I guess Web Applications is like Stack Overflow, but for web applications. Why is there Server Fault and Pro Webmasters? Is https://webmasters.stackexchange.com/ somewhere between https://serverfault.com/ and https://webapps.stackexchange.com/?
Troubleshooting server related stuff is just a small subset of the on topic scope at Webmasters. Webmasters is for questions related to the day to day task of maintaining a web site, and everything that doing so entails. So yes, a question regarding some kind of web server configuration is on topic there. A common question would be something
If you're building out your own server farm and have lots of questions about how to plan the infrastructure and connect all of those moving pieces together, your question should go to Server Fault. If you're having trouble getting OSQA working on DreamHost, it's probably:
- On topic for Webmasters if others will benefit from it
- On topic for DreamHost's support system if your problem is really localized, or is too complex to be answered in a Q&A format
There's also a bit of overlap with the UNIX/Linux sites, since naturally webmasters will also have questions regarding how to do certain things. It just comes down to "What site focuses the most on the core of the problem I'm having?" If the core of the problem is about running and maintaining a web site, ask it on Webmasters. If you just can't get Apache working, try Server Fault. If you want to know how to do something via shell on your VPS, perhaps try the Unix/Linux / Ubuntu sites.
While the same question might be technically on topic for all four, it comes down to asking it on the site that you think best fits the problem.
- webapps: how to use certain web applications such as gmail, google docs, etc.
- webmasters: how to maintain websites, like managing domain names, SSL, web farm, load balancing, etc.
- dba: how to maintain database servers, for example how to tune index, partitioning tables, etc.
- serverfault: how manage servers, networks, PCs in workplace, for example active directory, mail server, FTP server, etc.