Thank you for your patience! On Thursday, July 16, 2026, we released Mackerel's log feature as an open beta.
For background on this release, please check out our earlier announcement post.
In this post, we’ll cover terms of use, key capabilities, log setup steps, and our plans for General Availability (GA).
Table of Contents
- Beta Eligibility and Terms of Use
- What You Can Do with the Log Feature
- Filtering Structured Logs from the UI
- Save Search Conditions and Share Them with Your Team
- Team Search History
- How to Send Logs
- A Note on Sensitive Information in Logs
- Upcoming GA and Pricing
- Moving from Beta to GA
- Requesting Your Feedback
- Planned Feature Enhancements
- Upcoming Events
- In Closing
Beta Eligibility and Terms of Use
Eligible Accounts
The beta is available to essentially any Mackerel customer. This applies whether you're on the Free plan or the Standard plan (including its Trial).
However, there are some environments where the feature cannot be used — for example, contracts made through our Partner Program. (This will remain the case in the GA as well.)
Pricing During the Beta
There are no charges for using the log feature during the beta period. We will not retroactively bill for logs sent during the beta after the GA either.
Getting Started
Once logged in to Mackerel, click "Logs" in the sidebar to access the feature. For initial setup, please refer to the "How to Send Logs" section below.
From there, click "Start log search" to open the search screen.
Limitations During the Beta
We haven't placed any feature restrictions on the beta. As mentioned below, the log retention period for GA will be 30 days, and you can try the beta under those same conditions.
A few things to keep in mind during the open beta:
- We do not guarantee log data retention during the beta
- We may perform unscheduled maintenance to make improvements or fix issues
- We may throttle log ingestion for organizations sending excessive data
- Data may be lost due to unscheduled maintenance or other issues
What You Can Do with the Log Feature
Narrow Down Logs by Service
On the log search screen, you start by choosing a target service and then progressively narrow the results. It's designed to help you find the logs you need without writing queries.
Here’s how it works:
1. Select a Service
Services are identified by the combination of OpenTelemetry's service.namespace and service.name. This means that even if logs are sent from multiple systems, you can distinguish which system and service produced them.
2. Enter a Message to Search For
To search for specific text in the log body, enter it in the "Message" field. This is useful when you have some idea of what the log content looks like. If you leave it empty, all logs for the selected service are shown. For structured logs sent as JSON, you can also search by specifying combinations of field names and values.
3. Select Log Levels
You can narrow results using the log level (severity) attached to each log. By default, ERROR and WARN are selected, since those are what you'll most often check during incident response. Logs without any level information appear in results as UNSPECIFIED.
Filtering Structured Logs from the UI
For structured logs sent as JSON, you can build search conditions just by picking attributes and values on screen. It comes in handy when you want to see only logs with a specific attribute value — no query writing required.
Save Search Conditions and Share Them with Your Team
Once you've arrived at a useful set of search conditions, you can name and save them. Saved searches are shared within your team, so other members can bring up the same conditions with a single click.
Team Search History
Even without saving, searches you or your teammates run are kept as team search history. When you want to retrace the conditions someone was looking at yesterday, you can pull them up from the history.
How to Send Logs
Logs are sent to Mackerel using OpenTelemetry, routed via an OpenTelemetry Collector. There are two ways to set this up:
- Using the OTel log bridge or OTel SDK: Logs emitted by your application are sent through an OTel log bridge or SDK to the OpenTelemetry Collector, which then forwards them to Mackerel.
- Reading log files: Log files that are already being written can be picked up by an OpenTelemetry Collector receiver and forwarded to Mackerel.
It's certainly possible to send logs directly from your application to Mackerel without an OpenTelemetry Collector. In practice, however, requirements like filtering out unnecessary information or masking sensitive data tend to come up, and handling these transformations centrally in the Collector keeps your application code simpler. For that reason, we generally recommend the Collector-based configuration.
If you're already using OpenTelemetry, you can adopt this by adding an exporter to your Collector. Setup steps and supported formats are covered in detail on the help page (currently in Japanese).
A Note on Sensitive Information in Logs
Whether you’re using the beta or the GA version, please ensure logs sent to Mackerel do not contain sensitive data, such as personal information or credentials. Since logs become searchable and accessible across your entire team, it’s important to prevent sensitive information from being shared unintentionally.
