Easy way to handle disconnections?

[sardaukar]

When I use curl to poll events, all goes well but as soon as I exit curl I get:

GET /reload_events/ - Unhandled exception:
Error writing to socket: Broken pipe (IO::Error)
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/socket.cr:82:13 in 'unbuffered_write'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/io/buffered.cr:218:5 in 'flush'
  from lib/sse/src/sse/server_sent_events_handler.cr:32:9 in 'sink'
  from lib/sse/src/sse/server_sent_events_handler.cr:37:53 in 'run'
  from lib/sse/src/sse/server_sent_events_handler.cr:54:11 in 'call'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server/handler.cr:28:7 in 'call_next'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server/handlers/compress_handler.cr:12:5 in 'call'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server/handler.cr:28:7 in 'call_next'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server/handlers/log_handler.cr:11:30 in 'call'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server/handler.cr:28:7 in 'call_next'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server/handlers/error_handler.cr:15:7 in 'call'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server/request_processor.cr:48:11 in 'process'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server/request_processor.cr:22:3 in 'process'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server.cr:498:5 in 'handle_client'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/http/server.cr:464:13 in '->'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/fiber.cr:255:3 in 'run'
  from /home/sardaukar/.asdf/installs/crystal/0.34.0/share/crystal/src/fiber.cr:92:34 in '->'
  from ???

Is there a best-practice on catching disconnections? Thanks!

[y2k2mt]

Thank you for reporting!
This problem does not seem to be reproducible in my environment.
Can you show me the implementation of HTTP::ServerSentEvents::Handler?

[sardaukar]

This seems to be a problem with how Crystal handles EPIPE. I've opened an issue because I gave up on SSE and moved to WebSockets but it keeps happening crystal-lang/crystal#9135

Interesting that it doesn't happen for you... are you on Linux or Mac?

[y2k2mt]

Thank you for sharing. I will subscribe to them.

Interesting that it doesn't happen for you... are you on Linux or Mac?

I've tested it on Debian and Mac, and both environments finish a process without any output.
It seems to ignore an error on disconnection.

crystal-lang/crystal#9065 (comment)

[rdp]

How to repro the issue, exacly?

[sardaukar]

I have a repo up to help reproduce it https://github.com/sardaukar/websocket_issue but I've worked around it now. Thanks anyway