core: allow deleting of evaluations (#13492)

* core: add eval delete RPC and core functionality.

* agent: add eval delete HTTP endpoint.

* api: add eval delete API functionality.

* cli: add eval delete command.

* docs: add eval delete website documentation.

.changelog/13492.txt

@@ -0,0 +1,7 @@
+```release-note:improvement
+cli: Added `delete` command to the eval CLI
+```
+
+```release-note:improvement
+agent: Added delete support to the eval HTTP API
+```

api/acl.go

@@ -42,7 +42,7 @@ func (a *ACLPolicies) Delete(policyName string, q *WriteOptions) (*WriteMeta, er
 	if policyName == "" {
 		return nil, fmt.Errorf("missing policy name")
 	}
-	wm, err := a.client.delete("/v1/acl/policy/"+policyName, nil, q)
+	wm, err := a.client.delete("/v1/acl/policy/"+policyName, nil, nil, q)
 	if err != nil {
 		return nil, err
 	}
@@ -142,7 +142,7 @@ func (a *ACLTokens) Delete(accessorID string, q *WriteOptions) (*WriteMeta, erro
 	if accessorID == "" {
 		return nil, fmt.Errorf("missing accessor ID")
 	}
-	wm, err := a.client.delete("/v1/acl/token/"+accessorID, nil, q)
+	wm, err := a.client.delete("/v1/acl/token/"+accessorID, nil, nil, q)
 	if err != nil {
 		return nil, err
 	}

api/api.go

@@ -982,14 +982,15 @@ func (c *Client) write(endpoint string, in, out interface{}, q *WriteOptions) (*
 	return wm, nil
 }
 
-// delete is used to do a DELETE request against an endpoint
-// and serialize/deserialized using the standard Nomad conventions.
-func (c *Client) delete(endpoint string, out interface{}, q *WriteOptions) (*WriteMeta, error) {
+// delete is used to do a DELETE request against an endpoint and
+// serialize/deserialized using the standard Nomad conventions.
+func (c *Client) delete(endpoint string, in, out interface{}, q *WriteOptions) (*WriteMeta, error) {
 	r, err := c.newRequest("DELETE", endpoint)
 	if err != nil {
 		return nil, err
 	}
 	r.setWriteOptions(q)
+	r.obj = in
 	rtt, resp, err := requireOK(c.doRequest(r))
 	if err != nil {
 		return nil, err

api/api_test.go

@@ -107,7 +107,7 @@ func TestRequestTime(t *testing.T) {
 		t.Errorf("bad request time: %d", wm.RequestTime)
 	}
 
-	wm, err = client.delete("/", &out, nil)
+	wm, err = client.delete("/", nil, &out, nil)
 	if err != nil {
 		t.Fatalf("delete err: %v", err)
 	}

api/csi.go

@@ -82,7 +82,7 @@ func (v *CSIVolumes) Register(vol *CSIVolume, w *WriteOptions) (*WriteMeta, erro
 
 // Deregister deregisters a single CSIVolume from Nomad. The volume will not be deleted from the external storage provider.
 func (v *CSIVolumes) Deregister(id string, force bool, w *WriteOptions) error {
-	_, err := v.client.delete(fmt.Sprintf("/v1/volume/csi/%v?force=%t", url.PathEscape(id), force), nil, w)
+	_, err := v.client.delete(fmt.Sprintf("/v1/volume/csi/%v?force=%t", url.PathEscape(id), force), nil, nil, w)
 	return err
 }
 
@@ -104,7 +104,7 @@ func (v *CSIVolumes) Create(vol *CSIVolume, w *WriteOptions) ([]*CSIVolume, *Wri
 // passed as an argument here is for the storage provider's ID, so a volume
 // that's already been deregistered can be deleted.
 func (v *CSIVolumes) Delete(externalVolID string, w *WriteOptions) error {
-	_, err := v.client.delete(fmt.Sprintf("/v1/volume/csi/%v/delete", url.PathEscape(externalVolID)), nil, w)
+	_, err := v.client.delete(fmt.Sprintf("/v1/volume/csi/%v/delete", url.PathEscape(externalVolID)), nil, nil, w)
 	return err
 }
 
