Mackerel blog #mackerelio

The Official Blog of Mackerel

Regarding the policy for adding new user permissions

I’m id:daiksy, the director of Mackerel. Thank you for choosing Mackerel.

This is an announcement regarding Mackerel user permissions and our plans to add new permissions within the next few days.

Regarding the addition of user permissions

Up until now there have been three user permissions; “Owner”, “Editor”, and “Viewer”. We will be adding a new user permission to these existing three. Accordingly, each permission name can be used more conveniently as “Owner”, “Manager”, “Collaborator”, and “Viewer”. Continue reading below for a summarized explanation of the changes for permissions before and after refinement.

Permission changes before and after refinement

In Mackerel, there have been three configurable permissions in order of strength; “Owner”, “Editor”, and “Viewer”. By allowing only the necessary permissions to the user, this feature offers the ability to prevent misoperations etc. However, because the “Editor” permission also has the ability to create and edit the API key, we’ve received numerous requests asking for one more weaker permission that also has the ability to edit monitoring configurations, notification channels, etc.

Therefore, we’ve changed the three user authorities from “Owner”, “Editor” and “Viewer” to “Owner”, “Manager”, “Collaborator” and “Viewer”. This gives the user the ability to configure permissions in more detail. The names of each user authority before and after the change are listed below.

Before change After change
Owner Owner
Editor Manager
Viewer Viewer

“Editor” will be renamed “Manager” and the permissions granted are mentioned below. “Collaborator” is the newly established user authority. There has been no change to “Owner” and “Viewer”.

There is only one “Owner” per organization. However, multiple names can be registered for other permissions.

Regarding the new permissions granted with “Manager”

Currently, deletion of an API key can only be done by the “Owner”. The “Editor” does not have the authority to delete the API key. Taking use cases into consideration, having more than one person with deletion authority could allow for a quicker response, say if the API key were to be leaked etc. For this reason, both “Owner” and “Manager” permissions will have API key deletion authority.

In the event that an API key is deleted, information detailing who deleted which key will be sent via mail to anyone with Manager authority or higher

Regarding the extent of authority for “Collaborator”

Collaborators are users who are not authorized to view the API key or add members. For more details, please refer to the post-release help page.

Regarding the transition to managing new permissions

There are no required operations in particular regarding the management of new permissions. Editors up until this point will automatically be changed to Managers. As for the newly established “Collaborator”, please perform the appropriate changes after the release.

Mackerel Meetup #10 in the books/Addition of uWSGI vassal plugin etc.

Hello! Mackerel sales engineer Inoue (id:a-know) here.

Yesterday, a lot of Mackerel users came to Microsoft’s lovely venue and joined us for the 10th Mackerel Meetup!

We started off the event with Mackerel producer Sugiyama (id:sugiyama88) talking about “Microsoft Azure Integration” and “Improving Windows support”. After that, MTI presenters talked about “Key points to monitoring Azure infrastructure with Mackerel” and presenters from Future Architect talked about “Vulnerability detection tools・Vuls and Mackerel integration concepts”. We also ran 5 lightning talks! Hopefully, everyone who attended the event was able to come away with something.

A huge shout-out to Microsoft for sharing such a great venue, to the presenters, and to all of our users who attended! The entire Mackerel team thanks you.

Keep your eyes open for the Mackerel Meetup #10 event report in a separate blog coming soon!

Anyways, here is this week’s update information.

Addition of uWSGI vassal plugin

mackerel-agent-plugins 0.27.0 was released and the uWSGI vassal plugin has been added.

By using this plugin, metrics from the uWSGi server ran application (vassal) can easily be obtained with Mackerel. Yesterday, Hatena web operation engineer and the developer of this plugin id:kizkoh even made an announcement about it at the Mackerel Meetup.

Please note that you need to specify the uWSGI server --stats option to use this plugin.

Updates for mackerel-agent and more

In addition to mackerel-agent-plugins, the following updates were also made.


v0.42.3 has been released.

  • [Windows] Log output levels of the agent have been adjusted


v0.10.1 has been released.

