H21. Building a Status Board with the TV Wallboard
Diátaxis: How-to · Audience: operators and administrators -- viewing needs no special permission, and the groups you can see follow your own permissions ← Back to contents
The TV wallboard puts the monitoring status on a TV or a large monitor for a room full of people to watch together. Where the console is a screen you go into and search, the wallboard is a screen read from three metres away, in passing. So it does not crowd the space with numbers -- it says the state with one large number and movement.
How to open it -- press the TV icon in the top header. It is visible on every screen.
- It opens in a new window (not a tab). If your browser blocks pop-ups, it opens in a new tab.
- It carries over the application group you are currently viewing in the console.
- To leave it up on an unattended TV, start the browser in kiosk mode (
--kioskor--app=<address>) so the screen is filled without an address bar.
Note The wallboard is dark only. It is a screen that stays up on a TV, and a bright background causes monitor burn-in. It stays dark regardless of the console's theme setting.
What Is on the Screen
One tile shows one application group.
| Area | What it is |
|---|---|
| Centre (the hero) | A large number and a moving figure -- this is the heart of the screen |
| Title | The application group being shown. Press it to switch to another group |
| Summary under the hero | One line, such as 11 of 48 in flight delayed |
| Left side panel | APDEX · active users · login users · error rate |
| Right side panel | Apdex distribution · TPS · average response time |
| Top bar | LIVE indicator · clock · full screen · settings (gear) |
As tiles get smaller (6 and 8 splits) the side panels fold away and only a one-line summary remains. The hero number and that summary survive to the end -- they are what has to be readable from three metres away.
Reading the Hero Number -- Look Here First
The large number in the centre is the count of delayed transactions. It shows the worst state within the group.
Its colour tells you the state.
| Colour | Meaning | Default threshold |
|---|---|---|
| Green | Normal | Below the warning threshold |
| Amber | Warning | 30 or more |
| Red | Critical | 50 or more |
Important These thresholds should differ per workload. If a service normally runs with 40 in the queue, the defaults leave the screen permanently amber, and then nobody notices when it actually gets worse. A warning that becomes the background is not a warning. Set it above that service's normal level.
The Three Colours Appear Twice -- and Mean Different Things
Green, amber, and red show up in two places, and they say different things. This is easy to mix up.
| Where | What it splits |
|---|---|
| The arc around the hero | Transaction state -- normal / delayed / pending |
| The "Apdex distribution" card in the right panel | How it felt to users -- satisfied / tolerating / frustrated |
The arc around the hero grows in proportion to the count while counts are small, and switches to proportion past a certain point. That way you never get "a full green bar at zero" -- when there is nothing, the arc is short.
The Apdex distribution card splits responses by how fast they felt to a person. If the delayed count is low but "frustrated" is high, the count is small but slow requests are mixed in.
The Six Hero Objects -- Which to Choose
Pick one of six. The numbers and the verdict are identical whichever you pick. The only difference is how the state is expressed as movement.
| Name | How it looks |
|---|---|
| Core Reactor | Particles orbit a central sphere and grow fierce as things worsen |
| Orbital Gate | Flow passing through a ring. When it jams the ring brightens and ripples spread |
| Pulse Field | Dots swell and shrink on a regular beat |
| Flood Field | A rising surface of water. As delays pile up the level climbs |
| Pulse Core | Particles flow inward from all sides. When they back up a band forms around the rim |
| Heartbeat | It beats like a heart, and motes scatter outward on the beat |
Read the Movement, Not the Colour
This is the most important reading habit on this screen.
The worse it gets, the faster, bigger, and less regular it becomes. Colour is only the final confirmation.
- Speed -- unhurried when healthy. As delays grow it visibly speeds up.
- Size and quantity -- the more that is backed up, the more particles and the larger the form.
- Regularity -- steady when calm. As it worsens it wobbles and jumps.