@@ -117,7 +117,7 @@ func (v *CSIVolumes) DeleteOpts(req *CSIVolumeDeleteRequest, w *WriteOptions) er
 		w = &WriteOptions{}
 	}
 	w.SetHeadersFromCSISecrets(req.Secrets)
-	_, err := v.client.delete(fmt.Sprintf("/v1/volume/csi/%v/delete", url.PathEscape(req.ExternalVolumeID)), nil, w)
+	_, err := v.client.delete(fmt.Sprintf("/v1/volume/csi/%v/delete", url.PathEscape(req.ExternalVolumeID)), nil, nil, w)
 	return err
 }
 
@@ -125,7 +125,7 @@ func (v *CSIVolumes) DeleteOpts(req *CSIVolumeDeleteRequest, w *WriteOptions) er
 // node. This is used in the case that the node is temporarily lost and the
 // allocations are unable to drop their claims automatically.
 func (v *CSIVolumes) Detach(volID, nodeID string, w *WriteOptions) error {
-	_, err := v.client.delete(fmt.Sprintf("/v1/volume/csi/%v/detach?node=%v", url.PathEscape(volID), nodeID), nil, w)
+	_, err := v.client.delete(fmt.Sprintf("/v1/volume/csi/%v/detach?node=%v", url.PathEscape(volID), nodeID), nil, nil, w)
 	return err
 }
 
@@ -152,7 +152,7 @@ func (v *CSIVolumes) DeleteSnapshot(snap *CSISnapshot, w *WriteOptions) error {
 		w = &WriteOptions{}
 	}
 	w.SetHeadersFromCSISecrets(snap.Secrets)
-	_, err := v.client.delete("/v1/volumes/snapshot?"+qp.Encode(), nil, w)
+	_, err := v.client.delete("/v1/volumes/snapshot?"+qp.Encode(), nil, nil, w)
 	return err
 }
 

api/evaluations.go

@@ -40,6 +40,18 @@ func (e *Evaluations) Info(evalID string, q *QueryOptions) (*Evaluation, *QueryM
 	return &resp, qm, nil
 }
 
+// Delete is used to batch delete evaluations using their IDs.
+func (e *Evaluations) Delete(evalIDs []string, w *WriteOptions) (*WriteMeta, error) {
+	req := EvalDeleteRequest{
+		EvalIDs: evalIDs,
+	}
+	wm, err := e.client.delete("/v1/evaluations", &req, nil, w)
+	if err != nil {
+		return nil, err
+	}
+	return wm, nil
+}
+
 // Allocations is used to retrieve a set of allocations given
 // an evaluation ID.
 func (e *Evaluations) Allocations(evalID string, q *QueryOptions) ([]*AllocationListStub, *QueryMeta, error) {
@@ -108,6 +120,11 @@ type EvaluationStub struct {
 	ModifyTime        int64
 }
 
+type EvalDeleteRequest struct {
+	EvalIDs []string
+	WriteRequest
+}
+
 // EvalIndexSort is a wrapper to sort evaluations by CreateIndex.
 // We reverse the test so that we get the highest index first.
 type EvalIndexSort []*Evaluation

