---
title: "Traefik Logs Documentation"
description: "Logs are a key part of observability in Traefik Proxy. Read the technical documentation to learn their configurations, rotations, and time zones."
---

## Logs

Logs concern everything that happens to Traefik itself (startup, configuration, events, shutdown, and so on).

### Configuration Example

```yaml tab="File (YAML)"
log:
  filePath: "/path/to/log-file.log"
  format: json
  level: INFO
```

```toml tab="File (TOML)"
[log]
  filePath = "/path/to/log-file.log"
  format = "json"
  level = "INFO"
```

```sh tab="CLI"
--log.filePath=/path/to/log-file.log
--log.format=json
--log.level=INFO
```

### Configuration Options

The section below describe how to configure Traefik logs using the static configuration.

| Field      | Description  | Default | Required |
|:-----------|:----------------------------|:--------|:---------|
| <a id="opt-log-filePath" href="#opt-log-filePath" title="#opt-log-filePath">`log.filePath`</a> | By default, the logs are written to the standard output.<br />You can configure a file path instead using the `filePath` option. When `filePath` is specified, Traefik will write logs only to that file (not to standard output).| - | No      |
| <a id="opt-log-format" href="#opt-log-format" title="#opt-log-format">`log.format`</a> | Log format (`common`or `json`).<br /> The fields displayed with the format `common` cannot be customized. | "common" | No      |
| <a id="opt-log-level" href="#opt-log-level" title="#opt-log-level">`log.level`</a> | Log level (`TRACE`, `DEBUG`, `INFO`, `WARN`, `ERROR`, `FATAL`, and `PANIC`)| ERROR | No      |
| <a id="opt-log-noColor" href="#opt-log-noColor" title="#opt-log-noColor">`log.noColor`</a> | When using the format `common`, disables the colorized output. | false      | No      |
| <a id="opt-log-maxSize" href="#opt-log-maxSize" title="#opt-log-maxSize">`log.maxSize`</a> | Maximum size in megabytes of the log file before it gets rotated. | 100MB      | No      |
| <a id="opt-log-maxAge" href="#opt-log-maxAge" title="#opt-log-maxAge">`log.maxAge`</a> | Maximum number of days to retain old log files based on the timestamp encoded in their filename.<br /> A day is defined as 24 hours and may not exactly correspond to calendar days due to daylight savings, leap seconds, etc.<br />By default files are not removed based on their age.  |   0   | No      |
| <a id="opt-log-maxBackups" href="#opt-log-maxBackups" title="#opt-log-maxBackups">`log.maxBackups`</a> | Maximum number of old log files to retain.<br />The default is to retain all old log files. |  0  | No      |
| <a id="opt-log-compress" href="#opt-log-compress" title="#opt-log-compress">`log.compress`</a> | Compress log files in gzip after rotation. | false | No      |

### OpenTelemetry

Traefik supports OpenTelemetry for logging. To enable OpenTelemetry, you need to set the following in the static configuration:

```yaml tab="File (YAML)"
experimental:
  otlpLogs: true
```

```toml tab="File (TOML)"
[experimental]
  otlpLogs = true
```

```sh tab="CLI"
--experimental.otlpLogs=true
```

!!! warning
    This is an experimental feature.

!!! note "Stdio logs remain available"
    When OTLP logging is enabled, standard output (stdio) logs are still available and will continue to be written alongside OTLP exports.

#### Configuration Example

```yaml tab="File (YAML)"
experimental:
  otlpLogs: true

log:
  otlp:
    http:
      endpoint: https://collector:4318/v1/logs
      headers:
        Authorization: Bearer auth_asKXRhIMplM7El1JENjrotGouS1LYRdL
```

```toml tab="File (TOML)"
[experimental]
  otlpLogs = true

[log.otlp]
  http.endpoint = "https://collector:4318/v1/logs"
  http.headers.Authorization = "Bearer auth_asKXRhIMplM7El1JENjrotGouS1LYRdL"
```

```sh tab="CLI"
--experimental.otlpLogs=true
--log.otlp.http.endpoint=https://collector:4318/v1/logs
--log.otlp.http.headers.Authorization=Bearer auth_asKXRhIMplM7El1JENjrotGouS1LYRdL
```

