The file
buffer plugin provides a persistent buffer implementation. It uses files to store buffer chunks on disk.
type | required | default | version |
string | ✔ | | 0.9.0 |
The path where buffer chunks are stored. The '*' is replaced with random characters. This parameter is required.
This parameter must be unique to avoid the race condition problem. For example, you cannot use a fixed path parameter in fluent-plugin-forest
. ${tag}
or similar placeholder is needed. Of course, this parameter must also be unique between fluentd instances.
In addition, path
should not be another path
prefix. For example, the following configuration does not work well. /var/log/fluent/foo
resumes /var/log/fluent/foo.bar
's buffer files during start phase and it causes No such file or directory
in /var/log/fluent/foo.bar
side.
<match pattern1><buffer>@type filepath /var/log/fluent/foo</buffer></match><match pattern2><buffer>@type filepath /var/log/fluent/foo.bar</buffer></match>
Here is the correct version to avoid the prefix problem:
<match pattern1><buffer>@type filepath /var/log/fluent/foo.baz</buffer></match><match pattern2><buffer>@type filepath /var/log/fluent/foo.bar</buffer></match>
Please make sure that you have enough space in the path directory. Running out of disk space is a problem frequently reported by users.
type | default | version |
string | .log | 1.6.3 |
Changes the suffix of the buffer file.
# default/var/log/fluentd/buf/buffer.b58eec11d08ca8143b40e4d303510e0bb.log/var/log/fluentd/buf/buffer.b58eec11d08ca8143b40e4d303510e0bb.log.meta# with 'path_suffix .buf'/var/log/fluentd/buf/buffer.b58eec11d08ca8143b40e4d303510e0bb.buf/var/log/fluentd/buf/buffer.b58eec11d08ca8143b40e4d303510e0bb.buf.meta
This parameter is useful when .log
is not fit for your environment. See also this issue's comment.
<match pattern><buffer>@type filepath /var/log/fluent/myapp.*.buffer</buffer></match>
Caution: file
buffer implementation depends on the characteristics of the local file system. Don't use file
buffer on remote file systems e.g. NFS, GlusterFS, HDFS, etc. We observed major data loss by using the remote file system.
If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is an open-source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache 2 License.