Why it was built this way If colour did all the talking, the screen would be just as busy when healthy, and trouble would not stand out. What a passer-by three metres away has to catch is not "there is red" but "this is not how it usually looks." So the healthy state was made deliberately quiet.
Splitting the Screen -- Several Groups at Once
Divide one screen into 1 / 2 / 3 / 4 / 6 / 8 tiles and put a different application group in each.
- Settings (gear) ▸ Layout ▸ Screen split, and choose the number of tiles.
- Press the title of each tile to choose the group it shows. Long lists can be searched.
- The gear on a tile changes the hero for that tile alone.
Your choices are saved per tile and restored the next time you open it.
Note The split cannot be chosen, or is reduced automatically, in these cases.
- The tiles would be too small for the screen -- it tells you so. A size that cannot be read from three metres away is never produced.
- There are not enough application groups -- it splits only as far as the groups you have.
Even when it is reduced automatically, your choice is not erased. Open it again on a large TV and it returns to the number of tiles you picked.
Specifying It by URL
When an unattended TV has to come up on a fixed layout, put the conditions in the address.
| Parameter | Meaning |
|---|---|
?split=N | Number of tiles |
?group=<name> | The group to show when there is one tile |
?groups=<g1,g2,…> | Group per tile (comma separated) |
?hero=<name> · ?heroes=<n1,n2,…> | Hero selection |
Settings
Pressing the gear opens the settings, in three sets.
| Set | Items |
|---|---|
| Layout | Screen split · side panels (Overview / Details / None) · sidebar position · Centre view (choosing the hero) |
| Alert thresholds | Warning at · Critical at -- adjusted in steps of 10 |
| Appearance | Chart colour · transaction balls (show, size, colour) · login users |
- Thresholds move in steps of 10 only. This is the verdict line for a screen read from three metres away, so single-unit precision means nothing, and two buttons are enough to adjust it standing in front of an unattended TV.
- Transaction balls (the animation of requests flying) turn off automatically at 6 and 8 splits -- once tiles are that small the balls cannot be seen anyway and only cost drawing time.
- Reset to defaults restores everything except Layout. Losing the split and group arrangement you set up would be more trouble than help.
When the Connection Drops
The wallboard stays up for a long time, so it does not hide a dropped connection.
- On a drop it keeps the last screen and merely stops updating. The screen does not blank or fall to zero -- that would read as an outage.
- The LIVE indicator at the top changes, and pressing it reconnects.
- If your login expires, a bar appears with a Refresh button to bring it back.
Note A display that has stopped is not the same as a value that is genuinely zero. Check the LIVE indicator first.
Language and Names
- It follows the display language (Korean or English) chosen in the console.
- If you have set display names (aliases)
on groups or instances, the wallboard shows those names too. On a screen a room watches together,
a business name reads far better than
prod-order-was-01.
When It Does Not Work
| Symptom | What to check |
|---|---|
| Pressing the TV button opens nothing | Check the browser's pop-up blocker -- when blocked it opens in a new tab |
| The split you want cannot be chosen | Either the screen is too small for tiles that size, or there are not enough application groups |
| The screen looks frozen | Check the LIVE indicator at the top and press it to reconnect. If a login-expired bar is showing, press Refresh |
| The number is always amber or red | The thresholds sit below that service's normal delay count -- raise them under Settings ▸ Alert thresholds |
| A group is missing from the list | Whether your account has permission for that group → H18 |
| Text is small on a large screen | Reduce the number of tiles. The larger the tile, the larger the text |
| Transaction balls are not visible | They turn off automatically at 6 and 8 splits. Check the state under Settings ▸ Appearance |
Related Documents
- H19. Bundling Targets into Application Groups -- creating groups and display names
- H18. Managing Users, Groups, and Permissions -- the scope of groups you can see
- R4. Common UI Elements -- where the TV button sits in the top bar
- T2. Tracing a Slow Request -- digging into the console after spotting something on the wallboard