#### Configuration Options

| Field                                  | Description                                                                                                                            | Default                          | Required |
|:---------------------------------------|:---------------------------------------------------------------------------------------------------------------------------------------|:---------------------------------|:---------|
| <a id="opt-log-otlp-serviceName" href="#opt-log-otlp-serviceName" title="#opt-log-otlp-serviceName">`log.otlp.serviceName`</a> | Service name used in selected backend.                                                                                                 | "traefik"                        | No       |
| <a id="opt-log-otlp-resourceAttributes" href="#opt-log-otlp-resourceAttributes" title="#opt-log-otlp-resourceAttributes">`log.otlp.resourceAttributes`</a> | Defines additional resource attributes to be sent to the collector.  See [resourceAttributes](#resourceattributes) for details.                                                                    | []                               | No       |
| <a id="opt-log-otlp-http" href="#opt-log-otlp-http" title="#opt-log-otlp-http">`log.otlp.http`</a> | This instructs the exporter to send logs to the OpenTelemetry Collector using HTTP.                                                    |                                  | No       |
| <a id="opt-log-otlp-http-endpoint" href="#opt-log-otlp-http-endpoint" title="#opt-log-otlp-http-endpoint">`log.otlp.http.endpoint`</a> | The endpoint of the OpenTelemetry Collector. (format=`<scheme>://<host>:<port><path>`)                                                 | `https://localhost:4318/v1/logs` | No       |
| <a id="opt-log-otlp-http-headers" href="#opt-log-otlp-http-headers" title="#opt-log-otlp-http-headers">`log.otlp.http.headers`</a> | Additional headers sent with logs by the exporter to the OpenTelemetry Collector.                                                      | [ ]                              | No       |
| <a id="opt-log-otlp-http-tls" href="#opt-log-otlp-http-tls" title="#opt-log-otlp-http-tls">`log.otlp.http.tls`</a> | Defines the Client TLS configuration used by the exporter to send logs to the OpenTelemetry Collector.                                 |                                  | No       |
| <a id="opt-log-otlp-http-tls-ca" href="#opt-log-otlp-http-tls-ca" title="#opt-log-otlp-http-tls-ca">`log.otlp.http.tls.ca`</a> | The path to the certificate authority used for the secure connection to the OpenTelemetry Collector, it defaults to the system bundle. |                                  | No       |
| <a id="opt-log-otlp-http-tls-cert" href="#opt-log-otlp-http-tls-cert" title="#opt-log-otlp-http-tls-cert">`log.otlp.http.tls.cert`</a> | The path to the certificate to use for the OpenTelemetry Collector.                                                                    |                                  | No       |
| <a id="opt-log-otlp-http-tls-key" href="#opt-log-otlp-http-tls-key" title="#opt-log-otlp-http-tls-key">`log.otlp.http.tls.key`</a> | The path to the key to use for the OpenTelemetry Collector.                                                                            |                                  | No       |
| <a id="opt-log-otlp-http-tls-insecureSkipVerify" href="#opt-log-otlp-http-tls-insecureSkipVerify" title="#opt-log-otlp-http-tls-insecureSkipVerify">`log.otlp.http.tls.insecureSkipVerify`</a> | Instructs the OpenTelemetry Collector to accept any certificate presented by the server regardless of the hostname in the certificate. | false                            | No       |
| <a id="opt-log-otlp-grpc" href="#opt-log-otlp-grpc" title="#opt-log-otlp-grpc">`log.otlp.grpc`</a> | This instructs the exporter to send logs to the OpenTelemetry Collector using gRPC.                                                    |                                  | No       |
| <a id="opt-log-otlp-grpc-endpoint" href="#opt-log-otlp-grpc-endpoint" title="#opt-log-otlp-grpc-endpoint">`log.otlp.grpc.endpoint`</a> | The endpoint of the OpenTelemetry Collector. (format=`<host>:<port>`)                                                                  | `localhost:4317`                 | No       |
| <a id="opt-log-otlp-grpc-headers" href="#opt-log-otlp-grpc-headers" title="#opt-log-otlp-grpc-headers">`log.otlp.grpc.headers`</a> | Additional headers sent with logs by the exporter to the OpenTelemetry Collector.                                                      | [ ]                              | No       |
| <a id="opt-log-otlp-grpc-insecure" href="#opt-log-otlp-grpc-insecure" title="#opt-log-otlp-grpc-insecure">`log.otlp.grpc.insecure`</a> | Instructs the exporter to send logs to the OpenTelemetry Collector using an insecure protocol.                                         | false                            | No       |
| <a id="opt-log-otlp-grpc-tls" href="#opt-log-otlp-grpc-tls" title="#opt-log-otlp-grpc-tls">`log.otlp.grpc.tls`</a> | Defines the Client TLS configuration used by the exporter to send logs to the OpenTelemetry Collector.                                 |                                  | No       |
| <a id="opt-log-otlp-grpc-tls-ca" href="#opt-log-otlp-grpc-tls-ca" title="#opt-log-otlp-grpc-tls-ca">`log.otlp.grpc.tls.ca`</a> | The path to the certificate authority used for the secure connection to the OpenTelemetry Collector, it defaults to the system bundle. |                                  | No       |
| <a id="opt-log-otlp-grpc-tls-cert" href="#opt-log-otlp-grpc-tls-cert" title="#opt-log-otlp-grpc-tls-cert">`log.otlp.grpc.tls.cert`</a> | The path to the certificate to use for the OpenTelemetry Collector.                                                                    |                                  | No       |
| <a id="opt-log-otlp-grpc-tls-key" href="#opt-log-otlp-grpc-tls-key" title="#opt-log-otlp-grpc-tls-key">`log.otlp.grpc.tls.key`</a> | The path to the key to use for the OpenTelemetry Collector.                                                                            |                                  | No       |
| <a id="opt-log-otlp-grpc-tls-insecureSkipVerify" href="#opt-log-otlp-grpc-tls-insecureSkipVerify" title="#opt-log-otlp-grpc-tls-insecureSkipVerify">`log.otlp.grpc.tls.insecureSkipVerify`</a> | Instructs the OpenTelemetry Collector to accept any certificate presented by the server regardless of the hostname in the certificate. | false                            | No       |

