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Comment by mabbo | Hacker News Reader

> EFS file systems now provide average latency as low as 600 microseconds for the majority of read operations on data and metadata.

I do not want to detract from how awesome this is at all. It's a great improvement and worth of celebration.

That said, I spent long enough at Amazon to know that they have the metrics around this, before and after, to a surprising level of detail. When Amazon gives a single piece of data like that, it makes me worry me there is some nuance to the improvement. Show me the p50, p90, p99, and p99.99 as well as the average.

Remember, if reading 1 byte is improved 10X on average, but one in every 10,000 bytes is worsened by 10X, then 10kb file reads might now take ~10X longer (if all reads were in parallel, etc).

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(PMT on the EFS team).

Yes, the wordings are carefully formulated as they have to be signed off by the AWS legal team for obvious reasons. With that said, this update was driven by profiling real applications and addressing the most common operations, so the benefits are real. For example, a simple WordPress "hello world" is now about 2x as fast as before.

> For example, a simple WordPress "hello world" is now about 2x as fast as before.

Before seeing this announcement, someone at work today literally said "the wordpress site is feeling very fast today, I wonder if anything has changed?" Great work!

If you don't mind me asking, why do you run Wordpress off of EFS rather than EBS?

EFS allows you to connect to the filesystem from multiple web front-end machines. Doing the same with EBS would require you to manage some sort of clustered filesystem, or run a separate storage tier server.

So you are using it for shared files and user-generated files, not database? Instead of S3?

Wordpress Plugins are stored both in the filesystem and in the database and need to match. Same for the Wordpress Core when an update occurs as WP updates the PHP files locally for the upgrade process. The AWS guidance for a multi-webserver Wordpress setup has included EFS for this reason for years now. You can store uploaded media in S3, but that is a performance optimization that doesn't solve the previous issues.

So you mean the plugins' code, I see, thanks!

Not OP but the obvious use case for Wordpress is the install directory itself. Deploy to one server and have all servers sharing the EFS get the update at the same time.

So PHP rereads the source files on every request? Interesting.

There's a cache. Even if you have to restart some process or purge some cache, this setup makes sense to me for applications that can update their own code (e.g. install/update plugins).

Current SLA is only on uptime: https://aws.amazon.com/efs/sla/

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