  • Minor adjustments were made

【Notice】Regarding plans to change certain behaviors of the URL external monitor feature

Another announcement was made here this past Monday about plans to change behaviors regarding URL external monitoring response body checks and redirects. For those of you who have not checked the article, please do so.

Current specifications of the URL outline monitor feature and future plans are stated in the above article.

Mackerel booth at the Spring Cloud Computing EXPO

Mackerel is scheduled to run a booth at the “Cloud Computing EXPO · Spring” to be held from Wednesday, May 10th through Friday the 12th!

- クラウド コンピューティング EXPO | リードエグジビションジャパン (Japanese only)

I’ll be in the booth all three days, so if you’d like to talk about Mackerel or if you’re interested in hearing about what went down at the Meetup, by all means, stop on by!

Our next update blog will be on Friday, May 12th

Well, Golden Week (a Japanese holiday) is finally here. The Mackerel development team will be taking next week off, but I’m sure some people will be taking as much as 9 days off for some well deserved vacation.

Our next update announcement is scheduled for Friday, May 12th. Thank you for choosing Mackerel.

Regarding response body checks and redirects of URL external monitoring and future plans

Mackerel Sub-producer id:Songmu here. Thank you very much for choosing Mackerel. This is an announcement regarding the titled subject matter.

As stated in the help page, 2xx / 3xx type status codes are considered normal in the URL external monitor feature. Additionally, redirects are not checked for 3xx type responses.

Even if “response body check” is configured, it will not be performed if the response type is 3xx. Thus, if you currently have monitoring set up for URLs that return 3xx responses, the response body check is not being performed.

We realize this behavior is not intuitive, and we plan to change it so that if “response body check” is configured, the string will be checked even for 3xx responses.

In this case, we plan on performing string checks for the response body of 3xx type HTTP responses. The URL external monitoring feature checks the HTTP response by itself in order to not follow the redirect.

As an example, returns the 301 redirect to The output appears as shown below when accessed with curl (the output is abbreviated).

% curl -v
> GET / HTTP/1.1
> Host:
> User-Agent: curl/7.51.0
> Accept: */*
< HTTP/1.1 301 Moved Permanently
< Date: Thu, 20 Apr 2017 10:28:57 GMT
< Content-Type: text/html
< Content-Length: 178
< Connection: keep-alive
< Location:
<head><title>301 Moved Permanently</title></head>
<body bgcolor="white">
<center><h1>301 Moved Permanently</h1></center>

In this case, the section beginning with <html> will be the response body of this HTTP response, and the string check of the “response body check” will be done for this content.

Such being the case, please take a moment to review the settings concerning monitoring items which configure the “response body check” in the URL that returns 3xx type responses. Specifically, any of the following responses are assumed. If such a configuration is already set, changing the configuration is not necessary.

  • Configuring the URL to that which returns 2xx instead of 3xx
  • Deleting the “response body check” configuration
  • Configuring “response body check” for the string included in the 3xx response itself in preparation for future specification changes

We are also considering creating a configuration option in future feature expansions to follow and check the redirect for 3xx responses.


  • Currently, response body checks are not performed for 3xx type responses
  • We plan to make changes so that the response body of the original response is checked
    • Please update the configuration as necessary
  • We are considering adding options in future feature expansions to follow 3xx type redirects

Thanks again for choosing Mackerel.

Updates for mackerel-agent and mackerel-agent-plugins/A portion of OS support has been stopped etc.

The view of outside from the window has become completely green. How about for all of our Mackerel users out there?

And It’s about that time when this year’s new employees start getting used to work life.

Recently, Mastodon has been a really hot topic in Japan! Setting aside how it’s used, you could learn a lot from building your own Mastodon instance. If you do build one, be sure to monitor the server with Mackerel!

Anyways, here is this week’s update information.

