Class: Droonga::Serf

Inherits:
Object
  • Object
show all
Includes:
Loggable
Defined in:
lib/droonga/serf.rb,
lib/droonga/serf/tag.rb,
lib/droonga/serf/agent.rb,
lib/droonga/serf/command.rb,
lib/droonga/serf/downloader.rb,
lib/droonga/serf/remote_command.rb

Defined Under Namespace

Modules: RemoteCommand, Tag Classes: Agent, Command, Downloader

Constant Summary collapse

CHECK_RESTARTED_INTERVAL = 
3
CHECK_RESTARTED_TIMEOUT = 
60 * 5

Instance Method Summary collapse

Constructor Details

#initialize(name, options = {}) ⇒ Serf

Returns a new instance of Serf.



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# File 'lib/droonga/serf.rb', line 35

def initialize(name, options={})
  @serf_command = nil
  @name = NodeName.parse(name)
  @verbose = options[:verbose] || false
  @service_installation = ServiceInstallation.new
  @tags_cache = {}
end

Instance Method Details

#accept_messages_newer_than(timestamp) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 212

def accept_messages_newer_than(timestamp)
  set_tag(Tag.accept_messages_newer_than, timestamp)
  # after that you must run update_cluster_state to update the cluster information cache
end

#accept_messages_newer_than_timestamp ⇒ Object 



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# File 'lib/droonga/serf.rb', line 208

def accept_messages_newer_than_timestamp
  get_tag(Tag.accept_messages_newer_than)
end

#cluster_id ⇒ Object 



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# File 'lib/droonga/serf.rb', line 217

def cluster_id
  loader = Catalog::Loader.new(Path.catalog.to_s)
  catalog = loader.load
  catalog.cluster_id
end

#current_cluster_state ⇒ Object 



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# File 'lib/droonga/serf.rb', line 120

def current_cluster_state
  current_cluster_id = cluster_id
  nodes = {}
  unprocessed_messages_existence = {}
  current_members.each do |member|
    foreign = member["tags"][Tag.cluster_id] != current_cluster_id
    next if foreign

    member["tags"].each do |key, value|
      next unless Tag.have_unprocessed_messages_tag?(key)
      node_name = Tag.extract_node_name_from_have_unprocessed_messages_tag(key)
      next if unprocessed_messages_existence[node_name]
      unprocessed_messages_existence[node_name] = value == "true"
    end

    nodes[member["name"]] = {
      "type" => member["tags"][Tag.node_type],
      "role" => member["tags"][Tag.node_role],
      "internal_name" => member["tags"][Tag.internal_node_name],
      "accept_messages_newer_than" => member["tags"][Tag.accept_messages_newer_than],
      "live" => member["status"] == "alive",
    }
  end
  unprocessed_messages_existence.each do |node_name, have_messages|
    nodes[node_name]["have_unprocessed_messages"] = have_messages
  end
  sorted_nodes = {}
  nodes.keys.sort.each do |key|
    sorted_nodes[key] = nodes[key]
  end
  sorted_nodes
end

#current_members ⇒ Object 



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# File 'lib/droonga/serf.rb', line 114

def current_members
  raw_response = run_command("members", "-format", "json")
  response = JSON.parse(raw_response)
  response["members"]
end

#delete_tag(name) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 169

def delete_tag(name)
  run_command("tags", "-delete", name)
  @tags_cache.delete(name)
end

#ensure_restarted(*nodes, &block) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 226

def ensure_restarted(*nodes, &block)
  nodes << @name.to_s if nodes.empty?

  targets = nodes.collect do |node|
    serf = self.class.new(node)
    {
      :serf          => serf,
      :previous_name => serf.get_tag(Tag.internal_node_name),
    }
  end

  start_time = Time.now

  yield # the given operation must restart the service.

