A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds. This optimization process with so much fun, and so many people pitched in with their ideas; so I eventually decided I wanted to do something more.
That's why I built a performance challenge for the PHP community
The goal of this challenge is to parse 100 million rows of data with PHP, as efficiently as possible. The challenge will run for about two weeks, and at the end there are some prizes for the best entries (amongst the prize is the very sought-after PhpStorm Elephpant, of which we only have a handful left).
A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds.
When people say leetcode interviews are pointless I might share a link to this post. If that sort of optimization is possible there is a structures and algorithms problem in the background somewhere.
Microbenchmarks are very different from optimizing performance in real applications in wide use though, they could do great on this specific benchmark but still have no clue about how to actually make something large like Wordpress to perform OK out of the box.
> A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds
That's a huge improvement! How much was low hanging fruit unrelated to the PHP interpreter itself, out of curiosity? (E.g. parallelism, faster SQL queries etc)
- Cursor based pagination
- Combining insert statements
- Using database transactions to prevent fsync calls
- Moving calculations from the database to PHP
- Avoiding serialization where possible
in all my years doing database tuning/admin/reliability/etc, performance have overwhelmingly been in the bad query/bad data pattern categories. the data platform is rarely the issue
In general, it is bad practice to touch transaction datasets in php script space. Like all foot-guns it leads to Read-modify-write bugs eventually.
Depending on the SQL engine, there are many PHP Cursor optimizations that save moving around large chunks of data.
Clean cached PHP can be fast for REST transactional data parsing, but it is also often used as a bodge language by amateurs. PHP is not slow by default or meant to run persistently (low memory use is nice), but it still gets a lot of justified criticism.
Erlang and Elixir are much better for clients/host budgets, but less intuitive than PHP =3
PHP has always escaped forward slashes to help prevent malicious JSON from injecting tags into JavaScript I believe. Because it was common for PHP users to json_encode some data and then to write it out into the HTML in a script tag. A malicious actor could include a closing script tag, and then could inject their own HTML tags and scripts etc.
> The output should be encoded as a pretty JSON string.
So apparently that is what they consider "pretty JSON". I really don't want to see what they would consider "ugly JSON".
(I think the term they may have been looking for is "pretty-printed JSON" which implies something about the formatting rather than being a completely subjective term)
This is why I jumped from PHP to Go, then why I jumped from Go to Rust.
Go is the most battery-included language I've ever used. Instant compile times means I can run tests bound to ctrl/cmd+s every time I save the file. It's more performant (way less memory, similar CPU time) than C# or Java (and certainly all the scripting languages) and contains a massive stdlib for anything you could want to do. It's what scripting languages should have been. Anyone can read it just like Python.
Rust takes the last 20% I couldn't get in a GC language and removes it. Sure, it's syntax doesn't make sense to an outsider and you end up with 3rd party packages for a lot of things, but can't beat it's performance and safety. Removes a whole lot of tests as those situations just aren't possible.
If Rust scares you use Go. If Go scares you use Rust.
I am not that smart to use Rust so take it with a grain of salt. However, its syntax just makes me go crazy. Go/Golang on the other hand is a breath of fresh air. I think unless you really need that additional 20% improvement that Rust provides, Go should be the default for most projects between the 2.
I hear you, advanced generics (for complex unions and such) with TypeScript and Rust are honestly unreadable. It's code you spend a day getting right and then no one touches it.
I'm just glad modern languages stopped throwing and catching exceptions at random levels in their call chain. PHP, JavaScript and Java can (not always) have unreadable error handling paths not to mention hardly augmenting the error with any useful information and you're left relying on the stack trace to try to piece together what happened.
Sorry, but it's honestly just a lot of our journeys. Started on scripting languages like PHP/Ruby/Lua (self-taught) or Java/VB/C#/Python (collage) and then slowly expanded to other languages as we realized we were being held back by our own tools. Each new language/relationship makes you kick yourself for putting up with things so long.
I understand that but there's a time and a place. Rust has nothing to do with this. 100% of the people on this site understand that this challenge can be done faster in C, or Rust, or whatever. This is a PHP challenge. Perhaps we could discuss the actual submission as opposed to immediately derailing it.
It sounds plausible, but they really need to spell out exactly what the formatting requirements are, because it can make a huge difference in how efficiently you can write the json out.
A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds. This optimization process with so much fun, and so many people pitched in with their ideas; so I eventually decided I wanted to do something more.
That's why I built a performance challenge for the PHP community
The goal of this challenge is to parse 100 million rows of data with PHP, as efficiently as possible. The challenge will run for about two weeks, and at the end there are some prizes for the best entries (amongst the prize is the very sought-after PhpStorm Elephpant, of which we only have a handful left).
I hope people will have fun with it :)
A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds.
When people say leetcode interviews are pointless I might share a link to this post. If that sort of optimization is possible there is a structures and algorithms problem in the background somewhere.
Pitch this to whoever is in charge of performance at Wordpress.
A Wordpress instance will happily take over 20 seconds to fully load if you disable cache.
Microbenchmarks are very different from optimizing performance in real applications in wide use though, they could do great on this specific benchmark but still have no clue about how to actually make something large like Wordpress to perform OK out of the box.
That's often a skill issue.