Updates for mackerel-agent and mackerel-agent-plugins

Updates have been made for mackerel-agent and mackerel-agent-plugins. The specifics are listed below.

mackerel-agent v0.42.2

  • Included in mackerel-agent for Windows, the line endings of mackerel-agent.conf were set to CRLF
    • This makes editing possible even in Windows’ standard Notepad etc.
  • Other minor modifications

mackerel-agent-plugins v0.26.0

  • mackerel-plugin-aws-kinesis-streams was added
  • mackerel-plugin-aws-lambda was added
  • an error in the mackerel-plugin-redis metric label was corrected
  • mackerel-plugin-twemproxy now supports twemproxy v0.3

Thank you to everyone who contributed pull requests to the GitHub repository!

The deadline to apply for Mackerel Meetup #10 is approaching!

Tomorrow is the last day to apply for Mackerel Mackerel Meetup #10 and join us in celebrating our 10th Mackerel Meetup!

Due to it’s popularity, we’ve increased the maximum number of spots available from 70 to 80! And although all applicants will be selected through a lottery process, you’ve got a really good chance, so definitely apply!

OS Support stoppage notice

Along with the suspension of OS support, Mackerel plans to stop OS support for the following as of next month (May 2017).

  • CentOS5
  • Debian6
  • Ubuntu12.04

Even with support suspended, we do not anticipate any problems such as mackerel-agent suddenly freezing or server monitoring going down. Additionally, there are no plans to delete package repositories etc. at the moment. However, we can not guarantee that mackerel-agent will run with future updates.

We will make another announcement when support is officially stopped.

From now on as well, Mackerel plans to stop OS support according to the support end date of each OS. Regarding the supported environments of Mackerel and mackerel-agent, please refer to the following page.

Threshold input fields can now be seen upon first view when creating monitoring rules etc.

Hey! Mackerel sales engineer Inoue (id:a-know) here.

Just when I think that the spring weather will stay warm, a cold and windy day takes me by surprise. This season is really difficult to dress for…

But Golden Week (a Japanese holiday) is just around the corner and when that’s over, it’ll start to feel a lot like summer. So if you think about it like that, we should try and fully appreciate spring while it lasts.

Anyways, here is this week’s update information.

Threshold input fields can now be seen upon first view when creating monitoring rules

We made this feature update based on feedback that we received that expressed wanting to have threshold configuration in first view since it changes at a high frequency. With this, it is easier to make changes and understand the purpose/options available from this screen. Be sure to check it out.

The font set has been changed

With an aim to improve character visibility/readability, Mackerel designers tested out a variety of fonts in various environments and implemented a new font.

The following image is an side-by-side comparison using a section of the side menu. The left side is the previously used font and the right side is the updated version.

The scroll bar display has been improved

In Webkit browsers, scroll bars are not initially displayed even in areas that can be scrolled. Up until now, scroll bars appear upon scrolling. We felt this gave the interface a simpler aesthetic, but the Mackerel designers thought that it might be better to be able to see which areas can be scrolled in advance.

We vigorously discussed within issues, pull requests, etc. and as a result, we decided to make scroll bars visible when hovering the cursor over areas that are constantly displayed and always show for areas that are added afterwards.

Here at Mackerel, we are making more improvements than ever in order to be easier to understand and easier to use. Look forward to future UI improvements as well!

Release of mackerel-agent v0.42.1

mackerel-agent has been updated. The following change has been made.

  • Locale information( LC_ALL=C )will now be configured when initializing the agent

Now accepting applications for Mackerel Meetup #10!

As an official Mackerel event, we are commemorating the 10th Mackerel Meetup. We are now accepting applications!

This time we’ll be borrowing the lovely venue of Microsoft Japan!

We’ve got all sorts of things lined up! The main content for the event is as follows.

Time Title Speaker・MC
19:20-19:30 Important points in advance Hatena
19:30-19:50 Microsoft Azure Integration and Strengthening Windows Support Hatena Co., Ltd.
Mackerel Producer, Hiromichi Sugiyama(id:sugiyama88)
19:50-20:10 MTI Healthcare platform supported by Mackerel + Azure MTI Ltd.
Norio Akama
20:10-20:30 Introducing Vuls vulnerability scanner and exploring vulnerability management using Mackerel metadata Future Architect Co., Ltd.
Vuls Developer, Kota Kanbe
20:30-20:40 Questionnaire and get-together preparation time Hatena
20:40-22:00 Get-together・LT tournament Hatena・LT Presenters

With Vuls in cooperation with Microsoft Azure, this is an event you definitely don’t want to miss!

