Current Behavior

using jmeter to test my route ,and has found some error ,the error message please see the pic .

apisix单机，etcd单机。jmeter压测时 50 thread 1 period 5 loop 执行同一个接口，报错。

maybe change value for "local applications" is not work.
怀疑 "local applications" 刷新逻辑

Expected Behavior

No response

Error Logs

2023/05/23 16:04:22 [warn] 21022#21022: *614008 [lua] debug.lua:198: http_body_filter_phase(): call require("apisix").http_body_filter_phase() return:{} while sending to client, client: 10.202.16.131, server: _, subrequest: "/data-log/general/http2dubbo", upstream: "dubbo://10.202.68.118:20880"
2023/05/23 16:04:22 [warn] 21022#21022: *614008 [lua] debug.lua:190: http_log_phase(): call require("apisix").http_log_phase() args:{} while logging request, client: 10.202.16.131, server: _, subrequest: "/data-log/general/http2dubbo", upstream: "dubbo://10.202.68.118:20880"
2023/05/23 16:04:22 [warn] 21022#21022: *614008 [lua] plugin.lua:399: trace_plugins_info_for_debug(): Apisix-Plugins: request-id, cors while logging request, client: 10.202.16.131, server: _, subrequest: "/data-log/general/http2dubbo", upstream: "dubbo://10.202.68.118:20880"
2023/05/23 16:04:22 [warn] 21022#21022: *614008 [lua] debug.lua:198: http_log_phase(): call require("apisix").http_log_phase() return:{} while logging request, client: 10.202.16.131, server: _, subrequest: "/data-log/general/http2dubbo", upstream: "dubbo://10.202.68.118:20880"
2023/05/23 16:04:22 [error] 24067#24067: *613382 lua entry thread aborted: runtime error: /usr/local/apisix/apisix/discovery/nacos/init.lua:361: attempt to index upvalue 'applications' (a nil value)
stack traceback:
coroutine 0:
/usr/local/apisix/apisix/discovery/nacos/init.lua: in function 'nodes'
/usr/local/apisix/apisix/upstream.lua:259: in function 'set_upstream'
/usr/local/apisix/apisix/init.lua:538: in function 'fun_org'
/usr/local/apisix/apisix/debug.lua:195: in function 'http_access_phase'
access_by_lua(nginx.conf:321):2: in main chunk, client: 10.202.16.131, server: _, request: "POST /data-log/general/http2dubbo HTTP/1.0",

Steps to Reproduce

1. apisix one node , etcd one node & no auth

2. add route for using nacos discovery ,like this:
   {
   "type": "roundrobin",
   "scheme": "http",
   "discovery_type": "nacos",
   "discovery_args": {
   "group_name": "",
   "namespace_id": ""
   },
   "pass_host": "pass",
   "name": "data-log-dubbo",
   "service_name": "data-log",
   "keepalive_pool": {
   "idle_timeout": 60,
   "requests": 1000,
   "size": 320
   }
   }
   route like
   {
   "uri": "/data-log/general/http2dubbo",
   "name": "data-log_xxx",
   "methods": [ "POST" ],
   "plugins": {
   "dubbo-proxy": {
   "method": "invoke",
   "service_name": "com.xxx.proxy.XxxService",
   "service_version": "1.0.0"
   }
   },
   "upstream_id": "data-log-dubbo",
   "status": 1
   }

3. using jmeter 50/200 thread 1 5 loop

Environment

• APISIX version (run apisix version):2.15.1

• Operating system (run uname -a): 3.10.0-1160.80.1.el7.x86_64 change: added doc of how to load plugin. #1 SMP Tue Nov 8 15:48:59 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

