运行以后，报错了，不是必现，现象就是不停的重启。backgroundFlush

[githubtest]

`crypto/tls.(*Conn).readRecord(...)
/usr/local/go/src/crypto/tls/conn.go:573
crypto/tls.(*Conn).Read(0xc0000e2a80, 0xc00143a000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
/usr/local/go/src/crypto/tls/conn.go:1276 +0x165
net/http.(*persistConn).Read(0xc00052e900, 0xc00143a000, 0x1000, 0x1000, 0xc000182480, 0xc000092d40, 0x40b2b5)
/usr/local/go/src/net/http/transport.go:1922 +0x77
bufio.(*Reader).fill(0xc0013a5980)
/usr/local/go/src/bufio/bufio.go:101 +0x108
bufio.(*Reader).Peek(0xc0013a5980, 0x1, 0x0, 0x1, 0x4, 0x1, 0x3)
/usr/local/go/src/bufio/bufio.go:139 +0x4f
net/http.(*persistConn).readLoop(0xc00052e900)
/usr/local/go/src/net/http/transport.go:2083 +0x1a8
created by net/http.(*Transport).dialConn
/usr/local/go/src/net/http/transport.go:1743 +0xc77

goroutine 15 [select]:
github.com/tal-tech/go-zero/core/executors.(*PeriodicalExecutor).backgroundFlush.func1()
/app/vendor/github.com/tal-tech/go-zero/core/executors/periodicalexecutor.go:129 +0x18c
github.com/tal-tech/go-zero/core/threading.RunSafe(0xc0014c8760)
/app/vendor/github.com/tal-tech/go-zero/core/threading/routines.go:32 +0x5f
created by github.com/tal-tech/go-zero/core/threading.GoSafe
/app/vendor/github.com/tal-tech/go-zero/core/threading/routines.go:13 +0x3f

goroutine 157 [select]:
net/http.(*persistConn).writeLoop(0xc00052f320)
/usr/local/go/src/net/http/transport.go:2382 +0xf7
created by net/http.(*Transport).dialConn
/usr/local/go/src/net/http/transport.go:1744 +0xc9c

goroutine 65 [select]:
net/http.(*persistConn).writeLoop(0xc00052e900)
/usr/local/go/src/net/http/transport.go:2382 +0xf7
created by net/http.(*Transport).dialConn
/usr/local/go/src/net/http/transport.go:1744 +0xc9c

goroutine 117 [select]:
net/http.(*persistConn).writeLoop(0xc001563560)
/usr/local/go/src/net/http/transport.go:2382 +0xf7
created by net/http.(*Transport).dialConn
/usr/local/go/src/net/http/transport.go:1744 +0xc9c

goroutine 178 [IO wait]:
internal/poll.runtime_pollWait(0x7f07a865b1b8, 0x72, 0xffffffffffffffff)
/usr/local/go/src/runtime/netpoll.go:222 +0x55
internal/poll.(*pollDesc).wait(0xc0016b4d18, 0x72, 0x1600, 0x1626, 0xffffffffffffffff)
/usr/local/go/src/internal/poll/fd_poll_runtime.go:87 +0x45
internal/poll.(*pollDesc).waitRead(...)
/usr/local/go/src/internal/poll/fd_poll_runtime.go:92
internal/poll.(*FD).Read(0xc0016b4d00, 0xc00168d800, 0x1626, 0x1626, 0x0, 0x0, 0x0)
/usr/local/go/src/internal/poll/fd_unix.go:166 +0x1d5
net.(*netFD).Read(0xc0016b4d00, 0xc00168d800, 0x1626, 0x1626, 0x1621, 0xc00168d800, 0x5)
/usr/local/go/src/net/fd_posix.go:55 +0x4f
net.(*conn).Read(0xc000010210, 0xc00168d800, 0x1626, 0x1626, 0x0, 0x0, 0x0)
/usr/local/go/src/net/net.go:183 +0x91
crypto/tls.(*atLeastReader).Read(0xc0003c3a70, 0xc00168d800, 0x1626, 0x1626, 0xc0000919f8, 0xc000080800, 0x0)
/usr/local/go/src/crypto/tls/conn.go:776 +0x63
bytes.(*Buffer).ReadFrom(0xc0015b7078, 0x10fe400, 0xc0003c3a70, 0x411485, 0xe903c0, 0xf78e40)
/usr/local/go/src/bytes/buffer.go:204 +0xbe
crypto/tls.(*Conn).readFromUntil(0xc0015b6e00, 0x11003e0, 0xc000010210, 0x5, 0xc000010210, 0x203000)
/usr/local/go/src/crypto/tls/conn.go:798 +0xf3
crypto/tls.(*Conn).readRecordOrCCS(0xc0015b6e00, 0x0, 0x0, 0x440c5c)
/usr/local/go/src/crypto/tls/conn.go:605 +0x115
crypto/tls.(*Conn).readRecord(...)
/usr/local/go/src/crypto/tls/conn.go:573
crypto/tls.(*Conn).Read(0xc0015b6e00, 0xc0018da000, 0x1000, 0x1000, 0x0, 0x0, 0x0)
/usr/local/go/src/crypto/tls/conn.go:1276 +0x165
net/http.(*persistConn).Read(0xc00052efc0, 0xc0018da000, 0x1000, 0x1000, 0xc0000a29c0, 0xc000091d40, 0x40b2b5)
/usr/local/go/src/net/http/transport.go:1922 +0x77
bufio.(*Reader).fill(0xc0014e44e0)
/usr/local/go/src/bufio/bufio.go:101 +0x108
bufio.(*Reader).Peek(0xc0014e44e0, 0x1, 0x0, 0x1, 0x4, 0x1, 0x3)
/usr/local/go/src/bufio/bufio.go:139 +0x4f
net/http.(*persistConn).readLoop(0xc00052efc0)
/usr/local/go/src/net/http/transport.go:2083 +0x1a8
created by net/http.(*Transport).dialConn
/usr/local/go/src/net/http/transport.go:1743 +0xc77`

[githubtest]

设置了配置文件里面的timeout可以解决。。。