Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Configuring a System
Using Distributed Systems Administration Utilities
Chapter 3 203
— The clog_tail log monitor adds or deletes the package log file
from its list of files to monitor.
Minimizing Message Loss During Failover
When there is a failure on the adoptive node, it takes a finite amount of
time for the clog package to fail over to another cluster member. The
longer this failover time, the more likely that messages could be lost from
the consolidated log. Use the following guidelines to minimize message
loss during failover.
• Configure clients to use the TCP transport instead of the UDP
transport. UDP messages will be lost unconditionally when the
package is down. The TCP protocol contains retry mechanisms,
congestion control, and so on, that help minimize message loss.
• syslog-ng can buffer TCP messages on the client side. The number
of messages buffered is controlled by the syslog-ng
log_fifo_size() setting. This sets an upper limit on the number of
messages that can be buffered. The default
/etc/syslog-ng.conf() file sets log_fifo_size to 10000.
• syslog-ng has a time_reopen() option to configure the time to wait
before a dead connection is reestablished. The
/etc/syslog-ng.conf file has time_reopen() set to 10 seconds.
• Serviceguard offers various configuration options to improve failover
times such as HEARTBEAT_INTERVAL and NODE_TIMEOUT.
Serviceguard Extension for Faster Failover (SGeFF) is also available
to optimize failover times for two-node clusters. Since syslog-ng
itself starts quickly, SGeFF is an ideal candidate for improving
failover times and minimizing message loss.
Configuring a Log Forwarding Client Using clog_wizard
There are two ways to configure a log forwarding client: as a standalone
machine or as a Serviceguard cluster. When configuring a cluster as a log
forwarding client, all the members of the cluster will be configured
identically as clients. The wizard asks the same questions and performs
the same configuration actions for single systems and for clusters. The
examples below show use of the clog wizard on a Serviceguard cluster.
After starting clog_wizard, answer “yes” to the following question:
Do you want to configure log consolidation? (y/n) [y]:
or simply press Enter. The next question is: