On Sat, Oct 16, 2010 at 12:43 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
>> But they cannot
>> detect the disconnection in some cases. So replication_timeout needs
>> to be introduced for sync rep.
>
> When exactly don't the keepalives work?
The keepalives don't work at least on linux when the connection is terminated
after sending a packet and before receiving TCP-level ACK. You can confirm
this by unplugging the LAN cable from a client server while running pgbench
on a client. In this case, even if you specify tcp_keepalives_*, backends
would not be able to detect the disconnection. But note that this doesn't
always happen. Which depends on the timing.
Regards,
--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center