#### resourceAttributes

The `resourceAttributes` option allows setting the resource attributes sent along the traces.
Traefik also supports the `OTEL_RESOURCE_ATTRIBUTES` env variable to set up the resource attributes.

!!! info "Kubernetes Resource Attributes Detection"

    Additionally, Traefik automatically discovers the following [Kubernetes resource attributes](https://opentelemetry.io/docs/specs/semconv/non-normative/k8s-attributes/) when running in a Kubernetes cluster:
    
    - `k8s.namespace.name`
    - `k8s.pod.uid`
    - `k8s.pod.name`
    
    Note that this automatic detection can fail, like if the Traefik pod is running in host network mode.
    In this case, you should provide the attributes with the option or the env variable.

## AccessLogs

Access logs concern everything that happens to the requests handled by Traefik.

### Configuration Example

```yaml tab="File (YAML)"
accessLog:
  # JSON format
  format: json
  # Filter on status codes, retry attempts and minimal duration
  filters:
    statusCodes:
      - "200"
      - "300-302"
    retryAttempts: true
    minDuration: "10ms"
  fields:
    # Keep all the fields by default
    defaultMode: keep
    names:
      # Drop the Field ClientUserName
      ClientUsername: drop
    headers:
      # Keep all the headers by default
      defaultMode: keep
      names:
        # Redact the User-Agent header value
        User-Agent: redact
        # Drop the Authorization header value
        Authorization: drop
```

```toml tab="File (TOML)"
[accessLog]
  format = "json"

  [accessLog.filters]
    statusCodes = [ "200", "300-302" ]
    retryAttempts = true
    minDuration = "10ms"

  [accessLog.fields]
    defaultMode = "keep"

    [accessLog.fields.names]
      ClientUsername = "drop"

    [accessLog.fields.headers]
      defaultMode = "keep"

      [accessLog.fields.headers.names]
        User-Agent = "redact"
        Authorization = "drop"
```

```sh tab="CLI"
--accesslog=true
--accesslog.format=json
--accesslog.filters.statuscodes=200,300-302
--accesslog.filters.retryattempts
--accesslog.filters.minduration=10ms
--accesslog.fields.defaultmode=keep
--accesslog.fields.names.ClientUsername=drop
--accesslog.fields.headers.defaultmode=keep
--accesslog.fields.headers.names.User-Agent=redact
--accesslog.fields.headers.names.Authorization=drop
```

