cmd/tsdbrelay: Drain relay response so that connection is eligible fo…

…r reuse.

cmd/tsdbrelay/main.go

@@ -8,6 +8,7 @@ import (
  "flag"
  "fmt"
  "io"
+ "io/ioutil"
  "net/http"
  "net/http/httptest"
  "net/http/httputil"
@@ -249,6 +250,8 @@ func (rp *relayProxy) relayPut(responseWriter http.ResponseWriter, r *http.Reque
  verbose("bosun relay error: %v", err)
  return
  }
+ // Drain up to 512 bytes and close the body to let the Transport reuse the connection
+ io.CopyN(ioutil.Discard, resp.Body, 512)
  resp.Body.Close()
  verbose("bosun relay success")
  }()
@@ -283,6 +286,8 @@ func (rp *relayProxy) relayPut(responseWriter http.ResponseWriter, r *http.Reque
  collect.Add("additional.puts.error", tags, 1)
  continue
  }
+ // Drain up to 512 bytes and close the body to let the Transport reuse the connection
+ io.CopyN(ioutil.Discard, resp.Body, 512)
  resp.Body.Close()
  verbose("secondary relay success")
  collect.Add("additional.puts.relayed", tags, 1)
@@ -383,6 +388,8 @@ func (rp *relayProxy) relayMetadata(responseWriter http.ResponseWriter, r *http.
  verbose("secondary relay metadata error: %v", err)
  continue
  }
+ // Drain up to 512 bytes and close the body to let the Transport reuse the connection
+ io.CopyN(ioutil.Discard, resp.Body, 512)
  resp.Body.Close()
  verbose("secondary relay metadata success")
  }