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  • Committer: Jorge Niedbalski
  • Date: 2015-02-18 20:24:50 UTC
  • mfrom: (64.1.15 memcached)
  • Revision ID: jorge.niedbalski@canonical.com-20150218202450-k2kslavk9ic180x0
[niedbalski, r=freyes, billy-olsen] Adds replication support for memcacehd. Fixes bug LP: #1421660

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hooks/memcached_hooks.py
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#!/usr/bin/env python
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__author__ = 'Felipe Reyes <felipe.reyes@canonical.com>'
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import re
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import os
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import shutil
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import subprocess
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import sys
 
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import time
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from charmhelpers.core.hookenv import (
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    config,
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    service_start,
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    service_stop,
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)
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from charmhelpers.fetch import apt_install, apt_update
 
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from charmhelpers.contrib.hahelpers.cluster import (
 
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    oldest_peer,
 
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    peer_units,
 
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)
 
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from charmhelpers.fetch import apt_install, apt_update, add_source
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from charmhelpers.contrib.network import ufw
 
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import memcached_utils
 
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import replication
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__author__ = 'Felipe Reyes <felipe.reyes@canonical.com>'
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DOT = os.path.dirname(os.path.abspath(__file__))
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ETC_DEFAULT_MEMCACHED = '/etc/default/memcached'
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MEMCACHE_NAGIOS_PLUGIN = '/usr/local/lib/nagios/plugins/check_memcache.py'
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RESTART_MAP = {ETC_MEMCACHED_CONF: ['memcached'],
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               ETC_MUNIN_NODE_CONF: ['munin-node']}
 
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hooks = Hooks()
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@hooks.hook('install')
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def install():
 
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    enable_repcached = config('repcached')
 
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    if enable_repcached:
 
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        add_source(config('repcached_origin'))
 
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    apt_update(fatal=True)
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    apt_install(["memcached", "python-cheetah", "python-memcache"], fatal=True)
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        f.write('ENABLE_MEMCACHED=yes\n')
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    ufw.enable()
 
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    if enable_repcached:
 
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        ufw.service(config('repcached_port'), 'open')
 
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    ufw.service('ssh', 'open')
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    service_stop('memcached')
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@hooks.hook('cluster-relation-joined')
 
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def cluster_relation_joined():
 
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    if not config('repcached'):
 
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        return config_changed()
 
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    peers = peer_units()
 
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    if peers and not oldest_peer(peers):
 
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        log("Delaying operation to oldest peer", level='INFO')
 
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        return
 
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    replica = replication.get_repcached_replica()
 
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    if not replica:
 
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        replica = replication.set_repcached_replica()
 
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    master, replica = replica
 
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    log("Setting replication with peer unit: %s" % replica, level="INFO")
 
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    config_changed(replica=replica)
 
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@hooks.hook('cluster-relation-changed')
 
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def cluster_relation_changed():
 
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    if not config('repcached'):
 
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        return config_changed()
 
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    peers = peer_units()
 
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    if peers and oldest_peer(peers):
 
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        log("Delaying operation to secondary peer", level='INFO')
 
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        return
 
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    retries = 0
 
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    while retries < 3:
 
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        log('Waiting for master memcached node to become available',
 
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            level='INFO')
 
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        secondary = relation_get('replica')
 
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        try:
 
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            if secondary == unit_get('private-address'):
 
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                replication.store_replica(relation_get('master'), secondary)
 
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                return config_changed(replica=relation_get('master'))
 
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            elif secondary is None:
 
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                raise AttributeError()
 
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            else:
 
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                msg = """This unit will be marked as failed because
 
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                Repcached replication only can take place between two units.
 
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                If you want to disable this set 'juju set repcached=false'"""
 
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                log(msg, level='WARN')
 
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                raise Exception(msg)
 
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        except AttributeError:
 
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            log("Master not yet available, waiting for %d secs" %
 
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                replication.REPCACHED_MASTER_WAIT)
 
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            time.sleep(replication.REPCACHED_MASTER_WAIT)
 
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            retries += 1
 
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@hooks.hook('cache-relation-joined')
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def cache_relation_joined():
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@hooks.hook('config-changed')
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@restart_on_change(RESTART_MAP)
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def config_changed():
 
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def config_changed(replica=None):
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    mem_size = config('size')
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    if mem_size == 0:
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        mem_size = int(re.findall(r'\d+', output.split('\n')[2])[1])
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        mem_size = int(mem_size * 0.9)
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    if config('repcached'):
 
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        # If repcached was enabled after install, we need
 
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        # to make sure to install the memcached package with replication
 
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        # enabled.
 
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        if not memcached_utils.dpkg_info_contains('memcached',
 
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                                                  'version',
 
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                                                  'repcache'):
 
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            add_source(config('repcached_origin'))
 
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            apt_update(fatal=True)
 
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            apt_install(["memcached"], fatal=True)
 
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        if not replica:
 
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            replica = replication.get_current_replica()
 
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    elif (
 
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        config('repcached') and
 
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        os.path.exists(replication.REPCACHED_REPLICA_FILE)
 
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    ):
 
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        log("Replication has been disabled, removing from this unit",
 
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            level='INFO')
 
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        ufw.service(config('repcached_port'), 'close')
 
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        os.remove(replication.REPCACHED_REPLICA_FILE)
 
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        replica = None
 
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    configs = {'mem_size': mem_size,
 
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               'replica': replica,
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               'large_pages_enabled': False}
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    if replica:
 
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        configs['repcached_port'] = config('repcached_port')
 
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        ufw.service(config('repcached_port'), 'open')
 
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    for key in ['request-limit', 'min-item-size', 'slab-page-size', 'threads',
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                'disable-auto-cleanup', 'disable-cas', 'factor',
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                'connection-limit', 'tcp-port', 'udp-port']: