Fluentd
1.0
1.0
  • Introduction
  • Overview
    • Life of a Fluentd event
    • Support
    • FAQ
    • Logo
    • fluent-package v5 vs td-agent v4
  • Installation
    • Before Installation
    • Install fluent-package
      • RPM Package (Red Hat Linux)
      • DEB Package (Debian/Ubuntu)
      • .dmg Package (macOS)
      • .msi Installer (Windows)
    • Install calyptia-fluentd
      • RPM Package (Red Hat Linux)
      • DEB Package (Debian/Ubuntu)
      • .dmg Package (macOS)
      • .msi Installer (Windows)
    • Install by Ruby Gem
    • Install from Source
    • Post Installation Guide
    • Obsolete Installation
      • Treasure Agent v4 (EOL) Installation
        • Install by RPM Package v4 (Red Hat Linux)
        • Install by DEB Package v4 (Debian/Ubuntu)
        • Install by .dmg Package v4 (macOS)
        • Install by .msi Installer v4 (Windows)
      • Treasure Agent v3 (EOL) Installation
        • Install by RPM Package v3 (Red Hat Linux)
        • Install by DEB Package v3 (Debian/Ubuntu)
        • Install by .dmg Package v3 (macOS)
        • Install by .msi Installer v3 (Windows)
  • Configuration
    • Config File Syntax
    • Config File Syntax (YAML)
    • Routing Examples
    • Config: Common Parameters
    • Config: Parse Section
    • Config: Buffer Section
    • Config: Format Section
    • Config: Extract Section
    • Config: Inject Section
    • Config: Transport Section
    • Config: Storage Section
    • Config: Service Discovery Section
  • Deployment
    • System Configuration
    • Logging
    • Signals
    • RPC
    • High Availability Config
    • Performance Tuning
    • Multi Process Workers
    • Failure Scenarios
    • Plugin Management
    • Trouble Shooting
    • Fluentd UI
    • Linux Capability
    • Command Line Option
    • Source Only Mode
    • Zero-downtime restart
  • Container Deployment
    • Docker Image
    • Docker Logging Driver
    • Docker Compose
    • Kubernetes
  • Monitoring Fluentd
    • Overview
    • Monitoring by Prometheus
    • Monitoring by REST API
  • Input Plugins
    • tail
    • forward
    • udp
    • tcp
    • unix
    • http
    • syslog
    • exec
    • sample
    • monitor_agent
    • windows_eventlog
  • Output Plugins
    • file
    • forward
    • http
    • exec
    • exec_filter
    • secondary_file
    • copy
    • relabel
    • roundrobin
    • stdout
    • null
    • s3
    • kafka
    • elasticsearch
    • opensearch
    • mongo
    • mongo_replset
    • rewrite_tag_filter
    • webhdfs
    • buffer
  • Filter Plugins
    • record_transformer
    • grep
    • parser
    • geoip
    • stdout
  • Parser Plugins
    • regexp
    • apache2
    • apache_error
    • nginx
    • syslog
    • ltsv
    • csv
    • tsv
    • json
    • msgpack
    • multiline
    • none
  • Formatter Plugins
    • out_file
    • json
    • ltsv
    • csv
    • msgpack
    • hash
    • single_value
    • stdout
    • tsv
  • Buffer Plugins
    • memory
    • file
    • file_single
  • Storage Plugins
    • local
  • Service Discovery Plugins
    • static
    • file
    • srv
  • Metrics Plugins
    • local
  • How-to Guides
    • Stream Analytics with Materialize
    • Send Apache Logs to S3
    • Send Apache Logs to Minio
    • Send Apache Logs to Mongodb
    • Send Syslog Data to Graylog
    • Send Syslog Data to InfluxDB
    • Send Syslog Data to Sematext
    • Data Analytics with Treasure Data
    • Data Collection with Hadoop (HDFS)
    • Simple Stream Processing with Fluentd
    • Stream Processing with Norikra
    • Stream Processing with Kinesis
    • Free Alternative To Splunk
    • Email Alerting like Splunk
    • How to Parse Syslog Messages
    • Cloud Data Logging with Raspberry Pi
  • Language Bindings
    • Java
    • Ruby
    • Python
    • Perl
    • PHP
    • Nodejs
    • Scala
  • Plugin Development
    • How to Write Input Plugin
    • How to Write Base Plugin
    • How to Write Buffer Plugin
    • How to Write Filter Plugin
    • How to Write Formatter Plugin
    • How to Write Output Plugin
    • How to Write Parser Plugin
    • How to Write Storage Plugin
    • How to Write Service Discovery Plugin
    • How to Write Tests for Plugin
    • Configuration Parameter Types
    • Upgrade Plugin from v0.12
  • Plugin Helper API
    • Plugin Helper: Child Process
    • Plugin Helper: Compat Parameters
    • Plugin Helper: Event Emitter
    • Plugin Helper: Event Loop
    • Plugin Helper: Extract
    • Plugin Helper: Formatter
    • Plugin Helper: Inject
    • Plugin Helper: Parser
    • Plugin Helper: Record Accessor
    • Plugin Helper: Server
    • Plugin Helper: Socket
    • Plugin Helper: Storage
    • Plugin Helper: Thread
    • Plugin Helper: Timer
    • Plugin Helper: Http Server
    • Plugin Helper: Service Discovery
  • Troubleshooting Guide
  • Appendix
    • Update from v0.12 to v1
    • td-agent v2 vs v3 vs v4
Powered by GitBook
On this page
  • Methods
  • storage_create(usage: '', type: nil, conf: nil, default_type: nil)
  • Storage Plugin Helper Instance Types
  • Common Methods
  • Plugins using storage