api/evaluations_test.go

@@ -147,6 +147,33 @@ func TestEvaluations_Info(t *testing.T) {
 	}
 }
 
+func TestEvaluations_Delete(t *testing.T) {
+	testutil.Parallel(t)
+
+	testClient, testServer := makeClient(t, nil, nil)
+	defer testServer.Stop()
+
+	// Attempting to delete an evaluation when the eval broker is not paused
+	// should return an error.
+	wm, err := testClient.Evaluations().Delete([]string{"8E231CF4-CA48-43FF-B694-5801E69E22FA"}, nil)
+	require.Nil(t, wm)
+	require.ErrorContains(t, err, "eval broker is enabled")
+
+	// Pause the eval broker, and try to delete an evaluation that does not
+	// exist.
+	schedulerConfig, _, err := testClient.Operator().SchedulerGetConfiguration(nil)
+	require.NoError(t, err)
+	require.NotNil(t, schedulerConfig)
+
+	schedulerConfig.SchedulerConfig.PauseEvalBroker = true
+	schedulerConfigUpdated, _, err := testClient.Operator().SchedulerCASConfiguration(schedulerConfig.SchedulerConfig, nil)
+	require.NoError(t, err)
+	require.True(t, schedulerConfigUpdated.Updated)
+
+	wm, err = testClient.Evaluations().Delete([]string{"8E231CF4-CA48-43FF-B694-5801E69E22FA"}, nil)
+	require.ErrorContains(t, err, "eval not found")
+}
+
 func TestEvaluations_Allocations(t *testing.T) {
 	testutil.Parallel(t)
 	c, s := makeClient(t, nil, nil)

api/jobs.go

@@ -288,7 +288,7 @@ func (j *Jobs) Evaluations(jobID string, q *QueryOptions) ([]*Evaluation, *Query
 // eventually GC'ed from the system. Most callers should not specify purge.
 func (j *Jobs) Deregister(jobID string, purge bool, q *WriteOptions) (string, *WriteMeta, error) {
 	var resp JobDeregisterResponse
-	wm, err := j.client.delete(fmt.Sprintf("/v1/job/%v?purge=%t", url.PathEscape(jobID), purge), &resp, q)
+	wm, err := j.client.delete(fmt.Sprintf("/v1/job/%v?purge=%t", url.PathEscape(jobID), purge), nil, &resp, q)
 	if err != nil {
 		return "", nil, err
 	}
@@ -334,7 +334,7 @@ func (j *Jobs) DeregisterOpts(jobID string, opts *DeregisterOptions, q *WriteOpt
 			opts.Purge, opts.Global, opts.EvalPriority, opts.NoShutdownDelay)
 	}
 
-	wm, err := j.client.delete(endpoint, &resp, q)
+	wm, err := j.client.delete(endpoint, nil, &resp, q)
 	if err != nil {
 		return "", nil, err
 	}

api/namespace.go

@@ -58,7 +58,7 @@ func (n *Namespaces) Register(namespace *Namespace, q *WriteOptions) (*WriteMeta
 
 // Delete is used to delete a namespace
 func (n *Namespaces) Delete(namespace string, q *WriteOptions) (*WriteMeta, error) {
-	wm, err := n.client.delete(fmt.Sprintf("/v1/namespace/%s", namespace), nil, q)
+	wm, err := n.client.delete(fmt.Sprintf("/v1/namespace/%s", namespace), nil, nil, q)
 	if err != nil {
 		return nil, err
 	}

api/quota.go

@@ -90,7 +90,7 @@ func (q *Quotas) Register(spec *QuotaSpec, qo *WriteOptions) (*WriteMeta, error)
 
 // Delete is used to delete a quota spec
 func (q *Quotas) Delete(quota string, qo *WriteOptions) (*WriteMeta, error) {
-	wm, err := q.client.delete(fmt.Sprintf("/v1/quota/%s", quota), nil, qo)
+	wm, err := q.client.delete(fmt.Sprintf("/v1/quota/%s", quota), nil, nil, qo)
 	if err != nil {
 		return nil, err
 	}

api/raw.go

@@ -34,5 +34,5 @@ func (raw *Raw) Write(endpoint string, in, out interface{}, q *WriteOptions) (*W
 // Delete is used to do a DELETE request against an endpoint
 // and serialize/deserialized using the standard Nomad conventions.
 func (raw *Raw) Delete(endpoint string, out interface{}, q *WriteOptions) (*WriteMeta, error) {
-	return raw.c.delete(endpoint, out, q)
+	return raw.c.delete(endpoint, nil, out, q)
 }

