Questions[keep-alive](server)

Is there any way to create a custom log file, that allows to see which requests were handled in the same keep-alive session?

I'd like to create some logs and to estimate how often new sessions are created and what typical live times a keep alive session has in some given scenarios.

If possible I wouldn't like to create debug logs for this but just add one item more per log line for each request.

I have an api into which ill get quite a few requests in https. Since its restful, each time the api is sent , it requires a full ssl handshake. On enabling http-keepalive , the latency of the request is reduced greatly (first request takes same time, but subsequent requests are as fast as http).

Now, I was experimenting with amazon's elb (I will also use cloud front). My question is, how will keep alive work in the same setup , where the request coming from a client can be routed to different machines randomly ?
Or is it not possible at all to prevent an ssl handshake each time a request is made ?

We have IIS servers in Azure behind load balancer. Load balancer has unconfigurable timeout of 4 minutes after which inactive connection is killed.

We're trying to setup nginx as a reverse proxy to the IIS cluster described above. Everything works fine except nginx doesn't send keep alive messages to the server it opened connection to. So, if server takes more than 4 minutes to reply the connection is killed by the load balancer.

If a client (browser) connects to the load balancer directly, it sends TCP keep alive messages and all is good. If client connects to nginx, it sends keep alive to nginx and all is good with connection to nginx. But no keep alive messages between nginx and load balancer, so eventually connection dies.

so_keepalive option seems to be related to the TCP keep alive for connections opened to nginx from client (browser).

We tried other reverse proxies (IIS ARR proxy, haproxy) and always ran into the same issue.

We can't configure load balancer (outside of our control). How could we configure either linux with nginx, nginx, or IIS behind load balancer (to which nginx connects) to get them to send keep alive messages to keep connection open?

How do I dynamically check/list a particular Apache configuration directive? I know that this can be checked manually from httpd.conf file, but is there any other way this can be confirmed/found from a running Apache server process?

For example: In my case, I was checking for KeepAlive configuration directive. I even checked with the command /usr/local/apache2/bin/apachectl -h, but I don't find it here.

We're currently using a hardware load balancer, which then goes to Apache and that then goes to Tomcat 5.5 via the AJP connector.

We've decided to dump apache for various reasons - In our current system it doesnt provide any advantage.

However when I look at the headers sent when we do this, the "Keep-Alive: timeout=15 max=96" header doesnt get sent when you use the tomcat http connector

Interestingly, i can find no documentiation on "keepalivetimeout" for tomcat5.5, but i can for tomcat6. But neither can i find evidence that tomcat5.5 doesnt support this setting.

here's my connector:

<Connector port="8090" maxHttpHeaderSize="8192"
               maxThreads="400" minSpareThreads="150" maxSpareThreads="300"
               enableLookups="false"
               connectionTimeout="2" maxKeepAliveRequests="400" disableUploadTimeout="true" />

So; Is there any way I can specify the keepalive timeout if we use the http connector with tomcat 5.5, and force this header entry to be sent?

Just to be clear - the exact header entry i see back from the server is this with apache:

Keep-Alive: timeout=2, max=100

But nothing from tomcat/coyote.

I've looked at this some more, and I dont think the Keep-Alive header entry really matters. The problem seems to be that keep-alives are simply not supported in tomcat 5.5 http connector? They do seem to work in tomcat6 (+java 6).

Thanks, Dan