lib/fluent/plugin/multi_output.rb
#
# Fluentd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
require 'fluent/plugin/base'
require 'fluent/log'
require 'fluent/plugin_id'
require 'fluent/plugin_helper'
module Fluent
module Plugin
class MultiOutput < Base
include PluginId
include PluginLoggerMixin
include PluginHelper::Mixin # for event_emitter
helpers :event_emitter # to get router from agent, which will be supplied to child plugins
helpers_internal :metrics
config_section :store, param_name: :stores, multi: true, required: true do
config_argument :arg, :string, default: ''
config_param :@type, :string, default: nil
end
attr_reader :outputs, :outputs_statically_created
def process(tag, es)
raise NotImplementedError, "BUG: output plugins MUST implement this method"
end
def initialize
super
@outputs = []
@outputs_statically_created = false
@counter_mutex = Mutex.new
# TODO: well organized counters
@num_errors_metrics = nil
@emit_count_metrics = nil
@emit_records_metrics = nil
@emit_size_metrics = nil
# @write_count = 0
# @rollback_count = 0
@enable_size_metrics = false
end
def num_errors
@num_errors_metrics.get
end
def emit_count
@emit_count_metrics.get
end
def emit_size
@emit_size_metrics.get
end
def emit_records
@emit_records_metrics.get
end
def statistics
stats = {
'num_errors' => @num_errors_metrics.get,
'emit_records' => @emit_records_metrics.get,
'emit_count' => @emit_count_metrics.get,
'emit_size' => @emit_size_metrics.get,
}
{ 'multi_output' => stats }
end
def multi_output?
true
end
def configure(conf)
super
@num_errors_metrics = metrics_create(namespace: "fluentd", subsystem: "multi_output", name: "num_errors", help_text: "Number of count num errors")
@emit_count_metrics = metrics_create(namespace: "fluentd", subsystem: "multi_output", name: "emit_records", help_text: "Number of count emits")
@emit_records_metrics = metrics_create(namespace: "fluentd", subsystem: "multi_output", name: "emit_records", help_text: "Number of emit records")
@emit_size_metrics = metrics_create(namespace: "fluentd", subsystem: "multi_output", name: "emit_size", help_text: "Total size of emit events")
@enable_size_metrics = !!system_config.enable_size_metrics
@stores.each do |store|
store_conf = store.corresponding_config_element
type = store_conf['@type']
unless type
raise Fluent::ConfigError, "Missing '@type' parameter in <store> section"
end
log.debug "adding store", type: type
output = Fluent::Plugin.new_output(type)
output.context_router = self.context_router
output.configure(store_conf)
@outputs << output
end
end
def static_outputs
@outputs_statically_created = true
@outputs
end
# Child plugin's lifecycles are controlled by agent automatically.
# It calls `outputs` to traverse plugins, and invoke start/stop/*shutdown/close/terminate on these directly.
# * `start` of this plugin will be called after child plugins
# * `stop`, `*shutdown`, `close` and `terminate` of this plugin will be called before child plugins
# But when MultiOutput plugins are created dynamically (by forest plugin or others), agent cannot find
# sub-plugins. So child plugins' lifecycles MUST be controlled by MultiOutput plugin itself.
# TODO: this hack will be removed at v2.
def call_lifecycle_method(method_name, checker_name)
return if @outputs_statically_created
@outputs.each do |o|
begin
log.debug "calling #{method_name} on output plugin dynamically created", type: Fluent::Plugin.lookup_type_from_class(o.class), plugin_id: o.plugin_id
o.__send__(method_name) unless o.__send__(checker_name)
rescue Exception => e
log.warn "unexpected error while calling #{method_name} on output plugin dynamically created", plugin: o.class, plugin_id: o.plugin_id, error: e
log.warn_backtrace
end
end
end
def start
super
call_lifecycle_method(:start, :started?)
end
def after_start
super
call_lifecycle_method(:after_start, :after_started?)
end
def stop
super
call_lifecycle_method(:stop, :stopped?)
end
def before_shutdown
super
call_lifecycle_method(:before_shutdown, :before_shutdown?)
end
def shutdown
super
call_lifecycle_method(:shutdown, :shutdown?)
end
def after_shutdown
super
call_lifecycle_method(:after_shutdown, :after_shutdown?)
end
def close
super
call_lifecycle_method(:close, :closed?)
end
def terminate
super
call_lifecycle_method(:terminate, :terminated?)
end
def emit_sync(tag, es)
@emit_count_metrics.inc
begin
process(tag, es)
@emit_records_metrics.add(es.size)
@emit_size_metrics.add(es.to_msgpack_stream.bytesize) if @enable_size_metrics
rescue
@num_errors_metrics.inc
raise
end
end
alias :emit_events :emit_sync
end
end
end