• OpenResty / Nginx version (run openresty -V or nginx -V):
  nginx version: openresty/1.21.4.1
  built by gcc 9.3.1 20200408 (Red Hat 9.3.1-2) (GCC)
  built with OpenSSL 1.1.1s 1 Nov 2022
  TLS SNI support enabled
  configure arguments: --prefix=/usr/local/openresty/nginx --with-cc-opt='-O2 -DAPISIX_BASE_VER=1.21.4.1.5 -DNGX_GRPC_CLI_ENGINE_PATH=/usr/local/openresty/libgrpc_engine.so -DNGX_HTTP_GRPC_CLI_ENGINE_PATH=/usr/local/openresty/libgrpc_engine.so -DNGX_LUA_ABORT_AT_PANIC -I/usr/local/openresty/zlib/include -I/usr/local/openresty/pcre/include -I/usr/local/openresty/openssl111/include' --add-module=../ngx_devel_kit-0.3.1 --add-module=../echo-nginx-module-0.62 --add-module=../xss-nginx-module-0.06 --add-module=../ngx_coolkit-0.2 --add-module=../set-misc-nginx-module-0.33 --add-module=../form-input-nginx-module-0.12 --add-module=../encrypted-session-nginx-module-0.09 --add-module=../srcache-nginx-module-0.32 --add-module=../ngx_lua-0.10.21 --add-module=../ngx_lua_upstream-0.07 --add-module=../headers-more-nginx-module-0.33 --add-module=../array-var-nginx-module-0.05 --add-module=../memc-nginx-module-0.19 --add-module=../redis2-nginx-module-0.15 --add-module=../redis-nginx-module-0.3.9 --add-module=../ngx_stream_lua-0.0.11 --with-ld-opt='-Wl,-rpath,/usr/local/openresty/luajit/lib -Wl,-rpath,/usr/local/openresty/wasmtime-c-api/lib -L/usr/local/openresty/zlib/lib -L/usr/local/openresty/pcre/lib -L/usr/local/openresty/openssl111/lib -Wl,-rpath,/usr/local/openresty/zlib/lib:/usr/local/openresty/pcre/lib:/usr/local/openresty/openssl111/lib' --add-module=/tmp/tmp.gwSPZhqVyd/openresty-1.21.4.1/../mod_dubbo-1.0.2 --add-module=/tmp/tmp.gwSPZhqVyd/openresty-1.21.4.1/../ngx_multi_upstream_module-1.1.1 --add-module=/tmp/tmp.gwSPZhqVyd/openresty-1.21.4.1/../apisix-nginx-module-1.12.0 --add-module=/tmp/tmp.gwSPZhqVyd/openresty-1.21.4.1/../apisix-nginx-module-1.12.0/src/stream --add-module=/tmp/tmp.gwSPZhqVyd/openresty-1.21.4.1/../apisix-nginx-module-1.12.0/src/meta --add-module=/tmp/tmp.gwSPZhqVyd/openresty-1.21.4.1/../wasm-nginx-module-0.6.4 --add-module=/tmp/tmp.gwSPZhqVyd/openresty-1.21.4.1/../lua-var-nginx-module-v0.5.3 --add-module=/tmp/tmp.gwSPZhqVyd/openresty-1.21.4.1/../grpc-client-nginx-module-v0.4.0 --with-poll_module --with-pcre-jit --with-stream --with-stream_ssl_module --with-stream_ssl_preread_module --with-http_v2_module --without-mail_pop3_module --without-mail_imap_module --without-mail_smtp_module --with-http_stub_status_module --with-http_realip_module --with-http_addition_module --with-http_auth_request_module --with-http_secure_link_module --with-http_random_index_module --with-http_gzip_static_module --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_mp4_module --with-http_gunzip_module --with-threads --with-compat --with-stream --with-http_ssl_module

• etcd version, if relevant (run curl http://127.0.0.1:9090/v1/server_info):

{"hostname":"TLVM202017071","id":"0880b644-4f19-49e1-af77-1be7d3d7e196","version":"2.15.1","boot_time":1684823930,"etcd_version":"3.5.0"}

• APISIX Dashboard version, if relevant:
• Plugin runner version, for issues related to plugin runners:
• LuaRocks version, for installation issues (run luarocks --version):