21124: Add separate MaxConcurrentRailsRequests config.
[arvados.git] / lib / service / cmd.go
index 4b640c4e4773225ccb0e9312bc18a436552e9cfb..725f86f3bda5c2a82476615ba9ecd6e7a9b7a4fa 100644 (file)
@@ -12,10 +12,12 @@ import (
        "io"
        "net"
        "net/http"
+       "net/http/httptest"
        _ "net/http/pprof"
        "net/url"
        "os"
        "strings"
+       "time"
 
        "git.arvados.org/arvados.git/lib/cmd"
        "git.arvados.org/arvados.git/lib/config"
@@ -45,6 +47,8 @@ type command struct {
        ctx        context.Context // enables tests to shutdown service; no public API yet
 }
 
+var requestQueueDumpCheckInterval = time.Minute
+
 // Command returns a cmd.Handler that loads site config, calls
 // newHandler with the current cluster and node configs, and brings up
 // an http server with the returned handler.
@@ -144,13 +148,32 @@ func (c *command) RunCommand(prog string, args []string, stdin io.Reader, stdout
                return 1
        }
 
+       maxReqs := cluster.API.MaxConcurrentRequests
+       if maxRails := cluster.API.MaxConcurrentRailsRequests; maxRails > 0 &&
+               (maxRails < maxReqs || maxReqs == 0) &&
+               strings.HasSuffix(prog, "controller") {
+               // Ideally, we would accept up to
+               // MaxConcurrentRequests, and apply the
+               // MaxConcurrentRailsRequests limit only for requests
+               // that require calling upstream to RailsAPI. But for
+               // now we make the simplifying assumption that every
+               // controller request causes an upstream RailsAPI
+               // request.
+               maxReqs = maxRails
+       }
        instrumented := httpserver.Instrument(reg, log,
                httpserver.HandlerWithDeadline(cluster.API.RequestTimeout.Duration(),
                        httpserver.AddRequestIDs(
                                httpserver.Inspect(reg, cluster.ManagementToken,
                                        httpserver.LogRequests(
                                                interceptHealthReqs(cluster.ManagementToken, handler.CheckHealth,
-                                                       httpserver.NewRequestLimiter(cluster.API.MaxConcurrentRequests, handler, reg)))))))
+                                                       &httpserver.RequestLimiter{
+                                                               Handler:                    handler,
+                                                               MaxConcurrent:              maxReqs,
+                                                               MaxQueue:                   cluster.API.MaxQueuedRequests,
+                                                               MaxQueueTimeForMinPriority: cluster.API.MaxQueueTimeForLockRequests.Duration(),
+                                                               Priority:                   c.requestPriority,
+                                                               Registry:                   reg}))))))
        srv := &httpserver.Server{
                Server: http.Server{
                        Handler:     ifCollectionInHost(instrumented, instrumented.ServeAPI(cluster.ManagementToken, instrumented)),
@@ -159,7 +182,7 @@ func (c *command) RunCommand(prog string, args []string, stdin io.Reader, stdout
                Addr: listenURL.Host,
        }
        if listenURL.Scheme == "https" || listenURL.Scheme == "wss" {
-               tlsconfig, err := tlsConfigWithCertUpdater(cluster, logger)
+               tlsconfig, err := makeTLSConfig(cluster, logger)
                if err != nil {
                        logger.WithError(err).Errorf("cannot start %s service on %s", c.svcName, listenURL.String())
                        return 1
@@ -189,6 +212,7 @@ func (c *command) RunCommand(prog string, args []string, stdin io.Reader, stdout
                <-handler.Done()
                srv.Close()
        }()
+       go c.requestQueueDumpCheck(cluster, maxReqs, prog, reg, &srv.Server, logger)
        err = srv.Wait()
        if err != nil {
                return 1
@@ -196,6 +220,78 @@ func (c *command) RunCommand(prog string, args []string, stdin io.Reader, stdout
        return 0
 }
 
+// If SystemLogs.RequestQueueDumpDirectory is set, monitor the
+// server's incoming HTTP request queue size. When it exceeds 90% of
+// API.MaxConcurrentRequests, write the /_inspect/requests data to a
+// JSON file in the specified directory.
+func (c *command) requestQueueDumpCheck(cluster *arvados.Cluster, maxReqs int, prog string, reg *prometheus.Registry, srv *http.Server, logger logrus.FieldLogger) {
+       outdir := cluster.SystemLogs.RequestQueueDumpDirectory
+       if outdir == "" || cluster.ManagementToken == "" || maxReqs < 1 {
+               return
+       }
+       logger = logger.WithField("worker", "RequestQueueDump")
+       outfile := outdir + "/" + prog + "-requests.json"
+       for range time.NewTicker(requestQueueDumpCheckInterval).C {
+               mfs, err := reg.Gather()
+               if err != nil {
+                       logger.WithError(err).Warn("error getting metrics")
+                       continue
+               }
+               dump := false
+               for _, mf := range mfs {
+                       if mf.Name != nil && *mf.Name == "arvados_concurrent_requests" && len(mf.Metric) == 1 {
+                               n := int(mf.Metric[0].GetGauge().GetValue())
+                               if n > 0 && n >= maxReqs*9/10 {
+                                       dump = true
+                                       break
+                               }
+                       }
+               }
+               if dump {
+                       req, err := http.NewRequest("GET", "/_inspect/requests", nil)
+                       if err != nil {
+                               logger.WithError(err).Warn("error in http.NewRequest")
+                               continue
+                       }
+                       req.Header.Set("Authorization", "Bearer "+cluster.ManagementToken)
+                       resp := httptest.NewRecorder()
+                       srv.Handler.ServeHTTP(resp, req)
+                       if code := resp.Result().StatusCode; code != http.StatusOK {
+                               logger.WithField("StatusCode", code).Warn("error getting /_inspect/requests")
+                               continue
+                       }
+                       err = os.WriteFile(outfile, resp.Body.Bytes(), 0777)
+                       if err != nil {
+                               logger.WithError(err).Warn("error writing file")
+                               continue
+                       }
+               }
+       }
+}
+
+func (c *command) requestPriority(req *http.Request, queued time.Time) int64 {
+       switch {
+       case req.Method == http.MethodPost && strings.HasPrefix(req.URL.Path, "/arvados/v1/containers/") && strings.HasSuffix(req.URL.Path, "/lock"):
+               // Return 503 immediately instead of queueing. We want
+               // to send feedback to dispatchcloud ASAP to stop
+               // bringing up new containers.
+               return httpserver.MinPriority
+       case req.Method == http.MethodPost && strings.HasPrefix(req.URL.Path, "/arvados/v1/logs"):
+               // "Create log entry" is the most harmless kind of
+               // request to drop. Negative priority is called "low"
+               // in aggregate metrics.
+               return -1
+       case req.Header.Get("Origin") != "":
+               // Handle interactive requests first. Positive
+               // priority is called "high" in aggregate metrics.
+               return 1
+       default:
+               // Zero priority is called "normal" in aggregate
+               // metrics.
+               return 0
+       }
+}
+
 // If an incoming request's target vhost has an embedded collection
 // UUID or PDH, handle it with hTrue, otherwise handle it with
 // hFalse.