api/sentinel.go

@@ -39,7 +39,7 @@ func (a *SentinelPolicies) Delete(policyName string, q *WriteOptions) (*WriteMet
 	if policyName == "" {
 		return nil, fmt.Errorf("missing policy name")
 	}
-	wm, err := a.client.delete("/v1/sentinel/policy/"+policyName, nil, q)
+	wm, err := a.client.delete("/v1/sentinel/policy/"+policyName, nil, nil, q)
 	if err != nil {
 		return nil, err
 	}

api/services.go

@@ -122,7 +122,7 @@ func (s *Services) Get(serviceName string, q *QueryOptions) ([]*ServiceRegistrat
 // by its service name and service ID.
 func (s *Services) Delete(serviceName, serviceID string, q *WriteOptions) (*WriteMeta, error) {
 	path := fmt.Sprintf("/v1/service/%s/%s", url.PathEscape(serviceName), url.PathEscape(serviceID))
-	wm, err := s.client.delete(path, nil, q)
+	wm, err := s.client.delete(path, nil, nil, q)
 	if err != nil {
 		return nil, err
 	}

client/client_test.go

@@ -507,7 +507,7 @@ func TestClient_WatchAllocs(t *testing.T) {
 	})
 
 	// Delete one allocation
-	if err := state.DeleteEval(103, nil, []string{alloc1.ID}); err != nil {
+	if err := state.DeleteEval(103, nil, []string{alloc1.ID}, false); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 

command/agent/eval_endpoint.go

@@ -1,16 +1,29 @@
 package agent
 
 import (
+	"fmt"
 	"net/http"
 	"strings"
 
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
+// EvalsRequest is the entry point for /v1/evaluations and is responsible for
+// handling both the listing of evaluations, and the bulk deletion of
+// evaluations. The latter is a dangerous operation and should use the
+// eval delete command to perform this.
 func (s *HTTPServer) EvalsRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
-	if req.Method != "GET" {
-		return nil, CodedError(405, ErrInvalidMethod)
+	switch req.Method {
+	case http.MethodGet:
+		return s.evalsListRequest(resp, req)
+	case http.MethodDelete:
+		return s.evalsDeleteRequest(resp, req)
+	default:
+		return nil, CodedError(http.StatusMethodNotAllowed, ErrInvalidMethod)
 	}
+}
+
+func (s *HTTPServer) evalsListRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
 
 	args := structs.EvalListRequest{}
 	if s.parse(resp, req, &args.Region, &args.QueryOptions) {
@@ -33,6 +46,37 @@ func (s *HTTPServer) EvalsRequest(resp http.ResponseWriter, req *http.Request) (
 	return out.Evaluations, nil
 }
 
+func (s *HTTPServer) evalsDeleteRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+
+	var args structs.EvalDeleteRequest
+
+	if err := decodeBody(req, &args); err != nil {
+		return nil, CodedError(http.StatusBadRequest, err.Error())
+	}
+
+	numIDs := len(args.EvalIDs)
+
+	// Ensure the number of evaluation IDs included in the request is within
+	// bounds.
+	if numIDs < 1 {
+		return nil, CodedError(http.StatusBadRequest, "request does not include any evaluation IDs")
+	} else if numIDs > structs.MaxUUIDsPerWriteRequest {
+		return nil, CodedError(http.StatusBadRequest, fmt.Sprintf(
+			"request includes %v evaluations IDs, must be %v or fewer",
+			numIDs, structs.MaxUUIDsPerWriteRequest))
+	}
+
+	// Pass the write request to populate all meta fields.
+	s.parseWriteRequest(req, &args.WriteRequest)
+
+	var reply structs.EvalDeleteResponse
+	if err := s.agent.RPC(structs.EvalDeleteRPCMethod, &args, &reply); err != nil {
+		return nil, err
+	}
+	setIndex(resp, reply.Index)
+	return nil, nil
+}
+
 func (s *HTTPServer) EvalSpecificRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
 	path := strings.TrimPrefix(req.URL.Path, "/v1/evaluation/")
 	switch {

command/agent/eval_endpoint_test.go

@@ -6,7 +6,9 @@ import (
 	"net/http/httptest"
 	"testing"
 
