EAGAIN / EWOULDBLOCK Error

[stamhankar999]

A user running v2.1.5 of the DataStax Ruby driver encountered a 'write would block' error message when communicating with a node. We believe the underlying error is an EAGAIN or EWOULDBLOCK when attempting to write to the socket.

Looking at the ione code (v1.2.0 for C* driver 2.1.5), I don't see how we could end up with that error -- writes seem rely strictly on select returning a write-fd-set, so if the fd isn't writable, it shouldn't get a write attempt.

Nonetheless, it seems like in some cases it does get this error, so ione should catch it and drop it. Presumably a later write attempt will succeed as time elapses and the kernel buffer for the socket gradually empties.

[iconara]

I would need more info to go ahead with this. As you say it's hard to see how it could happen, and just rescuing exceptions without knowing the cause of them will probably lead to more errors, or hidden performance issues, in the future.

[stamhankar999]

Sounds reasonable; I'm trying to find out if the user can repro the issue. Will let you know more when I know more.

[iconara]

Thanks.