On Sun, 2020-08-09 at 20:24 +0200, Niklas Lochschmidt wrote: > Thank you, Oleg. Just to confirm. The code you send is equivalent to > just a lower grace period in the 4.x API, e.g. it will terminate > legitimate inflight connections as well, not only the idle > connections, right?
Correct. > At least that is what I am seeing from my tests. > > Some background: I actually want to have one particular service built > on http4k, that is scaled up and back down to zero pretty frequently. > Sometimes it has to serve API requests that take up to 10 or 15 > seconds to complete (doing a larger amount of fan-out http requests > to other APIs). That means I would want to set a higher grace period > even, but that will mean the service will always take long to shut > down. > > Using http4k I can easily switch to a different server backend, but I > was using this one and was very happy with it's performance. Kudos > for that! > > Of course the "real" solution is to switch to a background worker > setup with queues, but so far it was unnecessary. > > If I can piece together a good testcase I'll open an issue on Jira. I > guess this would be something that would only land in 5.x and not be > backported into 4.x anymore? > We are not planning to add new features to 4.x or back-port features from 5.x. All our limited resources will have to allocated to building 5.1 and maintaining 5.0. Oleg > Niklas > > Oleg Kalnichevski <ol...@apache.org> schrieb am So., 9. Aug. 2020, > 13:00: > > On Fri, 2020-08-07 at 20:04 +0200, Niklas Lochschmidt wrote: > > > I am trying to use the graceful shutdown of HttpServer server > > for > > > http4k, using HttpCore 4.4.13 and 5.0.1. I am creating the server > > > simply > > > using `ServerBootstrap.bootstrap().register(...).create()` and > > > shutting > > > down with `shutdown(5, TimeUnit.SECONDS)` and > > > `close(CloseMode.GRACEFUL)` respectively. Here is what I am > > seeing: > > > > > > - When the server has never been requested it shuts down > > instantly > > > ✔️ > > > - When the server has been requested by a client without keep- > > alive > > > it > > > shuts down instantly ✔️ > > > - When the server has been requested by a client with keep-alive > > and > > > the > > > request is in-flight during shutdown it shuts down as soon as > > the > > > request is done ✔️ > > > > > > The problem is, when I connected with a client that uses keep- > > alive, > > > and > > > the request has been handled by the server and now the client is > > > holding > > > the connection open, then when I shutdown the server, the server > > > will > > > take the whole grace period to shutdown at which point the keep- > > > alive > > > connections are finally being force-closed. > > > > > > Is it possible to somehow speed up the shutdown also in this > > case > > > without terminating in-flight requests? Is there maybe a > > workaround > > > to > > > terminate all idle connections with keep-alives immediately > > before > > > shutdown? > > > > > > > The problem is there is no way of reliably testing whether a > > connection > > is idle or not, as connections can become active immediately after > > passing inactivity test. > > > > What could be a reasonable solution in many cases is to reduce the > > default grace period timeout. > > > > This will make the server await connection termination for 1 second > > instead of 5 seconds. > > ``` > > HttpServer server = ServerBootstrap.bootstrap().create(); > > server.initiateShutdown(); > > server.awaitTermination(TimeValue.ofSeconds(1)); > > server.close(CloseMode.IMMEDIATE); > > ``` > > > > Having said that there might be a better way to detect idle server- > > side > > connections as well. Feel free to raise a request in JIRA if you > > want > > me to look into that. > > > > Oleg > > > > --------------------------------------------------------------------- To unsubscribe, e-mail: httpclient-users-unsubscr...@hc.apache.org For additional commands, e-mail: httpclient-users-h...@hc.apache.org