+	"github.com/hashicorp/nomad/api"
 	"github.com/hashicorp/nomad/ci"
+	"github.com/hashicorp/nomad/helper/uuid"
 	"github.com/hashicorp/nomad/nomad/mock"
 	"github.com/hashicorp/nomad/nomad/structs"
 	"github.com/stretchr/testify/require"
@@ -110,6 +112,135 @@ func TestHTTP_EvalPrefixList(t *testing.T) {
 	})
 }
 
+func TestHTTP_EvalsDelete(t *testing.T) {
+	ci.Parallel(t)
+
+	testCases := []struct {
+		testFn func()
+		name   string
+	}{
+		{
+			testFn: func() {
+				httpTest(t, nil, func(s *TestAgent) {
+
+					// Create an empty request object which doesn't contain any
+					// eval IDs.
+					deleteReq := api.EvalDeleteRequest{}
+					buf := encodeReq(&deleteReq)
+
+					// Generate the HTTP request.
+					req, err := http.NewRequest(http.MethodDelete, "/v1/evaluations", buf)
+					require.NoError(t, err)
+					respW := httptest.NewRecorder()
+
+					// Make the request and check the response.
+					obj, err := s.Server.EvalsRequest(respW, req)
+					require.Equal(t,
+						CodedError(http.StatusBadRequest, "request does not include any evaluation IDs"), err)
+					require.Nil(t, obj)
+				})
+			},
+			name: "too few eval IDs",
+		},
+		{
+			testFn: func() {
+				httpTest(t, nil, func(s *TestAgent) {
+
+					deleteReq := api.EvalDeleteRequest{EvalIDs: make([]string, 8000)}
+
+					// Generate a UUID and add it 8000 times to the eval ID
+					// request array.
+					evalID := uuid.Generate()
+
+					for i := 0; i < 8000; i++ {
+						deleteReq.EvalIDs[i] = evalID
+					}
+
+					buf := encodeReq(&deleteReq)
+
+					// Generate the HTTP request.
+					req, err := http.NewRequest(http.MethodDelete, "/v1/evaluations", buf)
+					require.NoError(t, err)
+					respW := httptest.NewRecorder()
+
+					// Make the request and check the response.
+					obj, err := s.Server.EvalsRequest(respW, req)
+					require.Equal(t,
+						CodedError(http.StatusBadRequest,
+							"request includes 8000 evaluations IDs, must be 7281 or fewer"), err)
+					require.Nil(t, obj)
+				})
+			},
+			name: "too many eval IDs",
+		},
+		{
+			testFn: func() {
+				httpTest(t, func(c *Config) {
+					c.NomadConfig.DefaultSchedulerConfig.PauseEvalBroker = true
+				}, func(s *TestAgent) {
+
+					// Generate a request with an eval ID that doesn't exist
+					// within state.
+					deleteReq := api.EvalDeleteRequest{EvalIDs: []string{uuid.Generate()}}
+					buf := encodeReq(&deleteReq)
+
+					// Generate the HTTP request.
+					req, err := http.NewRequest(http.MethodDelete, "/v1/evaluations", buf)
+					require.NoError(t, err)
+					respW := httptest.NewRecorder()
+
+					// Make the request and check the response.
+					obj, err := s.Server.EvalsRequest(respW, req)
+					require.Contains(t, err.Error(), "eval not found")
+					require.Nil(t, obj)
+				})
+			},
+			name: "eval doesn't exist",
+		},
+		{
+			testFn: func() {
+				httpTest(t, func(c *Config) {
+					c.NomadConfig.DefaultSchedulerConfig.PauseEvalBroker = true
+				}, func(s *TestAgent) {
+
+					// Upsert an eval into state.
+					mockEval := mock.Eval()
+
+					err := s.Agent.server.State().UpsertEvals(
+						structs.MsgTypeTestSetup, 10, []*structs.Evaluation{mockEval})
+					require.NoError(t, err)
+
+					// Generate a request with the ID of the eval previously upserted.
+					deleteReq := api.EvalDeleteRequest{EvalIDs: []string{mockEval.ID}}
+					buf := encodeReq(&deleteReq)
+
+					// Generate the HTTP request.
+					req, err := http.NewRequest(http.MethodDelete, "/v1/evaluations", buf)
+					require.NoError(t, err)
+					respW := httptest.NewRecorder()
+
+					// Make the request and check the response.
+					obj, err := s.Server.EvalsRequest(respW, req)
+					require.Nil(t, err)
+					require.Nil(t, obj)
+
+					// Ensure the eval is not found.
+					readEval, err := s.Agent.server.State().EvalByID(nil, mockEval.ID)
+					require.NoError(t, err)
+					require.Nil(t, readEval)
+				})
+			},
+			name: "successfully delete eval",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			tc.testFn()
+		})
+	}
+}
+
 func TestHTTP_EvalAllocations(t *testing.T) {
 	ci.Parallel(t)
 	httpTest(t, nil, func(s *TestAgent) {

