Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Update guide: "Easy profiling for Node.js" #449

Closed
wants to merge 1 commit into from
Closed

Update guide: "Easy profiling for Node.js" #449

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 5 additions & 10 deletions locale/en/docs/guides/simple-profiling.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,7 @@ code-creation,Stub,2,0x2d5000a33e00,507,"NumberToStringStub"
```

In the past you need the V8 source code to be able to interpret the ticks.
Luckily, tools have recently been introduced into Node.js 4.1.1 that facilitate
Luckily, tools have recently been introduced into Node.js 5.2.0 that facilitate
the consumption of this information without separately building V8 from source.
Let's see how the built-in profiler can help provide insight into application
performance.
Expand Down Expand Up @@ -134,15 +134,11 @@ passwords, or inside the Express framework itself.
Since we ran our application using the --prof option, a tick file was generated
in the same directory as your local run of the application. It should have the
form isolate-0x124353456789-v8.log. In order to make sense of this file, we need
to use the tick processor included in the Node.js source at
<nodejs_dir>/tools/v8-prof/tick-processor.js. It is important that the version
of the tick-processor that you run comes from the same version of node source as
version of node used to generate the isolate file. This will no longer be a
concern when the tick processor is [installed by default][]. The raw tick output
can be processed using this tool by running:
to use the tick processor which is bundled inside the Node.js binary. The raw tick
output can be processed using this tool by running:

```
node <path_to_nodejs_src>/tools/v8-prof/tick-processor.js isolate-0x101804c00-v8.log >processed.txt
node --prof-process isolate-0x101804c00-v8.log >processed.txt
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Nit: We probably want to find some way to generalize the file name. I wouldn't hold this up for that, though, if that is likely to be the source of much bike-shedding.

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Can we please keep the old command as well for users of 4.2 (LTS)?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Based on the discussion here, it seems likely that this change will land in LTS. My hope is to update the guide at that time to move the required version back from 5.2.0 to 4.2.x.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@Trott I thought the way you handled this generalization in #446 was good. I would be happy waiting for that one to land and then merging this change on top.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If someone wants to merge #446, great! If you'd rather just add that change into here yourself, that's great too!

```

Opening processed.txt in your favorite text editor will give you a few different
Expand Down Expand Up @@ -174,7 +170,7 @@ taking the most CPU time and see:
```

We see that the top 3 entries account for 72.1% of CPU time taken by the
program.From this output, we immediately see that at least 51.8% of CPU time is
program. From this output, we immediately see that at least 51.8% of CPU time is
taken up by a function called PBKDF2 which corresponds to our hash generation
from a user's password. However, it may not be immediately obvious how the lower
two entries factor into our application (or if it is we will pretend otherwise
Expand Down Expand Up @@ -282,5 +278,4 @@ example, you've seen how the V8 tick processor can help you gain a better
understanding of the performance of your Node.js applications.

[profiler inside V8]: https://developers.google.com/v8/profiler_example
[installed by default]: https://github.com/nodejs/node/pull/3032
[benefits of asynchronous programming]: https://nodesource.com/blog/why-asynchronous