on;
send_timeout 5;

gzip on;
gzip_buffers 100 800k;
gzip_comp_level 9;
gzip_http_version 1.0;

Also I have set memcached to consume 64 megs of RAM.

Any other thing I could try?

Also will a gigabit line help in this case?

Thanks.

[coolvserver]

Your server load looks ok to me. The load is not the reason for slow page.
Is the server behind a firewall?
Do you have a lot traffic to the site?

[coax]

http://s3.machinecode.org/images/twinindia.jpg

[tim2718281]

Originally Posted by coolvserver

Your server load looks ok to me. The load is not the reason for slow page.
Is the server behind a firewall?
Do you have a lot traffic to the site?

Viewing the page loading events using Firebug in Firefox, the initial request for index.php can take over 8 seconds.

I can't see what else to do except examine index,php to see what it's doing that is taking so long.

I wonder: could index.php be getting content from another server?

[technichristian]

Thank you all.

Tim, the index.php is the standard one that comes with drupal.

It does not reference any external sites.

I have tried the best to tune the server but still it takes at least 8 seconds to load a page.

Is nginx slow in loading php? Should I try apache?

Or do I need a gigabit line? The max users at any time does not exceed 200.

Thanks.

[tim2718281]

Originally Posted by technichristian

Thank you all.

Tim, the index.php is the standard one that comes with drupal.

It does not reference any external sites.

I have tried the best to tune the server but still it takes at least 8 seconds to load a page.

Is nginx slow in loading php? Should I try apache?

Or do I need a gigabit line? The max users at any time does not exceed 200.

Thanks.

1) I don't think the comms speed is the problem. Only about 2% of the 8 seconds is for transmitting data.

2) I had a look round for web pages referring to nginx, php, and drupal, and found this

http://drupal.org/node/110224

"So I've been getting stuck into making Drupal 4.7 (and 5.0) work with Nginx, which is a bit like Lighttpd except without the firehose-esque memory leaks you get with Lighty and actual web traffic busier than a trickle.

"This has worked for me for the last several days on (! NSFW !) cliterati.co.uk, which roars through about 30 HTTP requests per second. ..."

So I went to cliterati.co.uk - (which turns out to be a site discussing sex, by the way, so you have been warned) and I could not believe how slow it was! Slower than yours!

So on the face of it, I'd guess it's drupal that's slow. Probably you can speed it up by some kind of database tuning ... it can't possibly be normal for drupal sites to be that slow

You appreciate this is all guesswork; but you didn't mention setting a join buffer size; and you can log slow queries

join_buffer_size = 512K
log_slow_queries = /var/log/mysql/mysql-slow.log
long_query_time = 1

See the MySQL documentation for other parameters relation to log_slow_queries.

But if Drupal uses prepared SQL statements, they may not show in the slow query log.

[coax]

Did you try checking your modules and disabling to see?

[technichristian]

Thanks Tim. I did set the join buffer now. It does not seem to have made any difference though.

Thank you Coax. I only have the absolutely necessary modules enabled:-)

[technichristian]

And am not sure it is Drupal at fault.

http://samartha.info

This one opens and responds fast. True the traffic levels are different but still....

This one is hosted on leaseweb and uses Drupal.