consul rpc error lead fd leaks

consul version: v1.6.6

my app uses consul apis to talk with the consul server, when the below errors appear in the consul log,

2020/07/15 13:54:49 [ERR] http: Request GET /v1/kv/xxxx/xxxxx/xxxx/xxxx?index=8323460&wait=600000ms, error: rpc error making call: EOF from=172.20.0.4:41790
2020/07/15 13:54:49 [ERR] http: Request GET /v1/kv/xxxx/xxxx?index=7391853&recurse=&wait=600000ms, error: rpc error making call: EOF from=172.20.0.4:51744
2020/07/15 13:54:49 [ERR] http: Request GET /v1/health/service/xxxxx?index=8247150&wait=600000ms, error: rpc error making call: EOF from=172.20.0.4:52366

there are lots "sock" entries in the resulf of "lsof -p" and never go away,

xxxxx 43629 xx 1418u sock 0,7 0t0 1266922513 protocol: TCP
xxxxx 43629 xx 1419u sock 0,7 0t0 1239538922 protocol: TCP
xxxxx 43629 xx 1420u sock 0,7 0t0 1268874931 protocol: TCP
xxxxx 43629 xx 1421u sock 0,7 0t0 1446939411 protocol: TCP
xxxxx 43629 xx 1422u sock 0,7 0t0 1472627582 protocol: TCP