I'm Kevin. I live in Salem, Mass with my wife and little boy and I build software.

So, I was doing some playing with Siege today which can be used to do regression testing and benchmarking on a webserver.

Install on RedHat was easy: $ yum install siege

Quick test of 100 concurrent users for 10 seconds randomly hitting the urls from url_list.txt (one URL per line): $ siege -c 100 -t 10s -f url_list.txt

The interesting thing was turning on normal caching in Drupal (no block caching because I'm using the node privacy byrole module). Check out the difference:

Before caching: SIEGE 2.66 Preparing 100 concurrent users for battle. The server is now under siege... Lifting the server siege.. done. Transactions: 27 hits Availability: 100.00 % Elapsed time: 9.77 secs Data transferred: 0.77 MB Response time: 5.56 secs Transaction rate: 2.76 trans/sec Throughput: 0.08 MB/sec Concurrency: 15.37 Successful transactions: 27 Failed transactions: 0 Longest transaction: 9.26 Shortest transaction: 0.00

After caching: SIEGE 2.66 Preparing 100 concurrent users for battle. The server is now under siege... Lifting the server siege.. done. Transactions: 179 hits Availability: 100.00 % Elapsed time: 10.27 secs Data transferred: 3.45 MB Response time: 4.67 secs Transaction rate: 17.43 trans/sec Throughput: 0.34 MB/sec Concurrency: 81.40 Successful transactions: 179 Failed transactions: 0 Longest transaction: 10.01 Shortest transaction: 3.65

Third time running after caching: SIEGE 2.66 Preparing 100 concurrent users for battle. The server is now under siege... Lifting the server siege.. done. Transactions: 1353 hits Availability: 100.00 % Elapsed time: 10.50 secs Data transferred: 18.73 MB Response time: 0.74 secs Transaction rate: 128.86 trans/sec Throughput: 1.78 MB/sec Concurrency: 95.98 Successful transactions: 1353 Failed transactions: 0 Longest transaction: 1.40 Shortest transaction: 0.03

I hit my max_clients limit with plenty of memory to spare the first run, but only had a concurrency of 15. However check out the difference in transactions after turning on caching. 27 before caching and 179 immediately after. Then 563 and 1353 after running a second and third time. Plus, the last run, I hit 95 concurrency!!

Now, Drupal caching isn't going to be as great for authenticated users, but for a site that has mostly anonymous visitors, the caching is pretty impressive. So, moral of the story, turn on normal caching when you install a new Drupal site :)

On a side note, you should also install the devel module and log queries - again quite impressive when you turn on caching.