X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/2b152757ce494145c10971c36754c473d21dfcc7..4e2763883588ac691da65ee316a52a052c002aa7:/services/keepstore/keepstore.go

diff --git a/services/keepstore/keepstore.go b/services/keepstore/keepstore.go
index b17cc79e17..80d8670105 100644
--- a/services/keepstore/keepstore.go
+++ b/services/keepstore/keepstore.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
+	"git.curoverse.com/arvados.git/sdk/go/httpserver"
 	"git.curoverse.com/arvados.git/sdk/go/keepclient"
 	"io/ioutil"
 	"log"
@@ -90,6 +91,7 @@ var (
 	TooLongError        = &KeepError{413, "Block is too large"}
 	MethodDisabledError = &KeepError{405, "Method disabled"}
 	ErrNotImplemented   = &KeepError{500, "Unsupported configuration"}
+	ErrClientDisconnect = &KeepError{503, "Client disconnected"}
 )
 
 func (e *KeepError) Error() string {
@@ -145,6 +147,7 @@ func main() {
 		blobSigningKeyFile   string
 		permissionTTLSec     int
 		pidfile              string
+		maxRequests          int
 	)
 	flag.StringVar(
 		&dataManagerTokenFile,
@@ -162,6 +165,11 @@ func main() {
 		"listen",
 		DefaultAddr,
 		"Listening address, in the form \"host:port\". e.g., 10.0.1.24:8000. Omit the host part to listen on all interfaces.")
+	flag.IntVar(
+		&maxRequests,
+		"max-requests",
+		0,
+		"Maximum concurrent requests. When this limit is reached, new requests will receive 503 responses. Note: this limit does not include idle connections from clients using HTTP keepalive, so it does not strictly limit the number of concurrent connections. (default 2 * max-buffers)")
 	flag.BoolVar(
 		&neverDelete,
 		"never-delete",
@@ -302,13 +310,18 @@ func main() {
 		}
 	}
 
+	if maxRequests <= 0 {
+		maxRequests = maxBuffers * 2
+		log.Printf("-max-requests <1 or not specified; defaulting to maxBuffers * 2 == %d", maxRequests)
+	}
+
 	// Start a round-robin VolumeManager with the volumes we have found.
 	KeepVM = MakeRRVolumeManager(volumes)
 
-	// Tell the built-in HTTP server to direct all requests to the REST router.
-	loggingRouter := MakeLoggingRESTRouter()
-	http.HandleFunc("/", func(resp http.ResponseWriter, req *http.Request) {
-		loggingRouter.ServeHTTP(resp, req)
+	// Middleware stack: logger, maxRequests limiter, method handlers
+	http.Handle("/", &LoggingRESTRouter{
+		httpserver.NewRequestLimiter(maxRequests,
+			MakeRESTRouter()),
 	})
 
 	// Set up a TCP listener.