Hi, I need the help of the community. I am not succeding in making our app faster. The problem is the Time to first Byte (TTFB). It is always more than one second which is much to much. We reduced the problem to a *problem between apache and pharo/seaside*. For this, I have a test application which only renders "hello World". So I am sure it is not my code, my database, my css, my js, my ssl.... :-) I optimized and learned a lot for my app, but it did not solve the TTFB problem, which costs 1 additional sec for each click of the user which is inaceptable. Please follow this tests to see the problem: ===>>> Test 1: test.html without Pharo/seaside https://tools.keycdn.com/performance?url=http://app.spesenfuchs.de/test.html TTFB in Frankfurt below 10 ms -> this proves that the server and configuration is fast. ===>>> Test 2: hello world, simple seaside page https://tools.keycdn.com/performance?url=app.spesenfuchs.de/hello TTFB in Frankfurt more than 1 second! -> this proves that it is not my application :-) it is only a hello world seaside page... ===>>> Test 3: my login page https://tools.keycdn.com/performance?url=app.spesenfuchs.de/rka TTFB in Frankfurt more than 1 second! (alternative: enter the urls into https://gtmetrix.com/) In Apache, we enabled tracing of the rewrite and this tells me (i assume), that apache makes the rewrite very fast, within the same millisecond :-) [Thu Jan 05 12:14:35.243400 2017] [rewrite:trace2] [pid 1288:tid 1692] mod_rewrite.c(477): [client 91.89.219.232:52272] 91.89.219.232 - - [app.spesenfuchs.de/sid#66c848][rid#20bc4c8/initial] init rewrite engine with requested uri /hello [Thu Jan 05 12:14:35.243400 2017] [rewrite:trace3] [pid 1288:tid 1692] mod_rewrite.c(477): [client 91.89.219.232:52272] 91.89.219.232 - - [app.spesenfuchs.de/sid#66c848][rid#20bc4c8/initial] applying pattern '^/rka(.*)$' to uri '/hello' [Thu Jan 05 12:14:35.243400 2017] [rewrite:trace3] [pid 1288:tid 1692] mod_rewrite.c(477): [client 91.89.219.232:52272] 91.89.219.232 - - [app.spesenfuchs.de/sid#66c848][rid#20bc4c8/initial] applying pattern '^/hello(.*)$' to uri '/hello' [Thu Jan 05 12:14:35.243400 2017] [rewrite:trace2] [pid 1288:tid 1692] mod_rewrite.c(477): [client 91.89.219.232:52272] 91.89.219.232 - - [app.spesenfuchs.de/sid#66c848][rid#20bc4c8/initial] rewrite '/hello' -> 'http://localhost:8085/HelloWorld/' [Thu Jan 05 12:14:35.243400 2017] [rewrite:trace2] [pid 1288:tid 1692] mod_rewrite.c(477): [client 91.89.219.232:52272] 91.89.219.232 - - [app.spesenfuchs.de/sid#66c848][rid#20bc4c8/initial] forcing proxy-throughput with http://localhost:8085/HelloWorld/ [Thu Jan 05 12:14:35.243400 2017] [rewrite:trace1] [pid 1288:tid 1692] mod_rewrite.c(477): [client 91.89.219.232:52272] 91.89.219.232 - - [app.spesenfuchs.de/sid#66c848][rid#20bc4c8/initial] go-ahead with proxy request proxy:http://localhost:8085/HelloWorld/ [OK] So, I assume that there is problem between Apache and Seaside.... My questiond are: what can I do to find the bottleneck? what is the reason that is so slow? your help is very appreciated because I have run out of ideas what it could be and I was investigating it several days now. Concerning the system: The server is at Amazon ec2 windows Server 2009 R2 SP1 The Apache version is 2.4.23 The configuration of the apache is like this (as described in the seaside book http://book.seaside.st/book/advanced/deployment/deployment-apache/configure-...) <VirtualHost *:80> ProxyPreserveHost On ServerName app.spesenfuchs.de RewriteEngine On <Directory "C:\xampp\htdocs"> Require all granted </Directory> DocumentRoot "C:\xampp\htdocs" RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f RewriteRule ^/rka(.*)$ http://localhost:8085/RKA/$1 [proxy,last] RewriteRule ^/hello(.*)$ http://localhost:8085/HelloWorld/$1 [proxy,last] </VirtualHost> -- View this message in context: http://forum.world.st/TTFB-Apache-Seaside-Performance-Problem-tp4928839.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.