Was this helpful?

  1. Plugin Helper API

Plugin Helper: Storage

The storage plugin helper manages the plugin's internal states.

Here is an example:

require 'fluent/plugin/input'

module Fluent::Plugin
  class ExampleInput < Input
    Fluent::Plugin.register_input('awesome_example', self)

    # 1. Load storage helper
    helpers :storage, :thread

    DEFAULT_STORAGE_TYPE = 'local'

    # Omit `shutdown` and other plugin APIs

    def initialize
      super

      @storage = nil
    end

    def configure(conf)
      super

      # 2. Create storage with unique name
      config = conf.elements(name: 'storage').first
      @storage = storage_create(usage: 'awesome_index', conf: config, default_type: DEFAULT_STORAGE_TYPE)
    end

    def start
      super

      # 3. Call storage plugin helpers get/put methods
      @storage.put(:awesome_index, 0) unless @storage.get(:awesome_index)
      thread_create(:awesome_input_runner, &method(:run))
    end

    def run
      while thread_current_running?
        current_time = Time.now.to_i
        break unless (thread_current_running? && Time.now.to_i <= current_time)
        router.emit('awesome', Fluent::Engine.now, generate)
        sleep 0.1
      end
    end

    def generate
      # 4. Update storage plugin helper's storing value
      @storage.update(:awesome_index) { |v| v + 1 }
    end
  end
end

The created storage is managed by the plugin helper. No need of storage shutdown code in plugin's shutdown. It shutdowns the created storages automatically.

Methods

storage_create(usage: '', type: nil, conf: nil, default_type: nil)

This method executes storage with the given parameters and routine.

  • usage: unique string value (default: '')

  • type: storage plugin type (default: nil)

  • conf: storage plugin configuration (default: nil)

  • default_conf: storage plugin default configuration (default: nil)

Storage Plugin Helper Instance Types

Instance Type

Attributes

Raw | persistent && persistent_always? || otherwise | Persistent Wrapper | persistent | Synchronized Wrapper | !synchronized? |

Raw

Storage plugins will handle as-is.

Persistent Wrapper

This wrapper makes the handled storage plugin operate values persistently.

Synchronized Wrapper

This wrapper makes handled storage plugin operate values synchronically.

Common Methods

Storage plugin helper encapsulates storage plugin implementation. Normally, the following methods will be called by the owner plugin through this plugin helper:

load

This method loads persistently stored value.

save

This method saves value persistently.

get(key)

  • key: symbol value.

This method obtains stored value by key.

fetch(key, defval)

  • key: symbol value.

  • defval: default value.

This method obtains the stored value by key. If missing, it returns the default value.

put(key, value)

  • key: symbol value.

  • value: store value.

This method updates the stored value by key.

delete(key)

  • key: symbol value.

This method deletes the stored value by key.

update(key, &block)

  • key: symbol value.

  • &block: a Proc object.

This method updates the stored value using a Proc object.

Plugins using storage

PreviousPlugin Helper: SocketNextPlugin Helper: Thread

Last updated 3 years ago

Was this helpful?

For more details, see section.

If this article is incorrect or outdated, or omits critical information, please . is an open-source project under . All components are available under the Apache 2 License.

Storage
in_sample
in_windows_eventlog
let us know
Fluentd
Cloud Native Computing Foundation (CNCF)