Buffer 🔗︎

Variable Name Type Required Default Description
type string No - Fluentd core bundles memory and file plugins. 3rd party plugins are also available when installed.
tags string No tag,time When tag is specified as buffer chunk key, output plugin writes events into chunks separately per tags.
path string No operator generated The path where buffer chunks are stored. The ‘*’ is replaced with random characters. It’s highly recommended to leave this default.
chunk_limit_size string No - The max size of each chunks: events will be written into chunks until the size of chunks become this size
chunk_limit_records int No - The max number of events that each chunks can store in it
total_limit_size string No - The size limitation of this buffer plugin instance. Once the total size of stored buffer reached this threshold, all append operations will fail with error (and data will be lost)
queue_limit_length int No - The queue length limitation of this buffer plugin instance
chunk_full_threshold string No - The percentage of chunk size threshold for flushing. output plugin will flush the chunk when actual size reaches chunk_limit_size * chunk_full_threshold (== 8MB * 0.95 in default)
queued_chunks_limit_size int No - Limit the number of queued chunks. If you set smaller flush_interval, e.g. 1s, there are lots of small queued chunks in buffer. This is not good with file buffer because it consumes lots of fd resources when output destination has a problem. This parameter mitigates such situations.
compress string No - If you set this option to gzip, you can get Fluentd to compress data records before writing to buffer chunks.
flush_at_shutdown bool No - The value to specify to flush/write all buffer chunks at shutdown, or not
flush_mode string No - Default: default (equals to lazy if time is specified as chunk key, interval otherwise)
lazy: flush/write chunks once per timekey
interval: flush/write chunks per specified time via flush_interval
immediate: flush/write chunks immediately after events are appended into chunks
flush_interval string No - Default: 60s
flush_thread_count int No - The number of threads of output plugins, which is used to write chunks in parallel
flush_thread_interval string No - The sleep interval seconds of threads to wait next flush trial (when no chunks are waiting)
flush_thread_burst_interval string No - The sleep interval seconds of threads between flushes when output plugin flushes waiting chunks next to next
delayed_commit_timeout string No - The timeout seconds until output plugin decides that async write operation fails
overflow_action string No - How output plugin behaves when its buffer queue is full
throw_exception: raise exception to show this error in log
block: block processing of input plugin to emit events into that buffer
drop_oldest_chunk: drop/purge oldest chunk to accept newly incoming chunk
retry_timeout string No - The maximum seconds to retry to flush while failing, until plugin discards buffer chunks
retry_forever *bool No true If true, plugin will ignore retry_timeout and retry_max_times options and retry flushing forever
retry_max_times int No - The maximum number of times to retry to flush while failing
retry_secondary_threshold string No - The ratio of retry_timeout to switch to use secondary while failing (Maximum valid value is 1.0)
retry_type string No - exponential_backoff: wait seconds will become large exponentially per failures
periodic: output plugin will retry periodically with fixed intervals (configured via retry_wait)
retry_wait string No - Seconds to wait before next retry to flush, or constant factor of exponential backoff
retry_exponential_backoff_base string No - The base number of exponential backoff for retries
retry_max_interval string No - The maximum interval seconds for exponential backoff between retries while failing
retry_randomize bool No - If true, output plugin will retry after randomized interval not to do burst retries
disable_chunk_backup bool No - Instead of storing unrecoverable chunks in the backup directory, just discard them. This option is new in Fluentd v1.2.6.
timekey string Yes 10m Output plugin will flush chunks per specified time (enabled when time is specified in chunk keys)
timekey_wait string No 10m Output plugin writes chunks after timekey_wait seconds later after timekey expiration
timekey_use_utc bool No - Output plugin decides to use UTC or not to format placeholders using timekey
timekey_zone string No - The timezone (-0700 or Asia/Tokyo) string for formatting timekey placeholders