### Configuration Options

The section below describes how to configure Traefik access logs using the static configuration.

| Field      | Description    | Default | Required |
|:-----------|:--------------------------|:--------|:---------|
| <a id="opt-accesslog-filePath" href="#opt-accesslog-filePath" title="#opt-accesslog-filePath">`accesslog.filePath`</a> | By default, the access logs are written to the standard output.<br />You can configure a file path instead using the `filePath` option.|  | No      |
| <a id="opt-accesslog-format" href="#opt-accesslog-format" title="#opt-accesslog-format">`accesslog.format`</a> | By default, logs are written using the Traefik Common Log Format (CLF).<br />Available formats: [`common`](#traefik-clf-format-fields) (Traefik extended CLF), [`genericCLF`](#generic-clf-format-fields) (standard CLF compatible with analyzers), or [`json`](#json-format-fields).<br />If the given format is unsupported, the default (`common`) is used instead. | "common" | No      |
| <a id="opt-accesslog-bufferingSize" href="#opt-accesslog-bufferingSize" title="#opt-accesslog-bufferingSize">`accesslog.bufferingSize`</a> | To write the logs in an asynchronous fashion, specify a  `bufferingSize` option.<br />This option represents the number of log lines Traefik will keep in memory before writing them to the selected output.<br />In some cases, this option can greatly help performances.| 0 | No      |
| <a id="opt-accesslog-addInternals" href="#opt-accesslog-addInternals" title="#opt-accesslog-addInternals">`accesslog.addInternals`</a> | Enables access logs for internal resources (e.g.: `ping@internal`). | false  | No      |
| <a id="opt-accesslog-filters-statusCodes" href="#opt-accesslog-filters-statusCodes" title="#opt-accesslog-filters-statusCodes">`accesslog.filters.statusCodes`</a> | Limit the access logs to requests with a status codes in the specified range. | [ ]      | No      |
| <a id="opt-accesslog-filters-retryAttempts" href="#opt-accesslog-filters-retryAttempts" title="#opt-accesslog-filters-retryAttempts">`accesslog.filters.retryAttempts`</a> | Keep the access logs when at least one retry has happened. | false      | No      |
| <a id="opt-accesslog-filters-minDuration" href="#opt-accesslog-filters-minDuration" title="#opt-accesslog-filters-minDuration">`accesslog.filters.minDuration`</a> | Keep access logs when requests take longer than the specified duration (provided in seconds or as a valid duration format, see [time.ParseDuration](https://golang.org/pkg/time/#ParseDuration)).  |  0   | No      |
| <a id="opt-accesslog-fields-defaultMode" href="#opt-accesslog-fields-defaultMode" title="#opt-accesslog-fields-defaultMode">`accesslog.fields.defaultMode`</a> | Mode to apply by default to the access logs fields (`keep`, `redact` or `drop`). | keep | No      |
| <a id="opt-accesslog-fields-names" href="#opt-accesslog-fields-names" title="#opt-accesslog-fields-names">`accesslog.fields.names`</a> | Set the fields list to display in the access logs (format `name:mode`).<br /> Available fields list [here](#json-format-fields). |  [ ]    | No      |
| <a id="opt-accesslog-fields-headers-defaultMode" href="#opt-accesslog-fields-headers-defaultMode" title="#opt-accesslog-fields-headers-defaultMode">`accesslog.fields.headers.defaultMode`</a> | Mode to apply by default to the access logs headers (`keep`, `redact` or `drop`).  | drop | No      |
| <a id="opt-accesslog-fields-headers-names" href="#opt-accesslog-fields-headers-names" title="#opt-accesslog-fields-headers-names">`accesslog.fields.headers.names`</a> | Set the headers list to display in the access logs (format `name:mode`). |   [ ]   | No      |

### OpenTelemetry

Traefik supports OpenTelemetry for access logs. To enable OpenTelemetry, you need to set the following in the static configuration:

```yaml tab="File (YAML)"
experimental:
  otlpLogs: true
```

```toml tab="File (TOML)"
[experimental]
  otlpLogs = true
```

```sh tab="CLI"
--experimental.otlpLogs=true
```

!!! warning
    This is an experimental feature.

#### Configuration Example

```yaml tab="File (YAML)"
experimental:
  otlpLogs: true

accesslog:
  otlp:
    http:
      endpoint: https://collector:4318/v1/logs
      headers:
        Authorization: Bearer auth_asKXRhIMplM7El1JENjrotGouS1LYRdL
```

```toml tab="File (TOML)"
[experimental]
  otlpLogs = true

[accesslog.otlp]
  http.endpoint = "https://collector:4318/v1/logs"
  http.headers.Authorization = "Bearer auth_asKXRhIMplM7El1JENjrotGouS1LYRdL"
```

```yaml tab="CLI"
--experimental.otlpLogs=true
--accesslog.otlp.http.endpoint=https://collector:4318/v1/logs
--accesslog.otlp.http.headers.Authorization=Bearer auth_asKXRhIMplM7El1JENjrotGouS1LYRdL
```

#### Configuration Options

| Field                                        | Description                                                                                                                            | Default                          | Required |
|:---------------------------------------------|:---------------------------------------------------------------------------------------------------------------------------------------|:---------------------------------|:---------|
| <a id="opt-accesslog-otlp-serviceName" href="#opt-accesslog-otlp-serviceName" title="#opt-accesslog-otlp-serviceName">`accesslog.otlp.serviceName`</a> | Defines the service name resource attribute.                                                                                           | "traefik"                        | No       |
| <a id="opt-accesslog-otlp-resourceAttributes" href="#opt-accesslog-otlp-resourceAttributes" title="#opt-accesslog-otlp-resourceAttributes">`accesslog.otlp.resourceAttributes`</a> | Defines additional resource attributes to be sent to the collector. See [resourceAttributes](#resourceattributes_1) for details.       | []                               | No       |
| <a id="opt-accesslog-otlp-http" href="#opt-accesslog-otlp-http" title="#opt-accesslog-otlp-http">`accesslog.otlp.http`</a> | This instructs the exporter to send access logs to the OpenTelemetry Collector using HTTP.                                             |                                  | No       |
| <a id="opt-accesslog-otlp-http-endpoint" href="#opt-accesslog-otlp-http-endpoint" title="#opt-accesslog-otlp-http-endpoint">`accesslog.otlp.http.endpoint`</a> | The endpoint of the OpenTelemetry Collector. (format=`<scheme>://<host>:<port><path>`)                                                 | `https://localhost:4318/v1/logs` | No       |
| <a id="opt-accesslog-otlp-http-headers" href="#opt-accesslog-otlp-http-headers" title="#opt-accesslog-otlp-http-headers">`accesslog.otlp.http.headers`</a> | Additional headers sent with access logs by the exporter to the OpenTelemetry Collector.                                               | [ ]                              | No       |
| <a id="opt-accesslog-otlp-http-tls" href="#opt-accesslog-otlp-http-tls" title="#opt-accesslog-otlp-http-tls">`accesslog.otlp.http.tls`</a> | Defines the Client TLS configuration used by the exporter to send access logs to the OpenTelemetry Collector.                          |                                  | No       |
| <a id="opt-accesslog-otlp-http-tls-ca" href="#opt-accesslog-otlp-http-tls-ca" title="#opt-accesslog-otlp-http-tls-ca">`accesslog.otlp.http.tls.ca`</a> | The path to the certificate authority used for the secure connection to the OpenTelemetry Collector, it defaults to the system bundle. |                                  | No       |
| <a id="opt-accesslog-otlp-http-tls-cert" href="#opt-accesslog-otlp-http-tls-cert" title="#opt-accesslog-otlp-http-tls-cert">`accesslog.otlp.http.tls.cert`</a> | The path to the certificate to use for the OpenTelemetry Collector.                                                                    |                                  | No       |
| <a id="opt-accesslog-otlp-http-tls-key" href="#opt-accesslog-otlp-http-tls-key" title="#opt-accesslog-otlp-http-tls-key">`accesslog.otlp.http.tls.key`</a> | The path to the key to use for the OpenTelemetry Collector.                                                                            |                                  | No       |
