# Viewing microbenchmarks with Chromeperf

[TOC]

## Overview

Chromeperf is a system for monitoring and visualizing benchmark results.
It is maintained by the Chrome team.  This guide describes how to find and
use the results of your benchmarks in Chromeperf.

Chromeperf is sometimes referred to as the "Catapult performance dashboard"
in the Fuchsia codebase, or just "Catapult" for short, because its code
lives in the [Catapult project Git repo][catapult-repo].

[catapult-repo]: <https://chromium.googlesource.com/catapult/>


## Accessing the dashboard

The dashboard can be found at
[https://chromeperf.appspot.com/report](https://chromeperf.appspot.com/report).

**Note that Fuchsia data is currently only available to Googlers.**  You
will need to sign in with a google.com account for the Fuchsia performance
results to be visible in Chromeperf.  Click **Sign in** in the top right
corner to do that.


## Searching and adding graphs

The dashboard displays a list of search boxes.  The placeholder names are relics from the
days when Chrome infrastructure was still using BuildBot.  Since they are not relevant to
Fuchsia infrastructure, Fuchsia data is mapped to these fields with the following scheme:

* `Test suite` == the name of the benchmark suite.
* `Bot` == A Fuchsia LUCI builder that has run the benchmark at least once.
* `Subtest` == The name of the test case in your benchmark suite.

Type the name of your benchmark suite in the first box to begin searching.  For
example, if there is a benchmark suite named "zircon_benchmarks", it will get
displayed with autocomplete if you type "zircon".

![test_suite_example](/docs/images/benchmarking/test_suite_example.png "test_suite_example")

Select a builder and a subtest.  Note that if your subtest is named "foo", there will be
multiple "foo_<metric_name>" subtests to choose from.  Each of these represents a metric
computed from the sample(s) of that subtest.  For example: if "foo" generates N sample
points each time the benchmark is run, then the subtest "foo_avg" is a plot of the
averages of these N samples.

When you're finished filling out each field, click **Add** to add your graph to the UI.
You should see something like this:

![graph_example](/docs/images/benchmarking/graph_example.png "graph_example")


## Viewing sample metadata

If you hover over a point in a graph, you can see some extra information such as the
point's value, the date it was recorded, and a link to the log page of the build that
generated it.

![tooltip_example](/docs/images/benchmarking/tooltip_example.png "tooltip_example")


## Saving the view

Chromeperf's web UI does not have a built-in mechanism for saving a collection
of graphs.  If you want to save a list of graphs so that you can share with others or
re-open the list later, you can copy the URL from the Chrome Address Bar.

Beware, you will have to re-copy the URL each time you add, modify or remove a graph. This
includes moving the green slider beneath a graph or making any selections in the box to
the right of the graph.