bug: failed to run balancer_by_lua*: /usr/local/share/lua/5.1/resty/healthcheck.lua:247: attempt to index field 'targets' (a nil value)

[kuberxy]

Issue description

2021/02/05 14:24:48 [error] 17384#17384: 114551120 failed to run balancer_by_lua: /usr/local/share/lua/5.1/resty/healthcheck.lua:247: attempt to index field 'targets' (a nil value)
stack traceback:
/usr/local/share/lua/5.1/resty/healthcheck.lua:247: in function 'get_target'
/usr/local/share/lua/5.1/resty/healthcheck.lua:424: in function 'get_target_status'
/usr/local/share/lua/5.1/apisix/balancer.lua:68: in function 'fetch_health_nodes'
/usr/local/share/lua/5.1/apisix/balancer.lua:149: in function 'create_obj_fun'
/usr/local/share/lua/5.1/apisix/core/lrucache.lua:92: in function 'lrucache_server_picker'
/usr/local/share/lua/5.1/apisix/balancer.lua:246: in function 'pick_server'
/usr/local/share/lua/5.1/apisix/balancer.lua:276: in function 'load_balancer'
/usr/local/share/lua/5.1/apisix/init.lua:748: in function 'http_balancer_phase'
balancer_by_lua:2: in main chunk while connecting to upstream, client: 183.95.49.7, server: , request:

Environment

• apisix version (cmd: apisix version): 2.1
• OS (cmd: uname -a): 4.15.0-111-generic Ubuntu 18.04
• OpenResty / Nginx version (cmd: nginx -V or openresty -V):openresty/1.15.8.3

[kuberxy]

the same issues:
The targets is nil when call the function get_target after add target

[membphis]

Have you tried the latest version? you are using 2.1 version

[kuberxy]

I did not use the latest version

[spacewander]

Should be fixed by #3240

[panhow]

@spacewander hello , wonder why #3240 can fix this issue ?

[membphis]

the healthcheck will call resty-lock, and the resty-lock will call ngx.sleep, but ngx.sleep can not be called in balancer phase.

so we move it to access phase which allow to call ngx.sleep.