  while Time.now - start_time < CHECK_RESTARTED_TIMEOUT
    puts "Checking nodes are restarted or not:" if @verbose
    targets.reject! do |target|
      name = target[:serf].get_tag(Tag.internal_node_name)
      restarted = name != target[:previous_name]
      puts "  #{name} vs #{target[:previous_name]} => " +
             "#{restarted ? "restarted" : "not yet"}" if @verbose
      restarted
    end
    break if targets.empty?
    sleep(CHECK_RESTARTED_INTERVAL)
  end

  targets.empty?
end

#get_tag(name) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 153

def get_tag(name)
  myself = current_members.find do |member|
    member["name"] == @name.to_s
  end
  if myself
    myself["tags"][name]
  else
    nil
  end
end

#initialize_tags ⇒ Object 



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# File 'lib/droonga/serf.rb', line 63

def initialize_tags
  set_tag(Tag.node_type, "engine")
  set_tag(Tag.node_role, role)
  set_tag(Tag.cluster_id, cluster_id)
end

#join(*hosts) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 73

def join(*hosts)
  nodes = hosts.collect do |host|
    "#{host}:#{agent_port}"
  end
  run_command("join", *nodes)
end

#last_message_timestamp ⇒ Object 



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# File 'lib/droonga/serf.rb', line 198

def last_message_timestamp
  response = send_query("report_last_message_timestamp",
                        "node" => @name.to_s)
  if response
    response["timestamp"]
  else
    nil
  end
end

#leave ⇒ Object 



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# File 'lib/droonga/serf.rb', line 69

def leave
  run_command("leave")
end

#reset_have_unprocessed_messages_for(node_name) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 183

def reset_have_unprocessed_messages_for(node_name)
  delete_tag(Tag.have_unprocessed_messages_tag_for(node_name))
end

#role ⇒ Object 



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# File 'lib/droonga/serf.rb', line 187

def role
  NodeRole.normalize(get_tag(Tag.node_role))
end

#role=(new_role) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 191

def role=(new_role)
  role = NodeRole.normalize(new_role)
  set_tag(Tag.node_role, role)
  # after that you must run update_cluster_state to update the cluster information cache
  role
end

#run_agent(loop) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 43

def run_agent(loop)
  logger.trace("run_agent: start")
  ensure_serf
  retry_joins = []
  detect_other_hosts.each do |other_host|
    retry_joins.push("-retry-join", other_host)
  end
  tags_file = Path.serf_tags_file
  FileUtils.mkdir_p(tags_file.dirname)
  agent = Agent.new(loop, @serf_command,
                    @name.host, agent_port, rpc_port,
                    "-node", @name.to_s,
                    "-event-handler", "droonga-engine-serf-event-handler",
                    "-tags-file", tags_file.to_s,
                    *retry_joins)
  agent.start
  logger.trace("run_agent: done")
  agent
end

#send_query(query, payload) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 80

def send_query(query, payload)
  options = ["-format", "json"] + additional_options_from_payload(payload)
  options += [query, JSON.generate(payload)]
  raw_serf_response = run_command("query", *options)
  serf_response = JSON.parse(raw_serf_response)

  node = payload["node"]
  if node
    responses = serf_response["Responses"]
    response = responses[node]
    if response.is_a?(String)
      begin
        JSON.parse(response)
      rescue JSON::ParserError
        response
      end
    else
      response
    end
  else
    response
  end
end

#set_have_unprocessed_messages_for(node_name) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 178

def set_have_unprocessed_messages_for(node_name)
  tag = Tag.have_unprocessed_messages_tag_for(node_name)
  set_tag(tag, true) unless @tags_cache.key?(tag)
end

#set_tag(name, value) ⇒ Object 



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# File 'lib/droonga/serf.rb', line 164

def set_tag(name, value)
  run_command("tags", "-set", "#{name}=#{value}")
  @tags_cache[name] = value
end

#update_cluster_id ⇒ Object 



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# File 'lib/droonga/serf.rb', line 174

def update_cluster_id
  set_tag(Tag.cluster_id, cluster_id)
end

#update_cluster_state ⇒ Object 



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# File 'lib/droonga/serf.rb', line 104

def update_cluster_state
  path = Path.cluster_state
  new_state = current_cluster_state
  file_contents = JSON.pretty_generate(new_state)
  SafeFileWriter.write(path) do |output, file|
    output.puts(file_contents)
    @service_installation.ensure_correct_file_permission(file)
  end
end