From the Slony-I docs (http://www.slony.info/documentation/faq.html) :
"Supposing you experience some sort of network outage, the connection
between slon and database may fail, and the slon may figure this out
long before the PostgreSQL instance it was connected to does. The
result is that there will be some number of idle connections left on
the database server, which won't be closed out until TCP/IP timeouts
complete, which seems to normally take about two hours. For that two
hour period, the slon will try to connect, over and over, and will get
the above fatal message, over and over. "
Speaking as someone who uses Slony quite a lot, this patch sounds very
helpful. Why hasn't libpq had keepalives for years?
Regards,
Peter Geoghegan