# The Inspector

> The panel that opens when you select a Node. Its warnings, Resources gauges, Instance sizes, Calls (Link settings and policies), and Upgrade all.

Click a Node and the Inspector opens on the right. It is where you read why a Node is slow and where you change its size, its options and the policy of each Link it sends.

![The Inspector open on an App Server: header, warning box, Resources and Instance.](https://wiki.playquorum.dev/play/inspector.png)

Look at the red box under the title and the **Resources** gauges below it. They answer why the card is full.

Close it with the **Close** button (the X) or `Esc`. Select another Node and it shows that one. Arrow keys select the nearest Node, and `Enter` on a selected Node moves focus into the panel.

## Top to bottom

1. **Header.** The Component's icon, its name and ordinal, the product it stands for, and a size badge.
2. **Blurb.** One line on what the Component does.
3. **Warnings.** A red or amber box for a problem right now. Examples: **Out of RAM and swapping: every request is slower.** (red), **Out of CPU credits: throttled to 20% CPU.** (amber), **Refusing 12/s queries: too many connections.** (red). A box can carry a button, such as **Restart** under a memory leak.
4. **Live now.** The Node's current figures, such as requests per second and latency. With Analytics linked, a traffic breakdown follows. With the `metrics` Research, **Load, last day** draws a trend line.
5. **Resources.**
6. **Instance.**
7. Sections for the Component's own options. Which ones appear depends on the Component, such as the **Stack** of an App Server or the policy of a Load Balancer.
8. **Calls.**
9. **Upgrade all**, then the footer buttons.

## Resources

The first bar is the goal bar, named **Limit · CPU** or the resource that caps the Node now. Below it, one gauge per resource the Node has:

- **CPU**: cores used out of cores owned.
- **RAM**: GB used out of GB owned.
- **Workers busy**: slots in use out of slots total.
- **Connections**: open connections out of the maximum.
- **CPU credits**: the balance of a Burstable box. This bar reads the room left, so a nearly empty bar is the trouble.
- **Network**: traffic out of the network card.

When a limit has no gauge, the goal bar says so, for example **Disk IOPS · no gauge**. **Nothing tight** in green means no limit is close.

Read it like this: the warning box names the symptom, the goal bar names the limit, and the gauge shows how far along it is.

## Instance

**Instance** appears for sized Components, such as App Servers and Databases. It shows the size name with its vCPU and RAM.

- **Smaller (free)** drops one size and costs nothing, but the Node restarts and the Cash you paid for the size does not come back.
- **Larger · $** buys one size. A click buys one. Hold it to buy more, one every quarter of a second. The key `U` does the same for the selected Node.
- **Buy ten sizes** and **Buy to the largest size** buy several in a row, as far as your Cash goes. A toast says what happened and ends with **Undo (Z) refunds $x for 30 s.**
- The family row picks **Burstable**, **General**, **Compute**, **Memory** or **ARM**. A family can show a Tradeoff card first. Read it and press **Confirm**.

Refusals are plain: **App Server is at its largest size.** and **App Server is at its smallest size.**

## Calls

**Calls** lists every Link that leaves this Node, one block per target. It appears after the **Timeouts and retries** Research. The Link itself has no settings panel, so you edit its policy from the Node that sends the call.

Each block starts with the target's name. The rows below are pickers. Pick one option in each row.

| Row | Options | How to read it |
| --- | --- | --- |
| Timeout | **1 s**, **5 s**, **30 s** | How long the caller waits. A short timeout frees the caller's slot sooner, but it fails calls that would have worked. 30 s is the default. |
| Retries | **No retries**, **Retry 3×**, **Backoff** | **Retry 3×** retries at once, up to three times, which multiplies load on a callee that is already failing. **Backoff** waits between retries and adds at most a tenth more calls. **Backoff** needs the Backoff with jitter Research. |
| Breaker | **No breaker**, **Breaker** | A **Breaker** stops the calls for 5 s when half of them fail. The label reads **Breaker open** while it is open. Needs Circuit breakers. |
| Bulkhead | **No bulkhead**, **Bulkhead** | A **Bulkhead** gives up on a call after 1 s and frees the slot. Needs Bulkheads. |
| Hedge | **One copy**, **Hedge** | **Hedge** sends a second copy of a slow call and keeps the faster answer. The tail drops, and the callee sees more calls. Needs Hedged requests. |

A row that its Research has not unlocked is missing, or its option is off. If you force an action that is locked, the toast names the Research, for example **Backoff needs Backoff with jitter.**

A Load Balancer adds a policy section of its own, with the request kinds each Link carries.

Pick **Backoff** plus **Breaker** on the Link into a Database to stop a retry storm. [Stop a retry storm](https://wiki.playquorum.dev/guides/stop-a-retry-storm.md) walks through the case.

## Upgrade all

**Upgrade all N** shows when the Board has two or more Nodes of the same Component in this region. One press grows every one of them by one size. N counts the Nodes that can still grow. A toast reads, for example, **App Server ×3 grew one size.** and adds **Cash ran out.** when Cash ended the run. The button is off when nothing can grow or you cannot pay.

## The footer

- **Collect** on Payments, with the amount in the drawer.
- The size button, which reads **Bigger drawer** on Payments, **More samples** on Analytics, and a size name elsewhere. Unlike the card footer, a click buys here.
- **Restart** on App Servers and Workers. It frees leaked memory, and the Node comes back cold.
- **Drain** after the Health checks Research. It stops new traffic and lets the Node finish what it holds.
- **Sell**, whose tooltip reads **Sell for $x (Delete)**. It opens the confirm bar. Fixed Nodes have no **Sell**.

## Mistakes to avoid

- Hunting for settings by clicking a Link. Select the Node at the sending end and open **Calls**.
- Buying **Larger** when the goal bar names **Connections** or **Workers busy**. More CPU does not fix a connection cap.
- Choosing **Retry 3×** on a Link to a struggling Database.
- Leaving a Burstable box when **CPU credits** reaches zero. Change the family, or the box stays throttled.

Next: [Clock, undo, saves](https://wiki.playquorum.dev/play/clock-undo-saves.md).

Source: https://wiki.playquorum.dev/play/the-inspector