xfonts_probe 方法实现一个循环。 在实现该循环之前,xfonts_probe 将:
检索 xfnts 资源的网络地址资源,如下所示。
/* Get the ip addresses available for this resource */
if (scds_get_netaddr_list(scds_handle, &netaddr)) {
scds_syslog(LOG_ERR,
"No network address resource in resource group.");
scds_close(&scds_handle);
return (1);
}
/* Return an error if there are no network resources */
if (netaddr == NULL || netaddr->num_netaddrs == 0) {
scds_syslog(LOG_ERR,
"No network address resource in resource group.");
return (1);
}
调用 scds_fm_sleep() 并将 Thorough_probe_interval 的值作为超时值传送。 在探测操作之间,该探测程序将休眠,休眠时间为 Thorough_probe_interval 的值。
timeout = scds_get_ext_probe_timeout(scds_handle);
for (;;) {
/*
* sleep for a duration of thorough_probe_interval between
* successive probes.
*/
(void) scds_fm_sleep(scds_handle,
scds_get_rs_thorough_probe_interval(scds_handle));
xfnts_probe 方法将按以下方式实现该循环。
for (ip = 0; ip < netaddr->num_netaddrs; ip++) {
/*
* Grab the hostname and port on which the
* health has to be monitored.
*/
hostname = netaddr->netaddrs[ip].hostname;
port = netaddr->netaddrs[ip].port_proto.port;
/*
* HA-XFS supports only one port and
* hence obtain the port value from the
* first entry in the array of ports.
*/
ht1 = gethrtime(); /* Latch probe start time */
scds_syslog(LOG_INFO, "Probing the service on port: %d.", port);
probe_result =
svc_probe(scds_handle, hostname, port, timeout);
/*
* Update service probe history,
* take action if necessary.
* Latch probe end time.
*/
ht2 = gethrtime();
/* Convert to milliseconds */
dt = (ulong_t)((ht2 - ht1) / 1e6);
/*
* Compute failure history and take
* action if needed
*/
(void) scds_fm_action(scds_handle,
probe_result, (long)dt);
} /* Each net resource */
} /* Keep probing forever */
svc_probe() 函数将实现探测程序逻辑。 从 svc_probe() 返回的值被传送到 scds_fm_action(),以决定是否重新启动应用程序、对资源组进行故障切换或不进行任何操作。