On Thu, Jun 24, 2010 at 1:40 PM, Simon Riggs <si...@2ndquadrant.com> wrote: > On Thu, 2010-06-24 at 10:30 -0400, Robert Haas wrote: > >> It lets you set >> the TCP keepalive parameters on the server side, whereas what this >> patch does is let you set them on the client side. Only setting them >> on the client side will allow the client to notice when the server has >> gone away. > > Thank you for explaining. Now I understand. > > It sort of begs the question: why need they be different?
In most cases, they probably don't; in fact, I suspect most people don't bother adjusting these parameters at all. Essentially, they just control the amount of time that can pass before you decide that the other guy is dead. And if the client thinks it's right to declare the server dead after X minutes, it's probably reasonable for the server to declare the client dead after X minutes, too. On the other hand, the client and server may be under different administrative control. What the DBA wants the database to do to avoid running out of connection slots might not be the same as what the application writer wants to do to detect when the database has crashed. For that exact reason, it's actually slightly strange that we make these parameters PGC_USERSET on the server side - but not strange enough that I can get excited about changing it. If an application writer wants to make trouble for the DBA, he certainly has better ways to do it than this... -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