| <a id="opt-accesslog-otlp-http-tls-insecureSkipVerify" href="#opt-accesslog-otlp-http-tls-insecureSkipVerify" title="#opt-accesslog-otlp-http-tls-insecureSkipVerify">`accesslog.otlp.http.tls.insecureSkipVerify`</a> | Instructs the OpenTelemetry Collector to accept any certificate presented by the server regardless of the hostname in the certificate. | false                            | No       |
| <a id="opt-accesslog-otlp-grpc" href="#opt-accesslog-otlp-grpc" title="#opt-accesslog-otlp-grpc">`accesslog.otlp.grpc`</a> | This instructs the exporter to send access logs to the OpenTelemetry Collector using gRPC.                                             |                                  | No       |
| <a id="opt-accesslog-otlp-grpc-endpoint" href="#opt-accesslog-otlp-grpc-endpoint" title="#opt-accesslog-otlp-grpc-endpoint">`accesslog.otlp.grpc.endpoint`</a> | The endpoint of the OpenTelemetry Collector. (format=`<host>:<port>`)                                                                  | `localhost:4317`                 | No       |
| <a id="opt-accesslog-otlp-grpc-headers" href="#opt-accesslog-otlp-grpc-headers" title="#opt-accesslog-otlp-grpc-headers">`accesslog.otlp.grpc.headers`</a> | Additional headers sent with access logs by the exporter to the OpenTelemetry Collector.                                               | [ ]                              | No       |
| <a id="opt-accesslog-otlp-grpc-insecure" href="#opt-accesslog-otlp-grpc-insecure" title="#opt-accesslog-otlp-grpc-insecure">`accesslog.otlp.grpc.insecure`</a> | Instructs the exporter to send access logs to the OpenTelemetry Collector using an insecure protocol.                                  | false                            | No       |
| <a id="opt-accesslog-otlp-grpc-tls" href="#opt-accesslog-otlp-grpc-tls" title="#opt-accesslog-otlp-grpc-tls">`accesslog.otlp.grpc.tls`</a> | Defines the Client TLS configuration used by the exporter to send access logs to the OpenTelemetry Collector.                          |                                  | No       |
| <a id="opt-accesslog-otlp-grpc-tls-ca" href="#opt-accesslog-otlp-grpc-tls-ca" title="#opt-accesslog-otlp-grpc-tls-ca">`accesslog.otlp.grpc.tls.ca`</a> | The path to the certificate authority used for the secure connection to the OpenTelemetry Collector, it defaults to the system bundle. |                                  | No       |
| <a id="opt-accesslog-otlp-grpc-tls-cert" href="#opt-accesslog-otlp-grpc-tls-cert" title="#opt-accesslog-otlp-grpc-tls-cert">`accesslog.otlp.grpc.tls.cert`</a> | The path to the certificate to use for the OpenTelemetry Collector.                                                                    |                                  | No       |
| <a id="opt-accesslog-otlp-grpc-tls-key" href="#opt-accesslog-otlp-grpc-tls-key" title="#opt-accesslog-otlp-grpc-tls-key">`accesslog.otlp.grpc.tls.key`</a> | The path to the key to use for the OpenTelemetry Collector.                                                                            |                                  | No       |
| <a id="opt-accesslog-otlp-grpc-tls-insecureSkipVerify" href="#opt-accesslog-otlp-grpc-tls-insecureSkipVerify" title="#opt-accesslog-otlp-grpc-tls-insecureSkipVerify">`accesslog.otlp.grpc.tls.insecureSkipVerify`</a> | Instructs the OpenTelemetry Collector to accept any certificate presented by the server regardless of the hostname in the certificate. | false                            | No       |

#### resourceAttributes

The `resourceAttributes` option allows setting the resource attributes sent along the traces.
Traefik also supports the `OTEL_RESOURCE_ATTRIBUTES` env variable to set up the resource attributes.

!!! info "Kubernetes Resource Attributes Detection"

    Additionally, Traefik automatically discovers the following [Kubernetes resource attributes](https://opentelemetry.io/docs/specs/semconv/non-normative/k8s-attributes/) when running in a Kubernetes cluster:
    
    - `k8s.namespace.name`
    - `k8s.pod.uid`
    - `k8s.pod.name`
    
    Note that this automatic detection can fail, like if the Traefik pod is running in host network mode.
    In this case, you should provide the attributes with the option or the env variable.

