From a79a6d8775171ad5cceda9bb3a77946ba60e26ce Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Thu, 7 Nov 2013 05:13:59 +0000 Subject: doc: recommend worker_processes if the app uses SIGCHLD If worker_processes are not enabled, our SIGCHLD handler may conflict with one installed by the application. Fortunately it is uncommon in Ruby web apps to rely on SIGCHLD, but it happens and that is bad. --- Documentation/yahns_config.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/yahns_config.txt b/Documentation/yahns_config.txt index 2505907..45bcfd9 100644 --- a/Documentation/yahns_config.txt +++ b/Documentation/yahns_config.txt @@ -495,6 +495,12 @@ Ruby it is running under. pthread_atfork(3)-style hooks. See WORKER_PROCESSES-LEVEL DIRECTIVES for details. + Using worker_processes is strongly recommended if your application + relies on using a SIGCHLD handler for reaping forked processes. + Without worker_processes, yahns must reserve SIGCHLD for rolling + back SIGUSR2 upgrades, leading to conflicts if the appplication + expects to handle SIGCHLD. + Default: nil (single process, no master/worker separation) ## WORKER_PROCESSES-LEVEL DIRECTIVES -- cgit v1.2.3-24-ge0c7