command/commands.go

@@ -265,6 +265,11 @@ func Commands(metaPtr *Meta, agentUi cli.Ui) map[string]cli.CommandFactory {
 				Meta: meta,
 			}, nil
 		},
+		"eval delete": func() (cli.Command, error) {
+			return &EvalDeleteCommand{
+				Meta: meta,
+			}, nil
+		},
 		"eval list": func() (cli.Command, error) {
 			return &EvalListCommand{
 				Meta: meta,

command/eval.go

@@ -1,8 +1,10 @@
 package command
 
 import (
+	"fmt"
 	"strings"
 
+	"github.com/hashicorp/nomad/api"
 	"github.com/mitchellh/cli"
 )
 
@@ -19,10 +21,18 @@ Usage: nomad eval <subcommand> [options] [args]
   detail but can be useful for debugging placement failures when the cluster
   does not have the resources to run a given job.
 
+  List evaluations:
+
+      $ nomad eval list
+
   Examine an evaluations status:
 
       $ nomad eval status <eval-id>
 
+  Delete evaluations:
+
+      $ nomad eval delete <eval-id>
+
   Please see the individual subcommand help for detailed usage information.
 `
 
@@ -35,6 +45,24 @@ func (f *EvalCommand) Synopsis() string {
 
 func (f *EvalCommand) Name() string { return "eval" }
 
-func (f *EvalCommand) Run(args []string) int {
-	return cli.RunResultHelp
+func (f *EvalCommand) Run(_ []string) int { return cli.RunResultHelp }
+
+// outputEvalList is a helper which outputs an array of evaluations as a list
+// to the UI with key information such as ID and status.
+func outputEvalList(ui cli.Ui, evals []*api.Evaluation, length int) {
+
+	out := make([]string, len(evals)+1)
+	out[0] = "ID|Priority|Triggered By|Job ID|Status|Placement Failures"
+	for i, eval := range evals {
+		failures, _ := evalFailureStatus(eval)
+		out[i+1] = fmt.Sprintf("%s|%d|%s|%s|%s|%s",
+			limit(eval.ID, length),
+			eval.Priority,
+			eval.TriggeredBy,
+			eval.JobID,
+			eval.Status,
+			failures,
+		)
+	}
+	ui.Output(formatList(out))
 }

