> ## Documentation Index
> Fetch the complete documentation index at: https://docs.soldexer.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Profiling

> Measure where time is spent in a Solana pipe

Pipes SDK ships a built-in per-batch profiler. It records how long each part of the pipeline takes. When a [`metricsServer()`](../../reference/utility-components/metrics-server) is attached to the source, the profiler output is served as JSON at `http://localhost:<metrics_port>/profiler` and rendered live in [Pipes UI](../basic-development/pipes-ui).

## Enabling the profiler

The profiler is **on by default** when `process.env.NODE_ENV !== 'production'` and **off** otherwise. Override explicitly with `profiler: true` or `profiler: false` on the source.

```ts theme={null}
solanaPortalStream({
  portal: 'https://portal.sqd.dev/datasets/solana-mainnet',
  outputs: /* ... */,
  metrics: metricsServer({ port: 9090 }),
  profiler: true,   // force on — useful in production
})
```

## Interpreting the output

The pipeline is represented as a tree. Each node reports how long was spent in that stage of a batch. A typical tree looks like:

```
batch
├── fetch data
├── apply transformers
│   ├── track progress
│   └── Solana decoder
├── clickhouse
│   ├── data handler
│   ├── insert cursor
│   └── cleanup cursors
└── metrics processing
```

## Custom spans

Wrap any code in your target or transformer to get it to appear as a tree node. `ctx.profiler.start()` is a no-op when the profiler is disabled, so the instrumentation is safe to leave in place.

```ts theme={null}
onData: async ({ data, ctx }) => {
  const span = ctx.profiler.start('my measure')
  await myDataProcessing(data)
  span.end()
},
```

The named span appears under its parent node in the tree:

```
batch
...
├── clickhouse
│   ├── data handler
│   │   └── my measure
...
```