arniesmtpbufferserver VS kubeblocks

My guess is that many people are implementing queuing mechanisms just for sending email.

The Linux file system makes a perfectly good basis for a message queue since file moves are atomic.

You can see how this works in Arnie SMTP buffer server, a super simple queue just for emails, no database at all, just the file system.

https://github.com/bootrino/arniesmtpbufferserver

A practical applications of atomic mv is building simple file based queuing mechanisms.

For example I wrote this SMTP buffer server which moves things to different directories as a simple form of message queue.

https://github.com/bootrino/arniesmtpbufferserver

Caveat I think this needs examination from the perspective of fsync - i.e. I suspect the code should be fsyncing at certain points but not sure.

I actually wrote (in Rust) a simple file based message queue using atomic mv. It instantly maxed out the SSD performance at about 30,000 messages/second.

Yeah I was using Celery for sending emails - nothing else.

And it was such a nightmare to configure and debug and such overkill for email buffering that in a fit of frustration I wrote the Arnie SMTP buffering server and ditched Celery.

https://github.com/bootrino/arniesmtpbufferserver

It's only 100 lines of code:

https://github.com/bootrino/arniesmtpbufferserver/blob/maste...

Here's the 100 lines of code:

https://github.com/bootrino/arniesmtpbufferserver/blob/master/arniesmtpbufferserver.py

Here's the github repo:

https://github.com/bootrino/arniesmtpbufferserver

It's MIT licensed.

Arnie is a server that has the single purpose of buffering outbound SMTP emails.

A typical web SAAS needs to send emails such as signup/signin/forgot password etc.

The web page code itself should not directly write this to an SMTP server. Instead they should be decoupled. There's a few reasons for this. One is, if there is an error in sending the email, then the whole thing simply falls over if that send was executed by the web page code - there's no chance to resend because the web request has completed. Also, execution of an SMTP request by a web page slows the response time down of that page, whilst the code goes through the process of connecting to the server and sending the email. So when you send SMTP email from your web application, the most performant and safest way to do it is to buffer them for sending. The buffering server will then queue them and send them and handle things like retries if the target SMTP server is down or throttled.

There's a few ways to solve this problem - you can set up a local email server and configure it for relaying. Or in the Python world people often use Celery. Complexity is the down side of using either Celery or an email server configured for relaying - both of these solutions have many more features than needed and can be complex to configure/run/troubleshoot.

Arnie is intended for small scale usage - for example a typical web server for a simple SAAS application. Large scale email traffic would require parallel sends to the SMTP server.

Arnie sequentially sends emails - it does not attempt to send email to the SMTP server in parallel. It probably could do fairly easily by spawning email send tasks, but SMTP parallelisation was not the goal in writing Arnie.

https://github.com/apecloud/kubeblocks/blob/main/docs/releas...

Depending on one's needs and interests, they changed it from Apache 2 a few months ago: https://github.com/apecloud/kubeblocks/blob/5ba9b39716940cd7... I didn't dig into the changes to see if there's anything super interesting that happened between then and now

It really, really jams me up that the GitHub license thing is so stupid that when looking at a file containing the Apache 2 license it continues to say AGPL right across the top of that file. It's so misleading. Their license sniffer always shows $default_branch/LICENSE regardless of what branch (or file) one is looking at