Monitoring rules that correspond to alerts have become easier to identify etc.

Hello. Sales engineer id:Soudai here.

Spring is in full bloom and I’ve noticed a lot of people who have recently started working walking beneath the cherry blossoms. It reminds me of my original intentions with joining Mackerel of showing everyone just how amazing it is.

Anyways, here is this week’s update information.

Monitoring rules that correspond to alerts have become easier to identify

When an alert occurs, it is now easier to identify for which monitoring rule the alert is occurring from the host details screen. An example is shown below.

Normally, “Monitors” are displayed in the host details like the image below.

Using the configured monitoring rules in the images above as an example, when the threshold defined by “CPU %” is exceeded, the corresponding monitoring rule will be displayed at the top of the list as shown below.

This way, even if an alert occurs for a host with many monitoring rules, it’s easier to quickly figure out for which monitoring rule the alert is occurring.

Mackerel continues to work on updates that will improve everyday utility.

Updates for the agent, plugins, and more

mackerel-agent v0.42.0

  • minor corrections were made

mackerel-agent-plugins v0.25.6

  • minor corrections were made

go-check-plugins v0.10.0 / mkr v0.15.0

  • you can now build with Go 1.8

Mackerel to participate as a silver sponsor for AWS Summit Tokyo 2017

Mackerel will participate as a silver sponsor at the AWS Summit Tokyo 2017 which will be held from May 30th (Tue) to June 2nd (Fri) 2017.

AWS Summit Tokyo 2017(2017年5月30日~6月2日)|AWS (Japanese only)

協賛スポンサー一覧 - AWS Summit Tokyo 2017(2017年5月30日~6月2日)|AWS (Japanese only)

Mackerel will be running a booth throughout the four day event.

If any of you out there have questions concerning topics like “How to monitor with AWS” and “How Mackerel works”, by all means, please stop by the Mackerel booth!

Memos left for monitoring rules can now be seen in alert notifications

Hello! Sales engineer id:Soudai here.

The weather has really started to warm up over the last week and I’m sure a lot of people will be out and about to see the cherry blossoms this weekend. I’m looking forward to taking a stroll myself and enjoying spring atmosphere.

Anyways, here is this week’s update information.

Memos left for monitoring rules can now be seen in alert notifications

We’ve expanded upon the recently released memo feature for monitoring rules. Memos are now also displayed in the alert details screen and notification channel when alerts occur. The channels that display monitor memos from alert notifications are as follows.

  • Slack
  • HipChat
  • ChatWork
  • Typetalk
  • OpsGenie
  • Reactio
  • Yammer

Whether identifying alert content or for maintenance purposes, alerts will become very clear. By all means, give it a try.

With the ability to write yourself a note on how to handle the next alert, possible causes, etc., this feature can be extremely useful.

Slack notifications

Alert details screen

mkr command v0.14.5 has been released

Color has been added to part of the output result when the Windows version mkr command is executed. This makes things a lot easier to understand when viewing the alerts list. For those of you who haven’t been using the mkr command, definitely give it a try.


The following have also been released

  • go-check-plugins v0.9.7 has been released
  • Parameter check fixed
  • mackerel-agent v0.41.3 has been released
  • Windows version stabilized

A joint Hands-On Seminar for 3 services

Mackerel, AWS, and Twilio will hold a joint hands-on seminar on Tuesday, April 25th. Definitely consider applying if you meet any of the following:

  • Infrastructure engineers and application engineers
  • Those who are interested in, but do not have experience in server monitoring or monitoring related work
  • Those who are interested in optimizing the server monitoring and notification systems of their company
  • Those who might have heard of “Mackerel”, but aren’t exactly sure what it is
  • Those who are interested in creating an automated system with AWS Lambda
  • Those interested in automatic calls with Twilio

For more information about this hands-on seminar, please check out the application site below. Sales engineer id:a-know will be presenting for Mackerel, so look forward to that!

We hope to see you there!