Alibaba Cloud

Aliyun OSS plugin for Fluentd


Fluent OSS output plugin buffers event logs in local files and uploads them to OSS periodically in background threads.

This plugin splits events by using the timestamp of event logs. For example, a log ‘2019-04-09 message Hello’ is reached, and then another log ‘2019-04-10 message World’ is reached in this order, the former is stored in “20190409.gz” file, and latter in “20190410.gz” file.

Fluent OSS input plugin reads data from OSS periodically.

This plugin uses MNS on the same region of the OSS bucket. We must setup MNS and OSS event notification before using this plugin.

This document shows how to setup MNS and OSS event notification.

This plugin will poll events from MNS queue and extract object keys from these events, and then will read those objects from OSS. More info at


Output Config

endpoint (string, required)

OSS endpoint to connect to’

Default: -

bucket (string, required)

Your bucket name

Default: -

access_key_id (*secret.Secret, required)

Your access key id Secret

Default: -

aaccess_key_secret (*secret.Secret, required)

Your access secret key Secret

Default: -

path (string, optional)

Path prefix of the files on OSS

Default: fluent/logs

upload_crc_enable (bool, optional)

Upload crc enabled

Default: true

download_crc_enable (bool, optional)

Download crc enabled

Default: true

open_timeout (int, optional)

Timeout for open connections

Default: 10

read_timeout (int, optional)

Timeout for read response

Default: 120

oss_sdk_log_dir (string, optional)

OSS SDK log directory

Default: /var/log/td-agent

key_format (string, optional)

The format of OSS object keys

Default: %{path}/%{time_slice}%{index}%{thread_id}.%{file_extension}

store_as (string, optional)

Archive format on OSS: gzip, json, text, lzo, lzma2

Default: gzip

auto_create_bucket (bool, optional)

desc ‘Create OSS bucket if it does not exists

Default: false

overwrite (bool, optional)

Overwrite already existing path

Default: false

check_bucket (bool, optional)

Check bucket if exists or not

Default: true

check_object (bool, optional)

Check object before creation

Default: true

hex_random_length (int, optional)

The length of %{hex_random} placeholder(4-16)

Default: 4

index_format (string, optional)

sprintf format for %{index}

Default: %d

warn_for_delay (string, optional)

Given a threshold to treat events as delay, output warning logs if delayed events were put into OSS

Default: -

format (*Format, optional)


Default: -

buffer (*Buffer, optional)


Default: -

slow_flush_log_threshold (string, optional)

The threshold for chunk flush performance check. Parameter type is float, not time, default: 20.0 (seconds) If chunk flush takes longer time than this threshold, fluentd logs warning message and increases metric fluentd_output_status_slow_flush_count.

Default: -