Applies to: Zorp 3.1 or newer

Symptom

ZCV is not accepting connections from Zorp, but returns the Resource temporarily unavailable error message.

Cause

This error occurs when Zorp and ZCV run on the same machine and communicate via unix domain socket. The value of the '/proc/sys/net/unix/max_dgram_qlen' parameter limits the queue length of the datagrams (i.e. the number of pending connections). However, this parameter applies not only to datagrams, but also to SOCK_STREAM-s. The above error message indicates that the queue is full.
NOTE: The default value of /proc/sys/net/unix/max_dgram_qlen is 10. Zorp 3.1.4 automatically increases this value to 1000.

Solution

Increase the value of the /proc/sys/net/unix/max_dgram_qlen parameter, either directly, or by adding a new entry to the /etc/systctl.conf file.

net/unix/max_dgram_qlen=1000

Additional information / References

For more information on sysctl, see the sysctl.conf(5) and the sysctl(8) manual pages.