Re: [libvirt] [PATCH v2] libvirt-guests: Add parallel startup and shutdown of guests

On 03/01/2012 07:23 AM, Peter Krempa wrote: > With this patch, it's possible to shut down guests in parallel. Parallel > startup was possible before, but this functionality was not documented > properly. > > To enable parallel startup set the START_DELAY to 0. > > Parallel shutdown has a configurable parameter PARALLEL_SHUTDOWN that > defines the number of machines being shut down in parallel. Enabling > this feature changes the semantics of SHUTDOWN_TIMEOUT parameter that is > applied as a cumulative timeout to shutdown all guests on a URI. > --- > +# shutdown_guests_parallel URI GUESTS > +# Shutdown guests GUESTS on machine URI in parallel > +shutdown_guests_parallel() > +{ > + uri=$1 > + guests=$2 > + > + on_shutdown= check_timeout=false > + timeout=$SHUTDOWN_TIMEOUT if [ $timeout -gt 0 ]; then check_timeout=true fi > + while [ -n "$on_shutdown" ] || [ -n "$guests" ]; do > + while [ -n "$guests" ]&& > + [ $(guest_count "$on_shutdown") -lt "$PARALLEL_SHUTDOWN" ]; do > + set -- $guests > + guest=$1 > + shift > + guests=$* > + shutdown_guest_async "$uri" "$guest" > + on_shutdown="$on_shutdown $guest" > + done > + sleep 1 if $check_timeout; then > + timeout=$(($timeout - 1)) > + if [ $timeout -le 0 ]; then > + eval_gettext "Timeout expired while shutting down domains"; echo > + RETVAL=1 > + return > + fi fi > + on_shutdown_prev=$on_shutdown > + on_shutdown=$(check_guests_shutdown "$uri" "$on_shutdown") > + print_guests_shutdown "$uri" "$on_shutdown_prev" "$on_shutdown" > + done > +} > + > > -# number of seconds we're willing to wait for a guest to shut down > +# If set to non-zero, shutdown will suspend guests concurrently. Number of > +# guests on shutdown at any time will not exceed number set in this variable. > +#PARALLEL_SHUTDOWN=0 > + > +# Number of seconds we're willing to wait for a guest to shut down. If parallel > +# shutdown is enabled, this timeout applies as a timeout for shutting down all > +# guests on a single URI defined in the variable URIS. This must be set to > +# a nonzero positive value if the shutdown action is requested. Change the last sentence: If this is 0, then there is no time out (use with caution, as guests might not respond to a shutdown request). (Hmm, maybe we want to default to 300 [5 minutes], and document our non-zero default, so that you have to explicitly request 0 to avoid timeouts.) ACK with those lines added to shutdown_guests_parallel, and the wording change to the config file, and with the optional change to the timeout default.