redis cluster continuously print log WSA_IO_PENDING

There is no way to specifically turn those "warnings" off in 3.2.x port of Redis for Windows as the logging statements use highest LL_WARNING level. This issue has been reported in my fork of that unmaintained MSOpenTech's repo (which I updated to Redis 4.0.2) and has been fixed by decreasing that level to LL_DEBUG. More details: https://github.com/tporadowski/redis/issues/14

This change will be included in the next release (4.0.2.3) or you can get the latest source code and build it for yourself.

Current releases can be found here: https://github.com/tporadowski/redis/releases

An issue was open in the official redis repo 10 months ago about that problem. Unfortunately it seems to be abandoned, and it hasn't been solved yet:

Redis cluster print "WSA_IO_PENDING writing to socket..." continuously, does it matter?

However, that issue may not be related to redis itself, but to the Windows Sockets API, as pointed out by Cy Rossignol in the comments. It's the winsock API that returns that status to the application, as seen in the documentation:

WSA_IO_PENDING (997)

Overlapped operations will complete later.

The application has initiated an overlapped operation that cannot be completed immediately. A completion indication will be given later when the operation has been completed. Note that this error is returned by the operating system, so the error number may change in future releases of Windows.

Maybe it didn't get much attention because it's not a bug, although it's indeed an inconvenience that floods the system logs. In that case, you may not get help there.

Seems like there's no temporary fix. The Windows Redis fork is archived and I don't know if you could get any help there either.