title: What is the default size of datagram queue length in Unix Domain Sockets (AF_UNIX)? Is it configurable?
body: <p>I know the maximum length of a datagram queue length can be found using 
  "cat /proc/sys/net/unix/max_dgram_qlen". </p>
  
  <p>I wanted to know how to find the default value that is set on boot up (like in case of the /proc/sys/net/core/wmem_default for the send buffer size).</p>
  
  <p>Is it possible to increase the value of max_dgram_qlen? What is the upper limit of the same?</p>
  
  <p>My kernel version is 2.6.27.7. I'm new to Unix Domain Socket programming (AF_UNIX).</p>
  
  <p>Thanks in advance for any comments / solutions!</p>