1. Why a Wallboard
The wallboard is a status board screen that you leave up on a TV on the wall of a control room or an office. It uses the same data that OPENMARU APM collects, but it was built separately for conditions that differ from those of the console on your desk. This chapter explains why a separate screen was built, and so what the wallboard does and does not do.
A desk screen and a wall screen answer different questions
Even with the same APM data, the two screens answer different questions.
| APM console on the desk | Wallboard on the wall | |
|---|---|---|
| Who looks | One operator in charge | Many people moving around the office |
| Question | Why did it slow down, which request or which SQL is the cause | What is happening now, is everything fine |
| Viewing distance | 50 to 70 cm, within arm's reach | 3 to 10 m |
| Viewing time | Several minutes of close study | 1 to 2 seconds in passing |
| Interaction | Drill down to the cause with mouse and keyboard | None |
The console is a screen for drilling down to the cause, and the wallboard is a screen that tells you the current state. So if you put a console dashboard on a control room TV at a large size, neither job is done well. The small numbers and graphs of the console cannot be read from 3 m away, and the question the wallboard must answer, "is everything fine now", gets lost among dozens of widgets.
A wall screen has four conditions
It must be read from a distance
The console sets its font sizes and line widths for viewing at arm's length. A wall screen is viewed from 5 to 15 times farther away. Making the screen larger does not increase the amount of information a person can tell apart from a distance.
So each tile of the wallboard puts one large number and one moving visual in the center. The large number has a minimum font size: even when you split a 4K screen into 16 tiles, it does not go below 150 pixels (about 47 mm on a 55-inch 4K screen). A split that would make the text smaller than that cannot be selected at all (chapter 6). A screen with only server tiles is the exception: when tiles get small, they become mini tiles that show a one-line summary instead of the large number (chapter 7).
Nobody interacts with it
There is no mouse or keyboard in front of a wall screen. Descriptions that appear only when you hover the mouse (tooltips) and detail screens that you open by clicking cannot be used on a wall. The wallboard always puts a label next to each number, and writes any information that needs explaining as text on the screen.
Nobody refreshes it
A wall screen stays on all day, for weeks at a time. If the connection drops, nobody is there to press F5. On an unattended screen, the worst failure is not a screen that stops, but a screen that stops without anyone knowing. If the screen looks fine but the numbers are hours old, nobody thinks anything is wrong.
When the connection drops, the wallboard shows that on the screen and reconnects by itself (chapter 9).
Different viewers read different amounts
| Viewer | Time in front of the screen | What they read |
|---|---|---|
| An executive walking by | 1 to 2 seconds | Whether everything is fine: one signal |
| The operator at the monitoring desk | Most of the working day | 5 to 7 values such as delays, throughput, and error rate |
| Staff moving around | The corner of their eye | One color |
The wallboard divides these three layers across the screen. The large number in the center and its color give everyone the same signal, and the left and right sidebars and the summary below are information for an operator who comes closer (chapter 2).
What the wallboard does
- It tells you the current state with one large number and a color. In the application view this is the delayed transaction count; in the server view it is the worst usage among CPU, memory, and disk.
- It shows things getting worse at once, and things getting better slowly. A worsening appears on the screen immediately, and a recovery is shown only after a 6-second wait. This keeps the color from flickering near a threshold (chapter 4).
- It speaks through movement more than color. When things are normal the visual is quiet; the worse it gets, the faster and larger it becomes. What a person passing at a distance must notice is not "there is red" but "this is not how it usually looks" (chapter 5).
- It shows several workloads on one screen. It splits the screen into 1 to 16 tiles and shows a different group in each tile (chapter 6).
- It tells you what happened in one line at the bottom of the screen. It shows events created by alert policies in the alert band (chapter 8).
- It does not count a server that sends no values as normal. In the server view, a server that sends no values stays gray and is reported in a count (chapter 7). In the application view, if every WAS stops, no requests come in and the delayed count drops to 0. The number alone cannot tell this apart from normal, so check the agent stop events in the alert band and the LIVE indicator as well.
What the wallboard does not do
- Root cause analysis. Opening one slow request to see how it was processed is the job of the console's transaction trace. When you see a problem on the wallboard, check the cause in the console.
- Sending notifications. Notifying people by email or messenger is the job of the console's alert policies. The wallboard uses the same measure (the delayed count), but because it shows a worsening immediately, the red on the TV appears up to about 10 seconds before the alert email. "The TV is red but the email has not arrived yet" is normal.
- Sound. There is no way to know whether the TV has speakers, and there are no actions such as acknowledge or mute, so the wallboard makes no sound.
- Interaction on the screen. The wallboard is view-only. If you want to click through things right away, we recommend showing the console next to it.
How this guide is organized
| Part | Chapters | Read it when |
|---|---|---|
| Understanding | Chapters 1 to 2 | You want to know what the wallboard is and what the screen looks like |
| Getting Started | Chapter 3 | You put it on a TV for the first time |
| Task Guides | Chapters 4 to 9 | You read the numbers, choose the visual, split, server view, and alert band, and run it unattended |
| Reference | Chapters 10 to 11 | You look up a setting or an address value, or something goes wrong |
Copyright (c) 2026. OPENMARU, Inc.