[SR-Users] how to enable tcp_write_buf?

[Juha Heinanen]

I tried to issue mtree.list command using xmlrpc query that would result
in large response, and got error

Aug 15 18:12:07 char /usr/bin/sip-proxy[10348]: ERROR: <core> [core/tcp_main.c:618]: _wbufq_add(): (221375 bytes): write queue full or timeout  (0, total 0, last write 55534052 s ago)
Aug 15 18:12:07 char /usr/bin/sip-proxy[10348]: ERROR: xmlrpc [xmlrpc.c:811]: send_reply(): Error while sending reply
Aug 15 18:12:07 char /usr/bin/sip-proxy[10367]: ERROR: <core> [core/tcp_main.c:3551]: handle_ser_child(): received CON_ERROR for 0x7f112ad22be0 (id 5), refcnt 3, flags 0x4018

I though that perhaps I could get rid of the error by increasing value
of core var tcp_conn_wq_max.  Description of the var tells:

  Maximum bytes queued for write allowed per connection. Attempting to
  queue more bytes would result in an error and in the connection being
  closed (too slow). If tcp_write_buf is not enabled, it has no effect.

What is tcp_write_buf and how to enable it?  I could not find anything
about it in core cookbook.

-- Juha