I am a MySQL DBA role as usual check the problems and seek a solution.
On one of the production host (MySQL v5.1.53), I started getting errors in this series:

[Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'binlog.000942' at postion 45042

[ERROR] Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013)

[Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'binlog.000928' at postition

[ERROR] Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013)

…

Some expert says you should increase the slave_net_timeout and some says to check value of  relay_log_space_limit but it is default already

slave_net_timeout = 3600
relay_log_space_limit = 0 (unlimited) 
max_allowed_packet = 128MB

I can see no heavy queries …

Why Multi source replication is required?

MySQL has limitation of not allowing to replicate multiple DB’s from different master host on a single slave. MySQL replication had a limitation, fixed with this new release, that said that one slave could have only one master. That is a limiting factor when we are designing our replication environment. There were some “hacks” to make it work, but now there is an official way.

What is multisource replication?
MySQL Multi-Source Replication enables a replication slave to receive transactions from multiple sources simultaneously. Multi-source replication can be used to back up multiple servers to a single server, to merge table shards, and consolidate data from multiple servers to a single server. Multi-source replication does not implement any conflict detection or resolution when applying the transactions, and those tasks are left to the …