On Fri, Aug 17, 2012 at 9:47 AM, Tatsuhiko Miyagawa <miyag...@gmail.com>wrote:
> Now, with Server::Starter a "graceful" restart sends a SIGHUP -- I'm not
> clear if that's the same "graceful" apache uses where Apache waits for a
> child's connection to close before killing off that process.
> You have to convert the SIGHUP to SIGQUIT as in the Starman documentation
> so that Starman gracefully shuts down the current workers while
> Server::Starter launches the new set of the workers.
Right, because by default Server::Starter sends a TERM.
I intended to ask about the docs. The docs say:
... sending "QUIT" signal to the master process will gracefully shutdown
the workers (meaning the currently running requests will shut down once
the request is complete).
What does "request is complete" mean? Is that like Apache where it waits
for the socket to close on the worker? As in my case where a long running
keep-alive will keep the process busy until the connection is closed?
> That said, because of the problem you described, I strongly do not
> recommend enabling keep-alives between your frontend servers and Starman. I
> would say it's not even supported. (The documentation suggests disabling
> keep-alives when the frontend proxy has a long-open keep-alive connections)
Again, we have client-facing load balancers (F5s) that currently talk to
Apache/mod_perl. So, to be clear, I'm talking about replacing
Apache/mod_perl with Starman so the F5 talks directly to Starman (or
Server::Starter, I suppose when making a connection).
Now, we are on a WAN with multiple datacenters, so it's possible that the
F5 and Apache (or Starman) app servers are not in the same location. I
don't know how significant that latency is, but that's why we would prefer
to use keep-alives on the backend. At least according to our network
I'd have to check, but IIRC, the F5s don't pre-connect -- that is when a
client request comes in and needs to be passed to a backend server the F5
creates a new connection if one does not exist (from a keep-alive). In
other words, I don't think the F5 pre-connects before it has a request to
I guess it's time to test, but if I really needed to use the keep-alives
would I then need to do something similar with Starman and catch the
SIGQUIT and then add a "Connection: close" header to the response to free
up the child to exit after that response? I'm not clear if that's just a
"problem" with Apache or if it also would apply to Starman.