optimizing fetching conf-server-ip, get random ip everytime when ip-list be cached

Author: xiaokai-wang

src/ngx_stream_upsync_module.c

@@ -1650,6 +1650,8 @@ ngx_stream_upsync_etcd_parse_json(void *data)
  if (errorCode != NULL) {
  if (errorCode->valueint == 401) { // trigger reload, we've gone too far with index
  upsync_server->index = 0;
+
+ ngx_del_timer(&upsync_server->upsync_timeout_ev);
  ngx_add_timer(&upsync_server->upsync_ev, 0);
  }
  cJSON_Delete(root);
@@ -1663,7 +1665,10 @@ ngx_stream_upsync_etcd_parse_json(void *data)
 
  if (ngx_memcmp(action->valuestring, "get", 3) != 0) {
  upsync_server->index = 0;
+
+ ngx_del_timer(&upsync_server->upsync_timeout_ev);
  ngx_add_timer(&upsync_server->upsync_ev, 0);
+
  cJSON_Delete(root);
  return NGX_ERROR;
  }
@@ -2509,6 +2514,10 @@ ngx_stream_upsync_connect_handler(ngx_event_t *event)
  ngx_log_error(NGX_LOG_ERR, event->log, 0,
  "upsync_connect_handler: cannot connect to upsync_server: %V ",
  upsync_server->pc.name);
+
+ ngx_del_timer(&upsync_server->upsync_timeout_ev);
+ ngx_add_timer(&upsync_server->upsync_ev, 0);
+
  return;
  }
 
@@ -2969,6 +2978,7 @@ ngx_stream_upsync_dump_server(ngx_stream_upsync_server_t *upsync_server)
 static ngx_int_t
 ngx_stream_upsync_init_server(ngx_event_t *event)
 {
+ ngx_uint_t n = 0, r = 0, cur = 0;
  ngx_pool_t *pool;
  ngx_stream_upsync_ctx_t *ctx;
  ngx_stream_upsync_server_t *upsync_server;
@@ -3029,12 +3039,27 @@ ngx_stream_upsync_init_server(ngx_event_t *event)
  goto valid;
  }
 
+ /* bad method: for get random server*/
+ for (rp = res; rp != NULL; rp = rp->ai_next) {
+ if (rp->ai_family != AF_INET) {
+ continue;
+ }
+
+ n++;
+ }
+
+ r = ngx_random() % n;
  for (rp = res; rp != NULL; rp = rp->ai_next) {
 
  if (rp->ai_family != AF_INET) {
  continue;
  }
 
+ if (cur != r) {
+ cur++;
+ continue;
+ }
+
  sin = ngx_pcalloc(ctx->pool, rp->ai_addrlen);
  if (sin == NULL) {
  goto valid;
@@ -3051,7 +3076,6 @@ ngx_stream_upsync_init_server(ngx_event_t *event)
  if (p == NULL) {
  goto valid;
  }
-
  len = ngx_sock_ntop((struct sockaddr *) sin, rp->ai_addrlen, p, len, 1);
 
  name = ngx_pcalloc(ctx->pool, sizeof(*name));