> A month ago, I went on a performance quest trying to optimize a PHP script that took 5 days to run. Together with the help of many talented developers, I eventually got it to run in under 30 seconds
That's a huge improvement! How much was low hanging fruit unrelated to the PHP interpreter itself, out of curiosity? (E.g. parallelism, faster SQL queries etc)
Almost all, actually. I wrote about it here: https://stitcher.io/blog/11-million-rows-in-seconds
A couple of things I did:
- Cursor based pagination - Combining insert statements - Using database transactions to prevent fsync calls - Moving calculations from the database to PHP - Avoiding serialization where possible
Aren’t these optimizations less about PHP, and more about optimizing how your using the database.
It's still valid as as example to the language community of how to apply these optimizations.
in all my years doing database tuning/admin/reliability/etc, performance have overwhelmingly been in the bad query/bad data pattern categories. the data platform is rarely the issue
The worst offenders I've seen were looping over a shitty ORM
In general, it is bad practice to touch transaction datasets in php script space. Like all foot-guns it leads to Read-modify-write bugs eventually.
Depending on the SQL engine, there are many PHP Cursor optimizations that save moving around large chunks of data.
Clean cached PHP can be fast for REST transactional data parsing, but it is also often used as a bodge language by amateurs. PHP is not slow by default or meant to run persistently (low memory use is nice), but it still gets a lot of justified criticism.
Erlang and Elixir are much better for clients/host budgets, but less intuitive than PHP =3
exec(‘c program that does the parsing’);
Where do I get my prize? ;)
The FAQ states that solutions like FFI are not allowed because the goal is to solve it with PHP :)
What about using the filesystem as an optimized dict implementation?
this is never going to be faster because it requires syscalls
The time you lose at the syscall boundary you may be able to win back during much shorter GC pauses.
Are they just confused about what characters require escaping in JSON strings or is PHP weirder than I remember?
PHP has always escaped forward slashes to help prevent malicious JSON from injecting tags into JavaScript I believe. Because it was common for PHP users to json_encode some data and then to write it out into the HTML in a script tag. A malicious actor could include a closing script tag, and then could inject their own HTML tags and scripts etc.
That's the default output when using json_encode with the JSON_PRETTY_PRINT flag in php.
> The output should be encoded as a pretty JSON string.
So apparently that is what they consider "pretty JSON". I really don't want to see what they would consider "ugly JSON".
(I think the term they may have been looking for is "pretty-printed JSON" which implies something about the formatting rather than being a completely subjective term)
Side note - I wasn't aware that there is active collectors scene for Elephpants, awesome!
https://elephpant.me/
Elephpants should be for second and third place. First place should be the double-clawed hammer.
Excellent project. My favorites: the joker, php storm, phplashy, Molly.
I love Mollie!
This is why I jumped from PHP to Go, then why I jumped from Go to Rust.
Go is the most battery-included language I've ever used. Instant compile times means I can run tests bound to ctrl/cmd+s every time I save the file. It's more performant (way less memory, similar CPU time) than C# or Java (and certainly all the scripting languages) and contains a massive stdlib for anything you could want to do. It's what scripting languages should have been. Anyone can read it just like Python.
Rust takes the last 20% I couldn't get in a GC language and removes it. Sure, it's syntax doesn't make sense to an outsider and you end up with 3rd party packages for a lot of things, but can't beat it's performance and safety. Removes a whole lot of tests as those situations just aren't possible.
If Rust scares you use Go. If Go scares you use Rust.
I am not that smart to use Rust so take it with a grain of salt. However, its syntax just makes me go crazy. Go/Golang on the other hand is a breath of fresh air. I think unless you really need that additional 20% improvement that Rust provides, Go should be the default for most projects between the 2.
I hear you, advanced generics (for complex unions and such) with TypeScript and Rust are honestly unreadable. It's code you spend a day getting right and then no one touches it.
I'm just glad modern languages stopped throwing and catching exceptions at random levels in their call chain. PHP, JavaScript and Java can (not always) have unreadable error handling paths not to mention hardly augmenting the error with any useful information and you're left relying on the stack trace to try to piece together what happened.
It's almost comical how often bring up Rust. "Here's a fun PHP challange!" "Let's talk about Rust..."
Sorry, but it's honestly just a lot of our journeys. Started on scripting languages like PHP/Ruby/Lua (self-taught) or Java/VB/C#/Python (collage) and then slowly expanded to other languages as we realized we were being held back by our own tools. Each new language/relationship makes you kick yourself for putting up with things so long.
I understand that but there's a time and a place. Rust has nothing to do with this. 100% of the people on this site understand that this challenge can be done faster in C, or Rust, or whatever. This is a PHP challenge. Perhaps we could discuss the actual submission as opposed to immediately derailing it.
> Also, the generator will use a seeded randomizer so that, for local development, you work on the same dataset as others
Except that the generator script generates dates relative to time() ?
How large is a sample 100M row file in bytes? (I tried to run the generator locally but my php is not bleeding-edge enough)
Around 7GB
> The output should be encoded as a pretty JSON string.
...
> Your parser should store the following output in $outputPath as a JSON file:
They don't define what exactly "pretty" means, but superflous escapes are not very pretty in my opinion.They probably mean "Should look like the output of json_encode($data, JSON_PRETTY_PRINT)". Which most PHP devs would be familiar with.
It sounds plausible, but they really need to spell out exactly what the formatting requirements are, because it can make a huge difference in how efficiently you can write the json out.
Awesome. I’ll be following this. I’ll probably learn a ton.