Skip to content

docs: pipeline: inputs: forward: document signal_object_memory_limit #2790

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
eschabell merged 1 commit into from
Oct 24, 2026
Merged

docs: pipeline: inputs: forward: document signal_object_memory_limit #2790

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
33 changes: 17 additions & 16 deletions pipeline/inputs/forward.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,23 +10,24 @@ _Forward_ is the protocol used by [Fluent Bit](https://fluentbit.io) and [Fluent

The plugin supports the following configuration parameters:

| Key | Description | Default |
|:--------------------|:-------------|:----------|
| `buffer_chunk_size` | By default the buffer to store the incoming Forward messages, don't allocate the maximum memory allowed, instead it allocate memory when it's required. The rounds of allocations are set by `buffer_chunk_size`. The value must be according to the [Unit Size ](../../administration/configuring-fluent-bit.md#unit-sizes)specification. | `1024000` |
| `buffer_max_size` | Specify the maximum buffer memory size used to receive a Forward message. This limit also applies to incoming payloads and decompressed data; payloads exceeding this size are rejected and the connection is closed. The value must be according to the [Unit Size](../../administration/configuring-fluent-bit.md#unit-sizes) specification. | `6144000` |
| `empty_shared_key` | Enable secure forward protocol with a zero-length shared key. Use this to enable user authentication without requiring a shared key, or to connect to Fluentd with a zero-length shared key. | `false` |
| `listen` | Listener network interface. | `0.0.0.0` |
| Key | Description | Default |
| :--- | :--- | :--- |
| `buffer_chunk_size` | By default the buffer to store the incoming Forward messages, don't allocate the maximum memory allowed, instead it allocate memory when it's required. The rounds of allocations are set by `buffer_chunk_size`. The value must be according to the [Unit Size](../../administration/configuring-fluent-bit.md#unit-sizes) specification. | `1024000` |
| `buffer_max_size` | Specify the maximum buffer memory size used to receive a Forward message. This limit also applies to incoming payloads and decompressed data; payloads exceeding this size are rejected and the connection is closed. The value must be according to the [Unit Size](../../administration/configuring-fluent-bit.md#unit-sizes) specification. | `6144000` |
| `empty_shared_key` | Enable secure forward protocol with a zero-length shared key. Use this to enable user authentication without requiring a shared key, or to connect to Fluentd with a zero-length shared key. | `false` |
| `listen` | Listener network interface. | `0.0.0.0` |
| `msgpack_memory_limit` | In v5.1.4 or later, sets the maximum memory used to decode the MessagePack data of an incoming Forward message, including the entries of `PackedForward` payloads. If a message exceeds this limit, the plugin logs the warning `invalid frame or MessagePack allocation budget exceeded` and closes the connection. A value of `0` sets the limit to 16 times `buffer_max_size`, with a minimum of 64 KiB. The value must be according to the [Unit Size](../../administration/configuring-fluent-bit.md#unit-sizes) specification. | `0` |
| `port` | TCP port to listen for incoming connections. | `24224` |
| `security.users` | Specify the username and password pairs for secure forward authentication. Requires `shared_key` or `empty_shared_key` to be set. | |
| `self_hostname` | Hostname for secure forward authentication. | `localhost` |
| `shared_key` | Shared key for secure forward authentication. | _none_ |
| `tag` | Override the tag of the forwarded events with the defined value. In v5.1.3 or later, if `tag` and `tag_prefix` aren't set and an incoming tag is empty, the input name is used. If `tag_prefix` is set, it's applied to the incoming tag instead. | _none_ |
| `tag_prefix` | Prefix incoming tag with the defined value. | _none_ |
| `threaded` | Indicates whether to run this input in its own [thread](../../administration/multithreading.md#inputs). | `false` |
| `unix_path` | Specify the path to Unix socket to receive a Forward message. If set, `listen` and `port` are ignored. | _none_ |
| `unix_perm` | Set the permission of the Unix socket file. If `unix_path` isn't set, this parameter is ignored. | _none_ |
| `workers` | The number of listener workers that accept and process incoming connections. Not supported with `unix_path`; a value greater than `1` while `unix_path` is set causes startup to fail. | `1` |
| `port` | TCP port to listen for incoming connections. | `24224` |
| `security.users` | Specify the username and password pairs for secure forward authentication. Requires `shared_key` or `empty_shared_key` to be set. | _none_ |
| `self_hostname` | Hostname for secure forward authentication. | `localhost` |
| `shared_key` | Shared key for secure forward authentication. | _none_ |
| `signal_object_memory_limit` | In v5.1.5 or later, sets the estimated maximum memory used to decode the metrics or traces in an incoming `PackedForward` or `CompressedPackedForward` message. For `CompressedPackedForward` messages, the limit applies to the decompressed data. Each top-level MessagePack object, array element, and map entry counts as 1024 bytes, so this is an estimate, not an exact memory limit. If a message exceeds this limit, the plugin logs the warning `PackedForward signal object budget exceeded or invalid payload` and closes the connection. This limit is independent of `msgpack_memory_limit`. The value must be at least 1024 bytes and must be according to the [Unit Size](../../administration/configuring-fluent-bit.md#unit-sizes) specification. | `100M` |
| `tag` | Override the tag of the forwarded events with the defined value. In v5.1.3 or later, if `tag` and `tag_prefix` aren't set and an incoming tag is empty, the input name is used. If `tag_prefix` is set, it's applied to the incoming tag instead. | _none_ |
| `tag_prefix` | Prefix incoming tag with the defined value. | _none_ |
| `threaded` | Indicates whether to run this input in its own [thread](../../administration/multithreading.md#inputs). | `false` |
| `unix_path` | Specify the path to Unix socket to receive a Forward message. If set, `listen` and `port` are ignored. | _none_ |
| `unix_perm` | Set the permission of the Unix socket file. If `unix_path` isn't set, this parameter is ignored. | _none_ |
| `workers` | The number of listener workers that accept and process incoming connections. Not supported with `unix_path`; a value greater than `1` while `unix_path` is set causes startup to fail. | `1` |

### Payload validation

Expand Down
Loading