empty pages with `404 Not Found` during deployment about opengrok

[vladak]

My wild guess: the 404 happens while Tomcat is deploying new application. I'd sugest trying to find out Tomcat specific problems as I believe this is not OpenGrok specific.

E.g. http://stackoverflow.com/questions/15772419/avoid-temporary-404-errors-during-deployment-with-tomcat

PS: greetz to fellow OpenBSD user !

[cnst]

Wow, Google does work very nicely -- I've created that question on StackOverflow just a couple of hours ago, and here you are, already referencing it!

Someone on SO suggests that tomcat7 has a feature called Parallel Deployments, but the concept sounds sketchy, and might be incompatible with OpenGrok due to the listening TCP socket for configuration updates.

Perhaps some other servers implement this in a more robust and certain way?

[vladak]

Time to try Weblogic or similar I guess :-)

[vladak]

My knowledge about Java application servers is very limited but I am not sure this is actually solvable within single instance given the webapp needs to be undeployed and deployed again.

The solution might be to run 2 application servers in clustered configuration (with a smart load balancer in front of them ?) and switch whenever webapp redeploy needs to be done. The setup with 2 app servers and single indexer was recently disussed on the mailing list so more clues are there.

Thinking of this further it's not clear what is the use case. If 404 error which probably happens in very small time frame is an issue then the whole server is probably running stable version of the OS. On the instance I am taking care of we run long term support version of Solaris 11 with only occassional patching (the reboots to new boot environment are usually quick thanks to fastreboot skipping BIOS/PROM/controller setup and only switching kernels) and the same goes for OpenGrok which is running there (redeploy is relatively quick as the machine is pretty beefed up but anyway there has been only a handful of redeploys over many months).

[vladak]

Not sure if more value can be added to this discussion; it does not seem to be OpenGrok specific. Also it duplicates the one on stackoverflow, closing.