> On Apr 20, 2018, at 9:12 AM, Ram <r...@netcore.co.in> wrote: > > I have a very busy postfix server that acts as a relay. It gets mails from an > application and then forwards the mails to the delivery servers on local LAN > > The application can send mails at rate of upto 600 mails per second > Postfix has been configured to accept mails all that quickly, but the > delivery is very poor until inflow stops. Only around 20-50 mails per s > Once the app completes the inflow, then the mails are cleared at a rate of > 1000 mails per second
If you can get the application to send to multiple IP addresses, you could run multiple Postfix instances with multiple queues, each handling a fraction of the load. More queue manager processes might get a larger fraction of the CPU pie. If the local DNS does round-robin A records, and the application calls getaddrinfo() for each connection, a multi-homed Postfix hostname might suffice. Make sure that your transport table is as fast as possible, perhaps none at all, or a texthash file. While the flood is coming in determine whether the congestion is in the "incoming" or "active" queue. I expect the former, but this needs to be confirmed before considering further tuning. -- -- Viktor.