When the sigchld handler is called and waitpid() returns -1,
the behavior of waitpid() with the status variable is undefined.
It is not a good idea to exit with the value contained in it.
Since this exit path does not use the exitcode variable, it means that
this is an expected and successful exit.
This should be backported in 1.9, code has moved,
mworker_catch_sigchld() is in haproxy.c.
Commit 3f12887 ("MINOR: mworker: don't use children variable anymore")
introduced a regression.
The previous behavior was to send a signal to every children, whether or
not they are former children. Instead of this, we only send a signal to
the current children, so we don't try to kill -INT or -TERM all
processes during a reload.
No backport needed.
Since the introduction of the options field, we can use it to store the
type of process.
type = 'm' is replaced by PROC_O_TYPE_MASTER
type = 'w' is replaced by PROC_O_TYPE_WORKER
type = 'e' is replaced by PROC_O_TYPE_PROG
The old values are still used in the HAPROXY_PROCESSES environment
variable to pass the information during a reload.
Previously we were assuming than a process was in a leaving state when
its number of reload was greater than 0. With mworker programs it's not
the case anymore so we need to store a leaving state.
This patch implements the external binary support in the master worker.
To configure an external process, you need to use the program section,
for example:
program dataplane-api
command ./dataplane_api
Those processes are launched at the same time as the workers.
During a reload of HAProxy, those processes are dealing with the same
sequence as a worker:
- the master is re-executed
- the master sends a USR1 signal to the program
- the master launches a new instance of the program
During a stop, or restart, a SIGTERM is sent to the program.
The children variable is still used in haproxy, it is not required
anymore since we have the information about the current workers in the
mworker_proc linked list.
The oldpids array is also replaced by this linked list when we
generated the arguments for the master reexec.
