Amazon CloudWatch
Send logs and metrics to Amazon CloudWatch
The Amazon CloudWatch output plugin allows to ingest your records into the CloudWatch Logs service. Support for CloudWatch Metrics is also provided via EMF.
This is the documentation for the core Fluent Bit CloudWatch plugin written in C. It can replace the aws/amazon-cloudwatch-logs-for-fluent-bit Golang Fluent Bit plugin released last year. The Golang plugin was named cloudwatch
; this new high performance CloudWatch plugin is called cloudwatch_logs
to prevent conflicts/confusion. Check the amazon repo for the Golang plugin for details on the deprecation/migration plan for the original plugin.
Configuration Parameters
Key | Description |
region | The AWS region. |
log_group_name | The name of the CloudWatch Log Group that you want log records sent to. |
log_stream_name | The name of the CloudWatch Log Stream that you want log records sent to. |
log_stream_prefix | Prefix for the Log Stream name. The tag is appended to the prefix to construct the full log stream name. Not compatible with the log_stream_name option. |
log_key | By default, the whole log record will be sent to CloudWatch. If you specify a key name with this option, then only the value of that key will be sent to CloudWatch. For example, if you are using the Fluentd Docker log driver, you can specify |
log_format | |
role_arn | ARN of an IAM role to assume (for cross account access). |
auto_create_group | Automatically create the log group. Valid values are "true" or "false" (case insensitive). Defaults to false. |
log_retention_days | If set to a number greater than zero, and newly create log group's retention policy is set to this many days. Valid values are: [1, 3, 5, 7, 14, 30, 60, 90, 120, 150, 180, 365, 400, 545, 731, 1827, 3653] |
endpoint | Specify a custom endpoint for the CloudWatch Logs API. |
metric_namespace | An optional string representing the CloudWatch namespace for the metrics. See |
metric_dimensions | |
sts_endpoint | Specify a custom STS endpoint for the AWS STS API. |
Getting Started
In order to send records into Amazon Cloudwatch, you can run the plugin from the command line or through the configuration file:
Command Line
The cloudwatch plugin, can read the parameters from the command line through the -p argument (property), e.g:
Configuration File
In your main configuration file append the following Output section:
Worker support
Fluent Bit 1.7 adds a new feature called workers
which enables outputs to have dedicated threads. This cloudwatch_logs
plugin has partial support for workers. The plugin can support a single worker; enabling multiple workers will lead to errors/indeterminate behavior.
Example:
If you enable a single worker, you are enabling a dedicated thread for your CloudWatch output. We recommend starting without workers, evaluating the performance, and then enabling a worker if needed. For most users, the plugin can provide sufficient throughput without workers.
Metrics Tutorial
Fluent Bit has different input plugins (cpu, mem, disk, netif) to collect host resource usage metrics. cloudwatch_logs
output plugin can be used to send these host metrics to CloudWatch in Embedded Metric Format (EMF). If data comes from any of the above mentioned input plugins, cloudwatch_logs
output plugin will convert them to EMF format and sent to CloudWatch as JSON log. Additionally, if we set json/emf
as the value of log_format
config option, CloudWatch will extract custom metrics from embedded JSON payload.
Note: Right now, only cpu
and mem
metrics can be sent to CloudWatch.
For using the mem
input plugin and sending memory usage metrics to CloudWatch, we can consider the following example config file. Here, we use the aws
filter which adds ec2_instance_id
and az
(availability zone) to the log records. Later, in the output config section, we set ec2_instance_id
as our metric dimension.
The following config will set two dimensions to all of our metrics- ec2_instance_id
and az
.
AWS for Fluent Bit
Amazon distributes a container image with Fluent Bit and these plugins.
GitHub
github.com/aws/aws-for-fluent-bit
Amazon ECR Public Gallery
Our images are available in Amazon ECR Public Gallery. You can download images with different tags by following command:
For example, you can pull the image with latest version by:
If you see errors for image pull limits, try log into public ECR with your AWS credentials:
You can check the Amazon ECR Public official doc for more details
Docker Hub
Amazon ECR
You can use our SSM Public Parameters to find the Amazon ECR image URI in your region:
For more see the AWS for Fluent Bit github repo.
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