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Diffstat (limited to 'doc/server/plugins/generators/tgenshi/ganglia.txt')
| -rw-r--r-- | doc/server/plugins/generators/tgenshi/ganglia.txt | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/doc/server/plugins/generators/tgenshi/ganglia.txt b/doc/server/plugins/generators/tgenshi/ganglia.txt new file mode 100644 index 000000000..1ad737900 --- /dev/null +++ b/doc/server/plugins/generators/tgenshi/ganglia.txt @@ -0,0 +1,174 @@ +.. -*- mode: rst -*- + +.. _server-plugins-generators-tgenshi-ganglia: + +ganglia +======= + +Another interesting example of **TGenshi** templating is to automatically +generate ``gmond``/``gmetad`` configuration files. The idea is that each +cluster is headless: it communicates with the rest of the cluster members +on an isolated multicast IP address and port. Any of the cluster members +is therefore isolated on that particular ip/port pair. Additionally, +each ``gmond`` instance **also** listens on UDP. This allows for any of +the cluster members to be polled for information on the entire cluster! + +The second part of the trick is in ``gmetad.conf``. Here, we dynamically +generate a list of clusters (based on profiles names) and a list of +members to poll (based on the clients in said profiles). As the number of +profiles and client grows, this list will grow automatically as well. When +a new host is added, ``gmetad`` will receive an updated configuration and +act accordingly. + +There **is** one caveat though. The ``gmetad.conf`` parser is hard coded +to read 16 arguments per ``data_source`` line. If you have more than 15 +nodes in a cluster, you will see a warning in the logs. You can either +ignore it, or truncate the list to the first 15 members. + +In our environment, a profile is a one to one match with the role of +that particular host. You can also do this based on groups, or any other +client property. + +Bundler/ganglia.xml +------------------- + +.. code-block:: xml + + <Bundle name='ganglia' version='2.0' revision='$Revision$' origin='$HeadURL$' > + <Package name='ganglia-gmond' /> + <Package name='ganglia-gmond-modules-python' /> + <ConfigFile name='/etc/ganglia/gmond.conf' /> + <Service name='gmond' /> + <Action name='gmond-reload' /> + + <Group name='gmetad-server'> + <Package name='ganglia-gmetad'/> + <Package name='ganglia-web'/> + <Package name='rrdtool'/> + <ConfigFile name='/etc/ganglia/gmetad.conf' /> + <Service name='gmetad' /> + </Group> + </Bundle> + +Rules/services-ganglia.xml +-------------------------- + +.. code-block:: xml + + <Rules priority='10' revision='$Revision$' origin='$HeadURL$' > + <Service name='gmond' type='chkconfig' status='on' /> + <Group name='gmetad-server'> + <Service name='gmetad' type='chkconfig' status='on' /> + </Group> + </Rules> + +TGenshi/etc/ganglia/gmetad.conf/template.newtxt +----------------------------------------------- + +:: + + {% python + client_metadata = metadata.query.all() + profile_array = {} + seen = [] + for item in client_metadata: + if item.profile not in seen: + seen.append(item.profile) + profile_array[item.profile]=[] + profile_array[item.profile].append(item.hostname) + seen.sort() + %}\ + + gridname "Our Grid" + + {% for profile in seen %} + data_source "${profile}" \ + {% for host in profile_array[profile] %}\ + ${host} \ + {% end %}\ + {% end %} + + rrd_rootdir "/var/lib/ganglia/rrds" + +TGenshi/etc/ganglia/gmond.conf/template.newtxt +---------------------------------------------- + +:: + + {% python + from genshi.builder import tag + import random + random.seed(metadata.profile) + last_octet=random.randint(2,254) + %}\ + /* + $$Id$$ + $$HeadURL$$ + */ + + /* This configuration is as close to 2.5.x default behavior as possible + The values closely match ./gmond/metric.h definitions in 2.5.x */ + globals { + daemonize = yes + setuid = yes + user = nobody + debug_level = 0 + max_udp_msg_len = 1472 + mute = no + deaf = no + host_dmax = 1800 /* 30 minutes */ + cleanup_threshold = 604800 /*secs=1 week */ + gexec = no + send_metadata_interval = 0 + } + + /* If a cluster attribute is specified, then all gmond hosts are wrapped inside + * of a <CLUSTER> tag. If you do not specify a cluster tag, then all <HOSTS> will + * NOT be wrapped inside of a <CLUSTER> tag. */ + cluster { + name = "${metadata.profile}" + owner = "user@company.net" + latlong = "unspecified" + url = "unspecified" + } + + /* The host section describes attributes of the host, like the location */ + host { + location = "unspecified" + } + + /* Feel free to specify as many udp_send_channels as you like. Gmond + used to only support having a single channel */ + udp_send_channel { + host = ${metadata.hostname} + port = 8649 + } + udp_send_channel { + mcast_join = 239.2.11.${last_octet} + port = 8649 + ttl = 1 + } + + /* You can specify as many udp_recv_channels as you like as well. */ + udp_recv_channel { + port = 8649 + bind = ${metadata.hostname} + } + udp_recv_channel { + mcast_join = 239.2.11.${last_octet} + bind = 239.2.11.${last_octet} + port = 8649 + } + + /* You can specify as many tcp_accept_channels as you like to share + an xml description of the state of the cluster */ + tcp_accept_channel { + port = 8649 + } + + /* Each metrics module that is referenced by gmond must be specified and + loaded. If the module has been statically linked with gmond, it does not + require a load path. However all dynamically loadable modules must include + a load path. */ + modules { + /* [snip] */ |