Merge pull request #2 from chen-honggang/dev/add-max-tries

add config: max_tries that limits tries for request to backend ip

Author: StartAgainJ

README.md

@@ -179,4 +179,5 @@ upstream test_upstream {
 |  mr   | N | Switch for metadata route| off |
 |  mr_mode   | N | metadata route fail over mode | 0 |
 |  fail_report   | N | Business-level fail report status code | "" |
+|  max_tries   | N | Limits the number of tries for request to backend ip | 2 |
 

nginx_polaris_module/ngx_http_upstream_polaris_module.cpp

@@ -205,6 +205,9 @@ static ngx_int_t ngx_http_upstream_init_polaris_peer(ngx_http_request_t *r,
   r->upstream->peer.get  = ngx_http_upstream_get_polaris_peer;
   r->upstream->peer.free = ngx_http_upstream_free_polaris_peer;
 
+  if (dcf->max_tries != NGX_CONF_UNSET_UINT) {
+    r->upstream->peer.tries = dcf->max_tries;
+  }
   // control the retry times >= 2.
   if (r->upstream->peer.tries < 2) {
     r->upstream->peer.tries = 2;
@@ -340,6 +343,7 @@ static void *ngx_http_upstream_polaris_create_conf(ngx_conf_t *cf) {
   conf->polaris_metadata_route_enabled = false;
   ngx_str_set(&conf->polaris_fail_status_list, "");
   conf->polaris_fail_status_report_enabled = false;
+  conf->max_tries = NGX_CONF_UNSET_UINT;
 
   return conf;
 }
@@ -584,6 +588,20 @@ static char *ngx_http_upstream_polaris_set_handler(ngx_conf_t *cf, ngx_command_t
 
       continue;
     }
+
+    if (ngx_strncmp(value[i].data, "max_tries=", 10) == 0) {
+      ngx_str_t s = {value[i].len - 10, &value[i].data[10]};
+
+      ngx_int_t max_tries = ngx_atoi(s.data, s.len);
+      if (max_tries < 1 || max_tries > 256) {
+        ngx_conf_log_error(NGX_LOG_ERR, cf, 0,
+                          "dcf->max_tries:%d invalid, only valid in (1-256)",
+                          max_tries);
+        return const_cast<char *>("invalid polaris max_tries");
+      }
+      dcf->max_tries = max_tries;
+      continue;
+    }
   }
 
   dcf->enabled = true;
@@ -645,10 +663,10 @@ static char *ngx_http_upstream_polaris_set_handler(ngx_conf_t *cf, ngx_command_t
   ngx_conf_log_error(
       NGX_LOG_NOTICE, cf, 0,
       "init service_namespace:%s, service_name:%s, timeout: %.2f, mode: %d, "
-      "key: %s, dr: %d, mr_mode: %d, fail_status: %s",
+      "key: %s, dr: %d, mr_mode: %d, fail_status: %s,  max_tries: %d",
       dcf->polaris_service_namespace.data, dcf->polaris_service_name.data, dcf->polaris_timeout,
       dcf->polaris_lb_mode, dcf->polaris_lb_key.data, dcf->polaris_dynamic_route_enabled,
-      dcf->metadata_route_failover_mode, dcf->polaris_fail_status_list.data);
+      dcf->metadata_route_failover_mode, dcf->polaris_fail_status_list.data, dcf->max_tries);
 
   return NGX_CONF_OK;
 }

nginx_polaris_module/ngx_http_upstream_polaris_module.h

@@ -62,6 +62,8 @@ typedef struct {
 
   ngx_http_upstream_init_pt original_init_upstream;
   ngx_http_upstream_init_peer_pt original_init_peer;
+
+  ngx_uint_t max_tries;
 } ngx_http_upstream_polaris_srv_conf_t;
 
 /**