SSE Watcher issues #1744
Comments
|
Also perhaps relevant, the Mozilla docs on SSE contain this warning. I don't think Crystal has any packaged HTTP2 support yet.
|
robacarp
changed the title
|
As well, I've just come across this. It appears that, since even after disconnect the loop still spins, when a reload event is triggered every open connection which is no longer tied to the browser throws an exception. After the exception is thrown, the loop is obviously terminated. Which (accidentally) mitigates this bug at least a bit.
|
|
I witnessed this behavior just now. If I boot the server, and then trigger a recompile before loading a page with the browser, the first time I do the page is immediately reloaded. |
|
Ah ok, I guess my implementation was a little naive when I thought just changing I was already aware of the limitations of SSE, but I know some people swear by it, so I thought it was worth keeping around. I think my new implementation would be to store each request Context in a list, that when a reload should happen, it just pops each one off and runs the reload logic, then only break the loop when the context is closed. We'll see if that works. |
|
@robacarp would you be willing to try out some of my fixes with your local setup? |
Describe the bug
This could pretty easily fall into the simple territory of a bug we're okay living with.
In development mode, with
lucky watch --watcher=sse, each time a browser is connected to the SSE server, a new loop is initiated withsleep 0.1s.Simply clicking around on a site, navigating around pages, it's easy to get this loop spinning dozens of times.
I think this would cause an issue if the lucy dev server is running for a long time, and active development is refreshing the page over and over.
To Reproduce
Steps to reproduce the behavior:
Screenshots/code
I was able to prove that this happens by modifying lib/lucky/tasks/watch.cr like this. After modifying the file,
rm bin/lucky.watchand thenlucky devwill compile the task on and run it.def initialize @server = HTTP::Server.new do |context| context.response.headers.merge!({ "Access-Control-Allow-Origin" => "*", "Content-Type" => "text/event-stream", "Connection" => "keep-alive", "Cache-Control" => "no-cache", }) context.response.status_code = 200 + puts "SSE Activated".colorize(:green) + n = rand(1000000) # SSE start loop do + puts "SSE Loop #{n}" if @should_restart + puts "Triggering SSE reload" context.response.print "data: update\n\n" context.response.flush @should_restart = false break end sleep 0.1 end + puts "SSE Deactivated".colorize(:red) # SSE stop end endVery Verbose Output:
Versions (please complete the following information):
The text was updated successfully, but these errors were encountered: