hp-snmp-agents keeps listening socket open when receiving HUP signal from logrotate

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Environment

SUSE Linux Enterprise Server 11 Service Pack 1

Situation

hp-snmp-agents-8.7.0.23-18
hp-snmp-agents-9.1.0.57-52.sles11

On SLES11SP1 logrotate send a kill -HUP to the net-snmpd daemon. If the HP support pack is installed, this will restart hp-snmp-agents but the Cmax module will keep its listening port open.
The following error message can be found in /var/log/net-snmpd.log:

cmaX: bind() failed: Address already in use (errno=98)

Checking /proc/<pid-of-snmpd>/fd the following can be seen:

# ls -l /proc/20380/fd
lrwx------ 1 root root 64 May 24 21:13 0 -> /dev/null
lrwx------ 1 root root 64 May 24 21:13 1 -> /dev/null
lrwx------ 1 root root 64 May 24 21:13 10 -> socket:[475794478]
lrwx------ 1 root root 64 May 24 21:26 12 -> socket:[476064548]
lrwx------ 1 root root 64 May 24 21:13 2 -> /dev/null
l-wx------ 1 root root 64 May 24 21:13 3 -> /var/log/net-snmpd.log
lr-x------ 1 root root 64 May 24 21:13 4 -> pipe:[475794401]
l-wx------ 1 root root 64 May 24 21:13 5 -> pipe:[475794401]
lr-x------ 1 root root 64 May 24 21:13 6 -> /etc/sensors.conf

For each received HUP signal, a new socket will get opened.

Resolution

Please contact the Hewlett-Packard support department for a fixed version of hp-snmp-agents.

Workaround for logrotate:

The HUP signal is send from /etc/logrotate.d/net-snmp. At the end of the file there is an entry:

/etc/init.d/net-snmpd try-reload

Please change this to:

/etc/init.d/net-snmpd try-restart

try-restart sends a TERM signal which reliably closes the port and socket.

Cause

This is an issue with the libcmaX64 module of the hp-snmp-agents package.

Disclaimer

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