FacebookAds\Exception\Exception, Code: 35: LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to graph.facebook.com:443

Question

Seemingly out of the blue (i.e. I haven't edited code recently), I've started receiving a lot of these error messages in my cron jobs in the past couple days:

FacebookAds\Exception\Exception, Code: 35: LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to graph.facebook.com:443

As a test, I was able to SSH into my server and run this without problem: curl -vvv https://www.facebook.com

Also, the cron job that runs every 5 minutes and often causes this error doesn't always cause this error. And in the few times I've manually dispatched the job, I haven't seen the error.

What does this mean, what suddenly caused my cron job to often throw this error, and how can I fix it?

_{P.S. These seem to be related questions but none seem to have answers about LibreSSL and Facebook:}

• _{Laravel 5.7 OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to graph.facebook.com:443}
• _{Facebook PHP SDK: Unknown SSL protocol error}
• _{SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443}
• _{fatal: unable to access 'https://github.com/xxx': LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443}

Answer 1

I still don't know the root cause, but I ran service docker restart and haven't noticed the error since.

Thanks to https://stackoverflow.com/a/52740968/470749 for the idea.

Answer 2

Had a similar error message while installing ruby gems. Upgrading the OS to Mojave 10.14.5, solved the problem for me.