filestream input

A list of regular expressions to match the files that you want Filebeat to include. If a list of regexes is provided, only the files that are allowed by the patterns are harvested.

By default no files are excluded. This option is the counterpart of prospector.scanner.exclude_files.

The following example configures Filebeat to exclude files that are not under /var/log:

filebeat.inputs:
- type: filestream
  ...
  prospector.scanner.include_files: ['^/var/log/.*']

See Regular expression support for a list of supported regexp patterns.

The symlinks option allows Filebeat to harvest symlinks in addition to regular files. When harvesting symlinks, Filebeat opens and reads the original file even though it reports the path of the symlink.

When you configure a symlink for harvesting, make sure the original path is excluded. If a single input is configured to harvest both the symlink and the original file, Filebeat will detect the problem and only process the first file it finds. However, if two different inputs are configured (one to read the symlink and the other the original path), both paths will be harvested, causing Filebeat to send duplicate data and the inputs to overwrite each other’s state.

The symlinks option can be useful if symlinks to the log files have additional metadata in the file name, and you want to process the metadata in Logstash. This is, for example, the case for Kubernetes log files.

Because this option may lead to data loss, it is disabled by default.

If this option is enabled a file is resent if its size has not changed but its modification time has changed to a later time than before. It is disabled by default to avoid accidentally resending files.

How often Filebeat checks for new files in the paths that are specified for harvesting. For example, if you specify a glob like /var/log/*, the directory is scanned for files using the frequency specified by check_interval. Specify 1s to scan the directory as frequently as possible without causing Filebeat to scan too frequently. We do not recommend to set this value <1s.

If you require log lines to be sent in near real time do not use a very low check_interval but adjust close.on_state_change.inactive so the file handler stays open and constantly polls your files.

The default setting is 10s.

If this option is enabled, Filebeat ignores any files that were modified before the specified timespan. Configuring ignore_older can be especially useful if you keep log files for a long time. For example, if you want to start Filebeat, but only want to send the newest files and files from last week, you can configure this option.

You can use time strings like 2h (2 hours) and 5m (5 minutes). The default is 0, which disables the setting. Commenting out the config has the same effect as setting it to 0.

The files affected by this setting fall into two categories:

For files which were never seen before, the offset state is set to the end of the file. If a state already exists, the offset is reset to the size of the file. If a file is updated again later, reading continues at the set offset position.

The ignore_older setting relies on the modification time of the file to determine if a file is ignored. If the modification time of the file is not updated when lines are written to a file (which can happen on Windows), the ignore_older setting may cause Filebeat to ignore files even though content was added at a later time.

To remove the state of previously harvested files from the registry file, use the clean_inactive configuration option.

Before a file can be ignored by Filebeat, the file must be closed. To ensure a file is no longer being harvested when it is ignored, you must set ignore_older to a longer duration than close.on_state_change.inactive.

If a file that’s currently being harvested falls under ignore_older, the harvester will first finish reading the file and close it after close.on_state_change.inactive is reached. Then, after that, the file will be ignored.

If this option is enabled, Filebeat ignores every file that has not been updated since the selected time. Possible options are since_first_start and since_last_start. The first option ignores every file that has not been updated since the first start of Filebeat. It is useful when the Beat might be restarted due to configuration changes or a failure. The second option tells the Beat to read from files that have been updated since its start.

The files affected by this setting fall into two categories:

For files that were never seen before, the offset state is set to the end of the file. If a state already exist, the offset is not changed. In case a file is updated again later, reading continues at the set offset position.

The setting relies on the modification time of the file to determine if a file is ignored. If the modification time of the file is not updated when lines are written to a file (which can happen on Windows), the setting may cause Filebeat to ignore files even though content was added at a later time.

To remove the state of previously harvested files from the registry file, use the clean_inactive configuration option.

If take_over is set to true, this filestream will take over all files from log inputs if they match at least one of the paths set in the filestream.

This take over mode was created to enable smooth migration from deprecated log inputs to the new filestream inputs.

See Migrate log input configurations to filestream for more details about the migration process.

The close.* configuration options are used to close the harvester after a certain criteria or time. Closing the harvester means closing the file handler. If a file is updated after the harvester is closed, the file will be picked up again after prospector.scanner.check_interval has elapsed. However, if the file is moved or deleted while the harvester is closed, Filebeat will not be able to pick up the file again, and any data that the harvester hasn’t read will be lost.

The close.on_state_change.* settings are applied asynchronously to read from a file, meaning that if Filebeat is in a blocked state due to blocked output, full queue or other issue, a file that would be closed regardless.

When this option is enabled, Filebeat closes the file handle if a file has not been harvested for the specified duration. The counter for the defined period starts when the last log line was read by the harvester. It is not based on the modification time of the file. If the closed file changes again, a new harvester is started and the latest changes will be picked up after prospector.scanner.check_interval has elapsed.

We recommended that you set close.on_state_change.inactive to a value that is larger than the least frequent updates to your log files. For example, if your log files get updated every few seconds, you can safely set close.on_state_change.inactive to 1m. If there are log files with very different update rates, you can use multiple configurations with different values.

Setting close.on_state_change.inactive to a lower value means that file handles are closed sooner. However this has the side effect that new log lines are not sent in near real time if the harvester is closed.

The timestamp for closing a file does not depend on the modification time of the file. Instead, Filebeat uses an internal timestamp that reflects when the file was last harvested. For example, if close.on_state_change.inactive is set to 5 minutes, the countdown for the 5 minutes starts after the harvester reads the last line of the file.

You can use time strings like 2h (2 hours) and 5m (5 minutes). The default is 5m.

When this option is enabled, Filebeat closes the file handler when a file is renamed. This happens, for example, when rotating files. By default, the harvester stays open and keeps reading the file because the file handler does not depend on the file name. If the close.on_state_change.renamed option is enabled and the file is renamed or moved in such a way that it’s no longer matched by the file patterns specified for the , the file will not be picked up again. Filebeat will not finish reading the file.

Do not use this option when path based file_identity is configured. It does not make sense to enable the option, as Filebeat cannot detect renames using path names as unique identifiers.

WINDOWS: If your Windows log rotation system shows errors because it can’t rotate the files, you should enable this option.

When this option is enabled, Filebeat closes the harvester when a file is removed. Normally a file should only be removed after it’s inactive for the duration specified by close.on_state_change.inactive. However, if a file is removed early and you don’t enable close.on_state_change.removed, Filebeat keeps the file open to make sure the harvester has completed. If this setting results in files that are not completely read because they are removed from disk too early, disable this option.

This option is enabled by default. If you disable this option, you must also disable clean_removed.

WINDOWS: If your Windows log rotation system shows errors because it can’t rotate files, make sure this option is enabled.

When this option is enabled, Filebeat closes a file as soon as the end of a file is reached. This is useful when your files are only written once and not updated from time to time. For example, this happens when you are writing every single log event to a new file. This option is disabled by default.

When this option is enabled, Filebeat gives every harvester a predefined lifetime. Regardless of where the reader is in the file, reading will stop after the close.reader.after_interval period has elapsed. This option can be useful for older log files when you want to spend only a predefined amount of time on the files. While close.reader.after_interval will close the file after the predefined timeout, if the file is still being updated, Filebeat will start a new harvester again per the defined prospector.scanner.check_interval. And the close.reader.after_interval for this harvester will start again with the countdown for the timeout.

This option is particularly useful in case the output is blocked, which makes Filebeat keep open file handlers even for files that were deleted from the disk. Setting close.reader.after_interval to 5m ensures that the files are periodically closed so they can be freed up by the operating system.

If you set close.reader.after_interval to equal ignore_older, the file will not be picked up if it’s modified while the harvester is closed. This combination of settings normally leads to data loss, and the complete file is not sent.

When you use close.reader.after_interval for logs that contain multiline events, the harvester might stop in the middle of a multiline event, which means that only parts of the event will be sent. If the harvester is started again and the file still exists, only the second part of the event will be sent.

This option is set to 0 by default which means it is disabled.

The clean_* options are used to clean up the state entries in the registry file. These settings help to reduce the size of the registry file and can prevent a potential inode reuse issue.

When this option is enabled, Filebeat removes the state of a file after the specified period of inactivity has elapsed. The state can only be removed if the file is already ignored by Filebeat (the file is older than ignore_older). The clean_inactive setting must be greater than ignore_older + prospector.scanner.check_interval to make sure that no states are removed while a file is still being harvested. Otherwise, the setting could result in Filebeat resending the full content constantly because clean_inactive removes state for files that are still detected by Filebeat. If a file is updated or appears again, the file is read from the beginning.

The clean_inactive configuration option is useful to reduce the size of the registry file, especially if a large amount of new files are generated every day.

This config option is also useful to prevent Filebeat problems resulting from inode reuse on Linux. For more information, see Inode reuse causes Filebeat to skip lines.

When this option is enabled, Filebeat cleans files from the registry if they cannot be found on disk anymore under the last known name. This means also files which were renamed after the harvester was finished will be removed. This option is enabled by default.

If a shared drive disappears for a short period and appears again, all files will be read again from the beginning because the states were removed from the registry file. In such cases, we recommend that you disable the clean_removed option.

You must disable this option if you also disable close.on_state_change.removed.

The backoff options specify how aggressively Filebeat crawls open files for updates. You can use the default values in most cases.

The backoff.init option defines how long Filebeat waits for the first time before checking a file again after EOF is reached. The backoff intervals increase exponentially. The default is 2s. Thus, the file is checked after 2 seconds, then 4 seconds, then 8 seconds and so on until it reaches the limit defined in backoff.max. Every time a new line appears in the file, the backoff.init value is reset to the initial value.

The maximum time for Filebeat to wait before checking a file again after EOF is reached. After having backed off multiple times from checking the file, the wait time will never exceed backoff.max. Because it takes a maximum of 10s to read a new line, specifying 10s for backoff.max means that, at the worst, a new line could be added to the log file if Filebeat has backed off multiple times. The default is 10s.

Requirement: Set backoff.max to be greater than or equal to backoff.init and less than or equal to prospector.scanner.check_interval (backoff.init <= backoff.max <= prospector.scanner.check_interval). If backoff.max needs to be higher, it is recommended to close the file handler instead and let Filebeat pick up the file again.

Different file_identity methods can be configured to suit the environment where you are collecting log messages.

file_identity.native: ~

file_identity.path: ~

Set the location of the marker file the following way:

file_identity.inode_marker.path: /logs/.filebeat-marker

As log files are constantly written, they must be rotated and purged to prevent the logger application from filling up the disk. Rotation is done by an external application, thus, Filebeat needs information how to cooperate with it.

When reading from rotating files make sure the paths configuration includes both the active file and all rotated files.

By default, Filebeat is able to track files correctly in the following strategies: * create: new active file with a unique name is created on rotation * rename: rotated files are renamed

However, in case of copytruncate strategy, you should provide additional configuration to Filebeat.

If the log rotating application copies the contents of the active file and then truncates the original file, use these options to help Filebeat to read files correctly.

Set the option suffix_regex so Filebeat can tell active and rotated files apart. There are two supported suffix types in the input: numberic and date.