作者:michael2502908531_893 | 来源:互联网 | 2023-09-14 15:57
ROUTER-DEALER是一种最简单的路由方式。将ROUTER和多个DEALER相连接,用一种合适的算法来决定如何分发消息给DEALER。DEALER可以是一个黑洞(只负责处理消
ROUTER-DEALER是一种最简单的路由方式。将ROUTER和多个DEALER相连接,用一种合适的算法来决定如何分发消息给DEALER。DEALER可以是一个黑洞(只负责处理消息,不给任何返回)、代理(将消息转发给其他节点)或是服务(会发送返回信息)。
如果你要求DEALER能够进行回复,那就要保证只有一个ROUTER连接到DEALER,因为DEALER并不知道哪个特定的节点在联系它,如果有多个节点,它会做负载均衡,将消息分发出去。但如果DEALER是一个黑洞,那就可以连接任何数量的节点。
ROUTER-DEALER路由可以用来做什么呢?如果DEALER会将它完成任务的时间回复给ROUTER,那ROUTER就可以知道这个DEALER的处理速度有多快了。因为ROUTER和DEALER都是异步的套接字,所以我们要用zmq_poll()来处理这种情况。
下面例子中的两个DEALER不会返回消息给ROUTER,我们的路由采用加权随机算法:发送两倍多的信息给其中的一个DEALER。
rtdealer.c
// 2015-02-27T11:40+08:00
// ROUTER-to-DEALER example
#include "../zhelpers.h"
#include
#define NBR_WORKERS 10
static void *
worker_task(void *args)
{
void *cOntext= zmq_ctx_new();
void *worker = zmq_socket(context, ZMQ_DEALER);
#if (defined (WIN32))
s_set_id(worker, (intptr_t)args);
#else
s_set_id(worker); // Set a printable identity
#endif
zmq_connect (worker, "tcp://localhost:5671");
int total = 0;
while (1) {
// Tell the broker we‘re ready for work
s_sendmore(worker, "");
s_send(worker, "Hi Boss");
// Get workload from broker, until finished
free(s_recv(worker)); // Envelope delimiter
char *workload = s_recv(worker);
// .skip
int finished = (strcmp(workload, "Fired!") == 0);
free(workload);
if (finished) {
printf("Completed: %d tasks\n", total);
break;
}
total++;
// Do some random work
s_sleep(randof(500) + 1);
}
zmq_close(worker);
zmq_ctx_destroy(context);
return NULL;
}
// .split main task
// While this example runs in a single process, that is just to make
// it easier to start and stop the example. Each thread has its own
// context and conceptually acts as a separate process.
int main(void)
{
void *cOntext= zmq_ctx_new();
void *broker = zmq_socket(context, ZMQ_ROUTER);
zmq_bind(broker, "tcp://*:5671");
srandom((unsigned)time(NULL));
int worker_nbr;
for (worker_nbr = 0; worker_nbr ) {
pthread_t worker;
pthread_create(&worker, NULL, worker_task, (void *)(intptr_t)worker_nbr);
}
// Run for five seconds and then tell workers to end
int64_t end_time = s_clock() + 5000;
int workers_fired = 0;
while (1) {
// Next message gives us least recently used worker
char *identity = s_recv(broker);
s_sendmore(broker, identity);
free(identity);
free(s_recv(broker)); // Envelope delimiter
free(s_recv(broker)); // Response from worker
s_sendmore(broker, "");
// Encourage workers until it‘s time to fire them
if (s_clock() < end_time)
s_send(broker, "Work harder");
else {
s_send(broker, "Fired!");
if (++workers_fired == NBR_WORKERS)
break;
}
}
zmq_close(broker);
zmq_ctx_destroy(context);
return 0;
}
// .until
out:
Completed: 16 tasks
Completed: 20 tasks
Completed: 18 tasks
Completed: 17 tasks
Completed: 21 tasks
Completed: 15 tasks
Completed: 18 tasks
Completed: 21 tasks
Completed: 22 tasks
Completed: 18 tasks