Starting component `client`: /home/ubuntu/.tiup/components/client/v1.5.2/tiup-client
Connected with driver mysql (5.7.25-TiDB-v5.2.0-alpha-246-g98b2c8804)
Type "help" for help.
经常drop database语句卡住，也杀不掉。
环境：用tiup playground启动的测试环境
log:
[2021/08/08 16:50:12.813 +08:00] [INFO] [region_cache.go:2251] ["[health check] check health error"] [store=127.0.0.1:40031] [error="rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing dial tcp 127.0.0.1:40031: connect: connection refused\""]
[2021/08/08 16:50:12.813 +08:00] [INFO] [grpclogger.go:77] ["attempt to delete child with id 5614696 from a parent (id=5614695) that doesn't currently exist"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.813 +08:00] [INFO] [grpclogger.go:77] ["attempt to delete child with id 5614696 from a parent (id=5614695) that doesn't currently exist"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.813 +08:00] [INFO] [region_request.go:344] ["mark store's regions need be refill"] [id=1] [addr=127.0.0.1:40031] [error="no available connections"]
[2021/08/08 16:50:12.945 +08:00] [WARN] [client_batch.go:363] ["no available connections"] [target=127.0.0.1:40031]
[2021/08/08 16:50:12.945 +08:00] [INFO] [grpclogger.go:77] ["parsed scheme: \"\""] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.945 +08:00] [INFO] [grpclogger.go:77] ["scheme \"\" not registered, fallback to default scheme"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.945 +08:00] [INFO] [grpclogger.go:77] ["ccResolverWrapper: sending update to cc: {[{127.0.0.1:40031 <nil> 0 <nil>}] <nil> <nil>}"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.945 +08:00] [INFO] [grpclogger.go:77] ["ClientConn switching balancer to \"pick_first\""] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.945 +08:00] [INFO] [grpclogger.go:77] ["blockingPicker: the picked transport is not ready, loop back to repick"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.945 +08:00] [WARN] [grpclogger.go:89] ["grpc: addrConn.createTransport failed to connect to {127.0.0.1:40031 <nil> 0 <nil>}. Err :connection error: desc = \"transport: Error while dialing dial tcp 127.0.0.1:40031: connect: connection refused\". Reconnecting..."] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.945 +08:00] [INFO] [region_cache.go:2251] ["[health check] check health error"] [store=127.0.0.1:40031] [error="rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing dial tcp 127.0.0.1:40031: connect: connection refused\""]
[2021/08/08 16:50:12.945 +08:00] [INFO] [grpclogger.go:77] ["attempt to delete child with id 5614698 from a parent (id=5614697) that doesn't currently exist"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.945 +08:00] [INFO] [grpclogger.go:77] ["attempt to delete child with id 5614698 from a parent (id=5614697) that doesn't currently exist"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:12.945 +08:00] [INFO] [region_request.go:344] ["mark store's regions need be refill"] [id=1] [addr=127.0.0.1:40031] [error="no available connections"]
[2021/08/08 16:50:12.966 +08:00] [WARN] [grpclogger.go:89] ["grpc: addrConn.createTransport failed to connect to {127.0.0.1:40031 <nil> 0 <nil>}. Err :connection error: desc = \"transport: Error while dialing dial tcp 127.0.0.1:40031: connect: connection refused\". Reconnecting..."] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.207 +08:00] [WARN] [client_batch.go:363] ["no available connections"] [target=127.0.0.1:40031]
[2021/08/08 16:50:13.208 +08:00] [INFO] [grpclogger.go:77] ["parsed scheme: \"\""] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.208 +08:00] [INFO] [grpclogger.go:77] ["scheme \"\" not registered, fallback to default scheme"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.208 +08:00] [INFO] [grpclogger.go:77] ["ccResolverWrapper: sending update to cc: {[{127.0.0.1:40031 <nil> 0 <nil>}] <nil> <nil>}"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.208 +08:00] [INFO] [grpclogger.go:77] ["ClientConn switching balancer to \"pick_first\""] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.208 +08:00] [INFO] [grpclogger.go:77] ["blockingPicker: the picked transport is not ready, loop back to repick"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.208 +08:00] [WARN] [grpclogger.go:89] ["grpc: addrConn.createTransport failed to connect to {127.0.0.1:40031 <nil> 0 <nil>}. Err :connection error: desc = \"transport: Error while dialing dial tcp 127.0.0.1:40031: connect: connection refused\". Reconnecting..."] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.208 +08:00] [INFO] [region_cache.go:2251] ["[health check] check health error"] [store=127.0.0.1:40031] [error="rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing dial tcp 127.0.0.1:40031: connect: connection refused\""]
[2021/08/08 16:50:13.208 +08:00] [INFO] [grpclogger.go:77] ["attempt to delete child with id 5614700 from a parent (id=5614699) that doesn't currently exist"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.208 +08:00] [INFO] [grpclogger.go:77] ["attempt to delete child with id 5614700 from a parent (id=5614699) that doesn't currently exist"] [system=grpc] [grpc_log=true]
[2021/08/08 16:50:13.208 +08:00] [INFO] [region_request.go:344] ["mark store's regions need be refill"] [id=1] [addr=127.0.0.1:40031] [error="no available connections"]