With a Collector-based setup, you can apply filtering or transformations at the Collector before logs are sent, allowing you to strip out sensitive information. See ”Optimizing Log Volume with Filtering and Sampling" (currently in Japanese) for details on how to configure this.
Upcoming GA and Pricing
GA Schedule
We’re targeting fall 2026 for the GA of Mackerel’s log feature. We’ll continue refining it based on your feedback during the beta period.
Pricing
Upon GA, pricing will be ingestion-based, calculated from the volume of log data ingested by Mackerel. The rate is 70 JPY per GB (excluding tax)*1*2, and you are billed solely on the ingested volume.
There are no charges for data stored in Mackerel or query execution, such as searching logs..
Plan Eligibility
After GA, log feature availability will vary by plan.
Trial Period
Newly created organizations get a two-week free trial with functionality equivalent to the Standard plan. During this period, you can send up to 1 TB of logs.
If you don’t subscribe to the Standard plan during the trial, your organization will transition to the Free plan when the trial ends.
Free Plan
You can send up to 1 GB of logs per month. The retention period is 30 days, the same as on the Standard plan.
When transitioning from the trial or Standard plan to the Free plan, the following rules apply:
- Logs sent before the transition remain viewable until the end of their 30-day retention period, even if they exceed 1 GB.
- If you have already sent 1 GB or more during the transition month, you cannot send additional logs for the remainder of that month. Starting the following month, you'll be able to send up to 1 GB per month as usual.
Standard Plan
The Standard plan has none of the volume caps that apply to trials or the Free plan. That said, if we detect an exceptionally large volume of log data being sent, we may impose limits on log ingestion for that organization.
Regarding pricing, the log feature has no free allowance and is subject to the minimum monthly charge. If you’re only sending logs — with no host registrations or span submissions — and your total ingestion fee falls below the minimum monthly charge of 2,180 JPY (tax included), you will be billed the minimum charge of 2,180 JPY.
Moving from Beta to GA
A few things will change when Mackerel’s log feature transitions from beta to GA, while others will carry over as-is.
What Stays the Same
- Log retention is 30 days in both the beta and GA.
- Logs sent during the beta remain viewable after GA, as long as they are within the retention period.
- Saved searches carry over as-is.
What Changes
- Logs ingested after GA will be subject to volume-based charges (70 JPY/GB, excluding tax).
- Monthly volume limits and minimum charge conditions will vary by plan (see "Plan Eligibility" above).
How to Continue Using the Feature
If you’d like to continue using the feature after GA, no special steps are required. Keep sending logs as you have been, and your usage will seamlessly transition to GA. On the Standard plan, logs ingested from the GA date onward become billable. During the trial period and on the Free plan, ingestion isn’t billed; however, as noted above, log ingestion stops once the volume cap is reached.
How to Discontinue Use
If you are on the Standard plan and do not wish to use the log feature after GA, please stop sending logs during the beta period. Please note that any logs ingested on or after the GA date will be billable.
Requesting Your Feedback
One reason we're releaseing this beta is that we want to improve the feature while listening to the people actually using it. If anything stands out to you, we'd love to hear about it.
We'd especially welcome your thoughts on the following:
- Whether searching and filtering worked the way you expected
- Whether saving and sharing searches helped with team investigations
- Any missing functionality or use cases you'd like to see supported
Please send feedback through our contact form. The development team reviews everything we receive.
Planned Feature Enhancements
Some features were not included in the beta release, but we plan to add them going forward. Please note that the following features are currently at the conceptual stage and do not represent a final commitment.
- Creating alerts from logs: Configure rules that trigger Mackerel alerts when logs contain specified text.
- Tracing from alerts to related logs: View related logs directly from the alert screen when a log-based alert triggers.
- Accessing logs via an MCP server: Access Mackerel logs through an MCP server alongside the existing public API.
We will determine priorities and specific release timelines based on the feedback we receive during the beta.
Upcoming Events
To coincide with the GA release of the log feature, we are planning to host and participate in several events.
In Closing
With Mackerel's log feature, we aim to turn log investigation — which has often relied on individual experience — into something a whole team can consistently reproduce. Today's open beta release is the first step!
Please give it a try and let us know your thoughts and what you’d like to see improved. With your feedback, we’ll keep refining the feature as we head toward GA.