### Traefik CLF format fields

It's the default format provided by Traefik.
Below the fields displayed with the Traefik CLF format:

```html
<remote_IP_address> - <client_user_name_if_available> [<timestamp>] 
"<request_method> <request_path> <request_protocol>" <HTTP_status> <content-length> 
"<request_referrer>" "<request_user_agent>" <number_of_requests_received_since_Traefik_started>
"<Traefik_router_name>" "<Traefik_server_URL>" <request_duration_in_ms>ms
```

### Generic CLF format fields

Below the fields displayed with the generic CLF format:

```html
<remote_IP_address> - <client_user_name_if_available> [<timestamp>] 
"<request_method> <request_path> <request_protocol>" <HTTP_status> <content-length> 
"<request_referrer>" "<request_user_agent>"
```

### JSON format fields

| Field                   | Description   |
|-------------------------|------------------|
| <a id="opt-StartUTC" href="#opt-StartUTC" title="#opt-StartUTC">`StartUTC`</a> | The time at which request processing started.                                                                                                                       |
| <a id="opt-StartLocal" href="#opt-StartLocal" title="#opt-StartLocal">`StartLocal`</a> | The local time at which request processing started.                                                                                                                 |
| <a id="opt-Duration" href="#opt-Duration" title="#opt-Duration">`Duration`</a> | The total time taken (in nanoseconds) by processing the response, including the origin server's time but not the log writing time.                                  |
| <a id="opt-RouterName" href="#opt-RouterName" title="#opt-RouterName">`RouterName`</a> | The name of the Traefik  router.                                                                                                                                    |
| <a id="opt-ServiceName" href="#opt-ServiceName" title="#opt-ServiceName">`ServiceName`</a> | The name of the Traefik backend.          |
| <a id="opt-ServiceURL" href="#opt-ServiceURL" title="#opt-ServiceURL">`ServiceURL`</a> | The URL of the Traefik backend.       |
| <a id="opt-ServiceAddr" href="#opt-ServiceAddr" title="#opt-ServiceAddr">`ServiceAddr`</a> | The IP:port of the Traefik backend (extracted from `ServiceURL`). |
| <a id="opt-ClientAddr" href="#opt-ClientAddr" title="#opt-ClientAddr">`ClientAddr`</a> | The remote address in its original form (usually IP:port).     |
| <a id="opt-ClientHost" href="#opt-ClientHost" title="#opt-ClientHost">`ClientHost`</a> | The remote IP address from which the client request was received.     |
| <a id="opt-ClientPort" href="#opt-ClientPort" title="#opt-ClientPort">`ClientPort`</a> | The remote TCP port from which the client request was received.   |
| <a id="opt-ClientUsername" href="#opt-ClientUsername" title="#opt-ClientUsername">`ClientUsername`</a> | The username provided in the URL, if present.   |
| <a id="opt-RequestAddr" href="#opt-RequestAddr" title="#opt-RequestAddr">`RequestAddr`</a> | The HTTP Host header (usually IP:port). This is treated as not a header by the Go API.   |
| <a id="opt-RequestHost" href="#opt-RequestHost" title="#opt-RequestHost">`RequestHost`</a> | The HTTP Host server name (not including port).     |
| <a id="opt-RequestPort" href="#opt-RequestPort" title="#opt-RequestPort">`RequestPort`</a> | The TCP port from the HTTP Host.    |
| <a id="opt-RequestMethod" href="#opt-RequestMethod" title="#opt-RequestMethod">`RequestMethod`</a> | The HTTP method. |
| <a id="opt-RequestPath" href="#opt-RequestPath" title="#opt-RequestPath">`RequestPath`</a> | The HTTP request URI, not including the scheme, host or port.   |
| <a id="opt-RequestProtocol" href="#opt-RequestProtocol" title="#opt-RequestProtocol">`RequestProtocol`</a> | The version of HTTP requested.       |
| <a id="opt-RequestScheme" href="#opt-RequestScheme" title="#opt-RequestScheme">`RequestScheme`</a> | The HTTP scheme requested `http` or `https`.   |
| <a id="opt-RequestLine" href="#opt-RequestLine" title="#opt-RequestLine">`RequestLine`</a> | The `RequestMethod`, + `RequestPath` and `RequestProtocol`.   |
