The MMP Uses SO_LINGER To Cause TCP Rst, Runs Afoul Of Solaris Rst Rate Limit

(Doc ID 2373751.1)

Last updated on APRIL 25, 2018

Applies to:

Oracle Communications Messaging Server - Version 8.0.2 and later
Information in this document applies to any platform.

Symptoms

Using:  Oracle Communications Messaging Server 8.0.2.2.20180130

Running into the default for these Solaris ndd parameters:

tcp_rst_sent_rate_enabled = 1
tcp_rst_sent_rate = 40

You can see how many TCP Rst are NOT sent because of that rate limit by doing:

kstat -p tcp:0:tcpstat:tcp_rst_unsent

Looking at snoop, the Rst packets seem to be going to port 993 on the backends.

If we have a high enough rate of connections between the MMP and the backends, and if the MMP normally sets SO_LINGER such that connections are closed with Rst, it could be a normal connection rate is running afoul of the default for that ndd limit.


Cause

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