My Oracle Support Banner

Excessive CPU Usage by tcp_smtp_server Processes (Doc ID 1904517.1)

Last updated on MAY 05, 2021

Applies to:

Oracle Communications Messaging Server - Version 5.2.0 and later
Information in this document applies to any platform.


We noticed the CPU load of MTA servers increased suddenly after several months of operation. The top 10 processes consuming most of CPU are all tcp_smtp_server processes.

We can workaround the problem by restarting the MTA, but we must also kill the old tcp_smtp_server processes - they do not exit any time soon after dispatcher is restarted. The problem returns in a few days.

[Actually, the problem builds up steadily over time, but becomes noticeable again after a few days.]

Messages continue to deliver properly, but when the server approaches 100% busy, then throughput degrades.

We also noticed a high number of "IDLE" TCP connections shown by netstat - like the following:





To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document
 Additional protection - mapping paranoia and $:|

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.