Hello, this is Mackerel team CRE's 
id:kmuto . I'm pleased to share the details of this update.
- Service Map is introduced and now visually indicates errors occurring in APM-monitored services
- A configuration has been added to mackerel-container-agent to enable it to run with a read-only root filesystem
- Debian 13 Trixie has been added to the list of supported operating systems for mackerel-agent
- The mackerel-plugin-snmp plugin now allows specifying custom port numbers
- AWS plugins have been removed from the mackerel-agent-plugins bundle
- [Future Update] Changes to Numerical Representation in Alert Notifications
- Go Conference 2025 is just around the corner. Hatena is sponsoring as a Silver Sponsor, and Mackerel will be exhibiting at a booth
Service Map is introduced and now visually indicates errors occurring in APM-monitored services
Mackerel's APM feature displays separate screens for each service. Consequently, even when dependencies existed between services, it was hard to discern these connections.
The newly added Service Map feature displays services (components) directly dependent on the service being viewed when a trace includes spans from different services. Furthermore, clicking on a displayed service name allows navigation to that service's APM screen.
This Service Map has been further enhanced to display arrows in red when an error occurs in either the calling service or the called service.
We will continue to improve the Service Map towards the general release, so please do use it and send us your feedback!
A configuration has been added to mackerel-container-agent to enable it to run with a read-only root filesystem
One approach for enhancing container security on Amazon ECS is to enable the read-only root filesystem (readonlyRootFilesystem) setting. However, mackerel-container-agent writes the host ID to a file, meaning enabling this setting caused the container to fail to start.
To resolve this, a configuration option has been added to store the host ID in memory instead of a file. From mackerel-container-agent v0.12.0 onwards, you can switch the storage location for the host ID using either the environment variable MACKEREL_HOST_ID_STORE or the hostIdStore parameter in the configuration YAML file.
file: Writes to a file as before (default)memory: Stores in memory
Please note that this update only affects the host ID and does not include support for plugins that write to files.
Debian 13 Trixie has been added to the list of supported operating systems for mackerel-agent
Debian 13 (codename Trixie), released on 9 August 2025, has been added to the list of supported operating systems for mackerel-agent.
For the environments currently supported by Mackerel and mackerel-agent, please refer to the Supported Environments.
The mackerel-plugin-snmp plugin now allows specifying custom port numbers
The mackerel-plugin-snmp plugin converts values retrieved via SNMP from SNMP agents on network devices into metrics. This plugin previously required the target SNMP agent to be exposed on UDP port 161. To accommodate agents exposed on other ports, we introduced --port option.
This feature is included in mackerel-agent-plugins v0.89.0.
AWS plugins have been removed from the mackerel-agent-plugins bundle
As previously announced on 25 July 2025, from mackerel-agent-plugins v0.89.0 onwards, we will no longer include AWS-related plugins.
The excluded plugins are listed below. Equivalent functionality is provided via the AWS Integration, which we recommend you utilise instead. The mackerel-plugin-aws-ec2-ebs plugin remains included as an alternative via the AWS Integration is difficult to achieve.
- https://github.com/mackerelio/mackerel-plugin-aws-cloudfront
- https://github.com/mackerelio/mackerel-plugin-aws-dynamodb
- https://github.com/mackerelio/mackerel-plugin-aws-ec2-cpucredit
- https://github.com/mackerelio/mackerel-plugin-aws-elasticache
- https://github.com/mackerelio/mackerel-plugin-aws-elasticsearch
- https://github.com/mackerelio/mackerel-plugin-aws-elb
- https://github.com/mackerelio/mackerel-plugin-aws-kinesis-streams
- https://github.com/mackerelio/mackerel-plugin-aws-lambda
- https://github.com/mackerelio/mackerel-plugin-aws-rds
- https://github.com/mackerelio/mackerel-plugin-aws-s3-requests
- https://github.com/mackerelio/mackerel-plugin-aws-ses
You may continue to download and use the software from the individual repository, but please understand that it is no longer subject to future development.
[Future Update] Changes to Numerical Representation in Alert Notifications
When alert messages previously contained extremely large numbers such as "10000000.123", they were displayed using an exponential notation like "1.000000013E7", which was difficult to understand. To improve this, we will soon implement the following changes to numerical representation:
- Numerical values will no longer be expressed in exponential notation
- Previously, decimal places were rounded up; in the future, decimal places beyond the third decimal place will be truncated
- Previously, one decimal place was always displayed; in the future, if the decimal places are zero, the decimal point will not be shown
| Value | Previous display | Future display |
|---|---|---|
| 100.123 | 100.13 | 100.12 |
| 10000000.123 | 1.000000013E7 | 10000000.12 |
| 1000000.0001 | 1000000.01 | 1000000 |
| 8.0 | 8.0 | 8 |
This change affects all notification messages that report metric values. Please note that if your system is integrated with one that parses alert message values, this may have an impact.
Go Conference 2025 is just around the corner. Hatena is sponsoring as a Silver Sponsor, and Mackerel will be exhibiting at a booth
We Hatena will be sponsoring Go Conference 2025 as a Silver Sponsor, and Mackerel will be exhibiting at a booth. The event will be held at Abema Towers in Shibuya from Saturday 27th to Sunday 28th September 2025.