| <a id="opt-RequestContentSize" href="#opt-RequestContentSize" title="#opt-RequestContentSize">`RequestContentSize`</a> | The number of bytes in the request entity (a.k.a. body) sent by the client.   |
| <a id="opt-OriginDuration" href="#opt-OriginDuration" title="#opt-OriginDuration">`OriginDuration`</a> | The time taken (in nanoseconds) by the origin server ('upstream') to return its response. |
| <a id="opt-OriginContentSize" href="#opt-OriginContentSize" title="#opt-OriginContentSize">`OriginContentSize`</a> | The content length specified by the origin server, or 0 if unspecified.    |
| <a id="opt-OriginStatus" href="#opt-OriginStatus" title="#opt-OriginStatus">`OriginStatus`</a> | The HTTP status code returned by the origin server. If the request was handled by this Traefik instance (e.g. with a redirect), then this value will be absent (0). |
| <a id="opt-OriginStatusLine" href="#opt-OriginStatusLine" title="#opt-OriginStatusLine">`OriginStatusLine`</a> | `OriginStatus` + Status code explanation   |
| <a id="opt-DownstreamStatus" href="#opt-DownstreamStatus" title="#opt-DownstreamStatus">`DownstreamStatus`</a> | The HTTP status code returned to the client.    |
| <a id="opt-DownstreamStatusLine" href="#opt-DownstreamStatusLine" title="#opt-DownstreamStatusLine">`DownstreamStatusLine`</a> | The `DownstreamStatus` and status code explanation.     |
| <a id="opt-DownstreamContentSize" href="#opt-DownstreamContentSize" title="#opt-DownstreamContentSize">`DownstreamContentSize`</a> | The number of bytes in the response entity returned to the client. This is in addition to the "Content-Length" header, which may be present in the origin response. |
| <a id="opt-RequestCount" href="#opt-RequestCount" title="#opt-RequestCount">`RequestCount`</a> | The number of requests received since the Traefik instance started.    |
| <a id="opt-GzipRatio" href="#opt-GzipRatio" title="#opt-GzipRatio">`GzipRatio`</a> | The response body compression ratio achieved.   |
| <a id="opt-Overhead" href="#opt-Overhead" title="#opt-Overhead">`Overhead`</a> | The processing time overhead (in nanoseconds) caused by Traefik.    |
| <a id="opt-RetryAttempts" href="#opt-RetryAttempts" title="#opt-RetryAttempts">`RetryAttempts`</a> | The amount of attempts the request was retried.   |
| <a id="opt-TLSVersion" href="#opt-TLSVersion" title="#opt-TLSVersion">`TLSVersion`</a> | The TLS version used by the connection (e.g. `1.2`) (if connection is TLS).   |
| <a id="opt-TLSCipher" href="#opt-TLSCipher" title="#opt-TLSCipher">`TLSCipher`</a> | The TLS cipher used by the connection (e.g. `TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA`) (if connection is TLS).      |
| <a id="opt-TLSClientSubject" href="#opt-TLSClientSubject" title="#opt-TLSClientSubject">`TLSClientSubject`</a> | The string representation of the TLS client certificate's Subject (e.g. `CN=username,O=organization`).  |

### Log Rotation

Traefik close and reopen its log files, assuming they're configured, on receipt of a USR1 signal.
This allows the logs to be rotated and processed by an external program, such as `logrotate`.

!!! warning
    This does not work on Windows due to the lack of USR signals.

### Time Zones

Traefik will timestamp each log line in UTC time by default.

It is possible to configure the Traefik to timestamp in a specific timezone by ensuring the following configuration has been made in your environment:

1. Provide time zone data to `/etc/localtime` or `/usr/share/zoneinfo` (based on your distribution) or set the environment variable TZ to the desired timezone.
2. Specify the field `StartLocal` by dropping the field named `StartUTC` (available on the default Common Log Format (CLF) as well as JSON): `accesslog.fields.names.StartUTC=drop`.

Example utilizing Docker Compose:

```yaml
services:
  traefik:
    image: traefik:v3.5
    environment:
      - TZ=US/Alaska
    command:
      - --accesslog.fields.names.StartUTC=drop
      - --providers.docker
    ports:
      - 80:80
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
```

{!traefik-for-business-applications.md!}
