From 40a24f5ab917863d1549508ae9cf31085955d174 Mon Sep 17 00:00:00 2001 From: Kaleb S KEITHLEY Date: Mon, 14 Dec 2015 09:24:57 -0500 Subject: common-ha: reliable grace using pacemaker notify actions Using *-dead_ip-1 resources to track on which nodes the ganesha.nfsd had died was found to be unreliable. Running `pcs status` in the ganesha_grace monitor action was seen to time out during failover; the HA devs opined that it was, generally, not a good idea to run `pcs status` in a monitor action in any event. They suggested using the notify feature, where the resources on all the nodes are notified when a clone resource agent dies. This change adds a notify action to the ganesha_grace RA. The ganesha_mon RA monitors its ganesha.nfsd daemon. While the daemon is running, it creates two attributes: ganesha-active and grace-active. When the daemon stops for any reason, the attributes are deleted. Deleting the ganesha-active attribute triggers the failover of the virtual IP (the IPaddr RA) to another node where ganesha.nfsd is still running. The ganesha_grace RA monitors the grace-active attribute. When the grace-active attibute is deleted, the ganesha_grace RA stops, and will not restart. This triggers pacemaker to trigger the notify action in the ganesha_grace RAs on the other nodes in the cluster; which send a DBUS message to their ganesha.nfsd. (N.B. grace-active is a bit of a misnomer. while the grace-active attribute exists, everything is normal and healthy. Deleting the attribute triggers putting the surviving ganesha.nfsds into GRACE.) To ensure that the remaining/surviving ganesha.nfsds are put into NFS-GRACE before the IPaddr (virtual IP) fails over there is a short delay (sleep) between deleting the grace-active attribute and the ganesha-active attribute. To summarize: 1. on node 2 ganesha_mon:monitor notices that ganesha.nfsd has died 2. on node 2 ganesha_mon:monitor deletes its grace-active attribute 3. on node 2 ganesha_grace:monitor notices that grace-active is gone and returns OCF_ERR_GENERIC, a.k.a. new error. When pacemaker tries to (re)start ganesha_grace, its start action will return OCF_NOT_RUNNING, a.k.a. known error, don't attempt further restarts. 4. on nodes 1, 3, etc., ganesha_grace:notify receives a post-stop notification indicating that node 2 is gone, and sends a DBUS message to its ganesha.nfsd putting it into NFS-GRACE. 5. on node 2 ganesha_mon:monitor waits a short period, then deletes its ganesha-active attribute. This triggers the IPaddr (virt IP) failover according to constraint location rules. ganesha_nfsd modified to run for the duration, start action is invoked to setup the /var/lib/nfs symlink, stop action is invoked to restore it. ganesha-ha.sh modified accordingly to create it as a clone resource. BUG: 1290865 Change-Id: I1ba24f38fa4338b3aeb17c65645e9f439387ff57 Signed-off-by: Kaleb S KEITHLEY Reviewed-on: http://review.gluster.org/12964 Smoke: Gluster Build System NetBSD-regression: NetBSD Build System CentOS-regression: Gluster Build System Reviewed-on: http://review.gluster.org/13725 --- extras/ganesha/ocf/ganesha_nfsd | 89 ++++++++++++++++++++++------------------- 1 file changed, 47 insertions(+), 42 deletions(-) (limited to 'extras/ganesha/ocf/ganesha_nfsd') diff --git a/extras/ganesha/ocf/ganesha_nfsd b/extras/ganesha/ocf/ganesha_nfsd index e064183daef..a9d3e4d860f 100644 --- a/extras/ganesha/ocf/ganesha_nfsd +++ b/extras/ganesha/ocf/ganesha_nfsd @@ -29,13 +29,16 @@ : ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat} . ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs -if [ -n "$OCF_DEBUG_LIBRARY" ]; then - . $OCF_DEBUG_LIBRARY +if [ -n "${OCF_DEBUG_LIBRARY}" ]; then + . ${OCF_DEBUG_LIBRARY} else : ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat} . ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs fi +OCF_RESKEY_ha_vol_mnt_default="/var/run/gluster/shared_storage" +: ${OCF_RESKEY_ha_vol_mnt=${OCF_RESKEY_ha_vol_mnt_default}} + ganesha_meta_data() { cat < @@ -59,16 +62,16 @@ resource agent for nfs-ganesha. - - - - + + + + END -return $OCF_SUCCESS +return ${OCF_SUCCESS} } ganesha_nfsd_usage() { @@ -78,10 +81,10 @@ ganesha_nfsd_usage() { # Make sure meta-data and usage always succeed case $__OCF_ACTION in meta-data) ganesha_meta_data - exit $OCF_SUCCESS + exit ${OCF_SUCCESS} ;; usage|help) ganesha_usage - exit $OCF_SUCCESS + exit ${OCF_SUCCESS} ;; *) ;; @@ -89,58 +92,60 @@ esac ganesha_nfsd_start() { - return $OCF_SUCCESS + local long_host=$(hostname) + + if [[ -d /var/lib/nfs ]]; then + mv /var/lib/nfs /var/lib/nfs.backup + if [ $? -ne 0 ]; then + ocf_log notice "mv /var/lib/nfs /var/lib/nfs.backup failed" + fi + ln -s ${OCF_RESKEY_ha_vol_mnt}/nfs-ganesha/${long_host}/nfs /var/lib/nfs + if [ $? -ne 0 ]; then + ocf_log notice "ln -s ${OCF_RESKEY_ha_vol_mnt}/nfs-ganesha/${long_host}/nfs /var/lib/nfs failed" + fi + fi + + return ${OCF_SUCCESS} } ganesha_nfsd_stop() { - local short_host=$(hostname -s) - local long_host="" - - if [ "X${OCF_RESOURCE_INSTANCE:0:9}X" = "Xnfs_startX" ]; then - - # if this is any nfs_start, go ahead. worst case we - # find the link already exists and do nothing - long_host=$(hostname) - - if [ -d /var/lib/nfs ]; then - mv /var/lib/nfs /var/lib/nfs.backup - ln -s $OCF_RESKEY_ha_vol_mnt/nfs-ganesha/${long_host}/nfs /var/lib/nfs - if [ $? -ne 0 ]; then - logger "warning: ln -s $OCF_RESKEY_ha_vol_mnt/nfs-ganesha/${long_host}/nfs /var/lib/nfs failed" - fi + if [ -L /var/lib/nfs -a -d /var/lib/nfs.backup ]; then + rm -f /var/lib/nfs + if [ $? -ne 0 ]; then + ocf_log notice "rm -f /var/lib/nfs failed" fi - else - - # if this is a clone resource or is specific to this node - # remove the symlink and restore /var/lib/nfs - - if [ "X${OCF_RESOURCE_INSTANCE}X" = "Xnfs_stopX" ] || - [ "X${OCF_RESOURCE_INSTANCE}X" = "Xnfs_stop-${short_host}X" ]; then - if [ -L /var/lib/nfs -a -d /var/lib/nfs.backup ]; then - rm -f /var/lib/nfs - mv /var/lib/nfs.backup /var/lib/nfs - fi + mv /var/lib/nfs.backup /var/lib/nfs + if [ $? -ne 0 ]; then + ocf_log notice "mv /var/lib/nfs.backup /var/lib/nfs failed" fi fi - return $OCF_SUCCESS + return ${OCF_SUCCESS} } ganesha_nfsd_monitor() { - return $OCF_SUCCESS + # pacemaker checks to see if RA is already running before starting it. + # if we return success, then it's presumed it's already running and + # doesn't need to be started, i.e. invoke the start action. + # return something other than success to make pacemaker invoke the + # start action + if [[ -L /var/lib/nfs ]]; then + return ${OCF_SUCCESS} + fi + return ${OCF_NOT_RUNNING} } ganesha_nfsd_validate() { - return $OCF_SUCCESS + return ${OCF_SUCCESS} } ganesha_nfsd_validate -# logger "ganesha_nfsd ${OCF_RESOURCE_INSTANCE} $__OCF_ACTION" +# ocf_log notice "ganesha_nfsd ${OCF_RESOURCE_INSTANCE} $__OCF_ACTION" # Translate each action into the appropriate function call case $__OCF_ACTION in @@ -151,13 +156,13 @@ stop) ganesha_nfsd_stop status|monitor) ganesha_nfsd_monitor ;; *) ganesha_nfsd_usage - exit $OCF_ERR_UNIMPLEMENTED + exit ${OCF_ERR_UNIMPLEMENTED} ;; esac rc=$? # The resource agent may optionally log a debug message -ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION returned $rc" +ocf_log debug "${OCF_RESOURCE_INSTANCE} ${__OCF_ACTION} returned $rc" exit $rc -- cgit