I have converted a database (on both master and child nodes) for distributed monitoring, and set up the relationship (master - child).
But on the master, I do not see any configuration for child node.

In the logs on the child appears the following message:
16569:20131009:132601.550 NODE 2: sending configuration changes to master node 1 for node 2 datalen 213761451
16569:20131009:132601.649 NODE 2: Error while sending data to Node [1] error: ZBX_TCP_WRITE() failed: [32] Broken pipe

On the the master::
9648:20131009:132601.595 Message size 213761451 exceeds the maximum size 134217728 bytes. Message ignored.
Correspondingly further errors occur, such as:
query failed: [1452] Cannot add or update a child row: a foreign key constraint fails.....
etc.

It seems to me that this is due to the fact that the child node has a large configuration:
Number of hosts (monitored/not monitored/templates) 1521 1316 / 51 / 154
Number of items (monitored/disabled/not supported) 139829 105377 / 33272 / 1180
Number of triggers (enabled/disabled)[problem/unknown/ok] 62535 61227 / 1308 [1571 / 0 / 59656]

And when sending, all this configuration does not fit into 128 MB (function zbx_tcp_recv_ext).

Accordingly, the data can be split into portions, if their total size exceeds ZBX_MAX_RECV_DATA_SIZE, or put this option in the server configuration.