Real World Performance Drupal
First ask questions about what is slow and take notes on what they say.
Define goals:
Goal 800 ms latency 50/50 logged in users
Step away from the client, and assume they lied to us and that they have never been to the site.
Step 1 - you need a net console like Firebug
Take some notes on what the page times are like
front page - 8 seconds
gallery - 23 seconds
article - 12 seconds
favorities - 13 seconds
It is temping to turn on devel and see what sql query is slow, but don't stay at the overview level.
Display the query time,
Display the query log
Go back and display the front page
pt-query-digest
Use the slow log tool kit pt-query-digest just point it to a slow log.
Set the sloq query time to 1 second
Copy the text of the top 3 slow queries
Viewslightpager module will remove the count for the pager
Seperate a combined view into two seperate views
Xdebug
Now use Xdebug to check PHP
Just add it to web root
Try to connect to memcache with telnet and the port, if you cannot connect.
Check to see if memcache is running, yes.
Is the firewall running, yes but none of the addresses match memcache
http://localhost:888?xdebug_profile
http://localhost:888 my web site
Varnish
The client is happy with authenticated users, but not happy with annonomus users.
Enable Drupal 7 to use varnish
vi sites/default/settings.php
edit the cache from false to true
cd /etc/varnish copy this from 4 kitchens web site
vi default.vcl
look at set req.http.Cookie = regsuball(...)
change apache listen to 8080
start varish
varnishlog use this to see if we get hits