pvc/node-daemon/pvcnoded/fencing.py
Joshua M. Boniface 726501f4d4 Add additional logging to flush selector
Adds additional debug logging to the flush selector to determine how any
why any given node is selected. Useful for troubleshooting strange
choices.
2020-10-20 12:34:18 -04:00

160 lines
6.9 KiB
Python

#!/usr/bin/env python3
# fencing.py - PVC daemon function library, node fencing functions
# Part of the Parallel Virtual Cluster (PVC) system
#
# Copyright (C) 2018-2020 Joshua M. Boniface <joshua@boniface.me>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
#
###############################################################################
import time
import pvcnoded.zkhandler as zkhandler
import pvcnoded.common as common
import pvcnoded.VMInstance as VMInstance
#
# Fence thread entry function
#
def fenceNode(node_name, zk_conn, config, logger):
# We allow exactly 6 saving throws (30 seconds) for the host to come back online or we kill it
failcount_limit = 6
failcount = 0
while failcount < failcount_limit:
# Wait 5 seconds
time.sleep(config.keepalive_interval)
# Get the state
node_daemon_state = zkhandler.readdata(zk_conn, '/nodes/{}/daemonstate'.format(node_name))
# Is it still 'dead'
if node_daemon_state == 'dead':
failcount += 1
logger.out('Node "{}" failed {}/{} saving throws'.format(node_name, failcount, failcount_limit), state='w')
# It changed back to something else so it must be alive
else:
logger.out('Node "{}" passed a saving throw; canceling fence'.format(node_name), state='o')
return
logger.out('Fencing node "{}" via IPMI reboot signal'.format(node_name), state='w')
# Get IPMI information
ipmi_hostname = zkhandler.readdata(zk_conn, '/nodes/{}/ipmihostname'.format(node_name))
ipmi_username = zkhandler.readdata(zk_conn, '/nodes/{}/ipmiusername'.format(node_name))
ipmi_password = zkhandler.readdata(zk_conn, '/nodes/{}/ipmipassword'.format(node_name))
# Shoot it in the head
fence_status = rebootViaIPMI(ipmi_hostname, ipmi_username, ipmi_password, logger)
# Hold to ensure the fence takes effect and system stabilizes
time.sleep(config.keepalive_interval * 2)
# Force into secondary network state if needed
if node_name in config['coordinators']:
logger.out('Forcing secondary status for node "{}"'.format(node_name), state='i')
zkhandler.writedata(zk_conn, { '/nodes/{}/routerstate'.format(node_name): 'secondary' })
if zkhandler.readdata(zk_conn, '/primary_node') == node_name:
zkhandler.writedata(zk_conn, { '/primary_node': 'none' })
# If the fence succeeded and successful_fence is migrate
if fence_status and config['successful_fence'] == 'migrate':
migrateFromFencedNode(zk_conn, node_name, config, logger)
# If the fence failed and failed_fence is migrate
if not fence_status and config['failed_fence'] == 'migrate' and config['suicide_intervals'] != '0':
migrateFromFencedNode(zk_conn, node_name, config, logger)
# Migrate hosts away from a fenced node
def migrateFromFencedNode(zk_conn, node_name, config, logger):
logger.out('Migrating VMs from dead node "{}" to new hosts'.format(node_name), state='i')
# Get the list of VMs
dead_node_running_domains = zkhandler.readdata(zk_conn, '/nodes/{}/runningdomains'.format(node_name)).split()
# Set the node to a custom domainstate so we know what's happening
zkhandler.writedata(zk_conn, { '/nodes/{}/domainstate'.format(node_name): 'fence-flush' })
# Migrate a VM after a flush
def fence_migrate_vm(dom_uuid):
VMInstance.flush_locks(zk_conn, logger, dom_uuid)
target_node = common.findTargetNode(zk_conn, config, logger, dom_uuid)
if target_node is not None:
logger.out('Migrating VM "{}" to node "{}"'.format(dom_uuid, target_node), state='i')
zkhandler.writedata(zk_conn, {
'/domains/{}/state'.format(dom_uuid): 'start',
'/domains/{}/node'.format(dom_uuid): target_node,
'/domains/{}/lastnode'.format(dom_uuid): node_name
})
else:
logger.out('No target node found for VM "{}"; VM will autostart on next unflush/ready of current node'.format(dom_uuid), state='i')
zkhandler.writedata(zk_conn, {
'/domains/{}/state'.format(dom_uuid): 'stopped',
'/domains/{}/node_autostart'.format(dom_uuid): 'True'
})
# Loop through the VMs
for dom_uuid in dead_node_running_domains:
fence_migrate_vm(dom_uuid)
# Set node in flushed state for easy remigrating when it comes back
zkhandler.writedata(zk_conn, { '/nodes/{}/domainstate'.format(node_name): 'flushed' })
#
# Perform an IPMI fence
#
def rebootViaIPMI(ipmi_hostname, ipmi_user, ipmi_password, logger):
# Forcibly reboot the node
ipmi_command_reset = '/usr/bin/ipmitool -I lanplus -H {} -U {} -P {} chassis power reset'.format(
ipmi_hostname, ipmi_user, ipmi_password
)
ipmi_reset_retcode, ipmi_reset_stdout, ipmi_reset_stderr = common.run_os_command(ipmi_command_reset)
time.sleep(2)
# Ensure the node is powered on
ipmi_command_status = '/usr/bin/ipmitool -I lanplus -H {} -U {} -P {} chassis power status'.format(
ipmi_hostname, ipmi_user, ipmi_password
)
ipmi_status_retcode, ipmi_status_stdout, ipmi_status_stderr = common.run_os_command(ipmi_command_status)
# Trigger a power start if needed
if ipmi_status_stdout != "Chassis Power is on":
ipmi_command_start = '/usr/bin/ipmitool -I lanplus -H {} -U {} -P {} chassis power on'.format(
ipmi_hostname, ipmi_user, ipmi_password
)
ipmi_start_retcode, ipmi_start_stdout, ipmi_start_stderr = common.run_os_command(ipmi_command_start)
# Declare success or failure
if ipmi_reset_retcode == 0:
logger.out('Successfully rebooted dead node', state='o')
return True
else:
logger.out('Failed to reboot dead node', state='e')
print(ipmi_reset_stderr)
return False
#
# Verify that IPMI connectivity to this host exists (used during node init)
#
def verifyIPMI(ipmi_hostname, ipmi_user, ipmi_password):
ipmi_command_status = '/usr/bin/ipmitool -I lanplus -H {} -U {} -P {} chassis power status'.format(
ipmi_hostname, ipmi_user, ipmi_password
)
ipmi_status_retcode, ipmi_status_stdout, ipmi_status_stderr = common.run_os_command(ipmi_command_status, timeout=2)
if ipmi_status_retcode == 0 and ipmi_status_stdout != "Chassis Power is on":
return True
else:
return False