command/eval_delete.go

@@ -0,0 +1,406 @@
+package command
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/hashicorp/nomad/api"
+	"github.com/hashicorp/nomad/api/contexts"
+	"github.com/posener/complete"
+)
+
+type EvalDeleteCommand struct {
+	Meta
+
+	filter string
+	yes    bool
+
+	// deleteByArg is set when the command is deleting an evaluation that has
+	// been passed as an argument. This avoids need for confirmation.
+	deleteByArg bool
+
+	// numDeleted tracks the total evaluations deleted in a single run of this
+	// command. It provides a way to output this information to the user at the
+	// command completion.
+	numDeleted int
+
+	// client is the lazy-loaded API client and is stored here, so we don't
+	// need to pass it to multiple functions.
+	client *api.Client
+}
+
+func (e *EvalDeleteCommand) Help() string {
+	helpText := `
+Usage: nomad eval delete [options] <evaluation>
+
+  Delete an evaluation by ID. If the evaluation ID is omitted, this command
+  will use the filter flag to identify and delete a set of evaluations. If ACLs
+  are enabled, this command requires a management ACL token.
+
+  This command should be used cautiously and only in outage situations where
+  there is a large backlog of evaluations not being processed. During most
+  normal and outage scenarios, Nomads reconciliation and state management will
+  handle evaluations as needed.
+
+  The eval broker is expected to be paused prior to running this command and
+  un-paused after. This can be done using the following two commands:
+    - nomad operator scheduler set-config -pause-eval-broker=true
+    - nomad operator scheduler set-config -pause-eval-broker=false
+
+General Options:
+
+  ` + generalOptionsUsage(usageOptsNoNamespace) + `
+
+Eval Delete Options:
+
+  -filter
+    Specifies an expression used to filter evaluations by for deletion. When
+    using this flag, it is advisable to ensure the syntax is correct using the
+    eval list command first.
+
+  -yes
+    Bypass the confirmation prompt if an evaluation ID was not provided.
+`
+
+	return strings.TrimSpace(helpText)
+}
+
+func (e *EvalDeleteCommand) Synopsis() string {
+	return "Delete evaluations by ID or using a filter"
+}
+
+func (e *EvalDeleteCommand) AutocompleteFlags() complete.Flags {
+	return mergeAutocompleteFlags(e.Meta.AutocompleteFlags(FlagSetClient),
+		complete.Flags{
+			"-filter": complete.PredictAnything,
+			"-yes":    complete.PredictNothing,
+		})
+}
+
+func (e *EvalDeleteCommand) AutocompleteArgs() complete.Predictor {
+	return complete.PredictFunc(func(a complete.Args) []string {
+		client, err := e.Meta.Client()
+		if err != nil {
+			return nil
+		}
+
+		resp, _, err := client.Search().PrefixSearch(a.Last, contexts.Evals, nil)
+		if err != nil {
+			return []string{}
+		}
+		return resp.Matches[contexts.Evals]
+	})
+}
+
+func (e *EvalDeleteCommand) Name() string { return "eval delete" }
+
+func (e *EvalDeleteCommand) Run(args []string) int {
+
+	flags := e.Meta.FlagSet(e.Name(), FlagSetClient)
+	flags.Usage = func() { e.Ui.Output(e.Help()) }
+	flags.StringVar(&e.filter, "filter", "", "")
+	flags.BoolVar(&e.yes, "yes", false, "")
+	if err := flags.Parse(args); err != nil {
+		return 1
+	}
+
+	args = flags.Args()
+
+	if err := e.verifyArgsAndFlags(args); err != nil {
+		e.Ui.Error(fmt.Sprintf("Error validating command args and flags: %v", err))
+		return 1
+	}
+
+	// Get the HTTP client and store this for use across multiple functions.
+	client, err := e.Meta.Client()
+	if err != nil {
+		e.Ui.Error(fmt.Sprintf("Error initializing client: %s", err))
+		return 1
+	}
+	e.client = client
+
+	// Ensure the eval broker is paused. This check happens multiple times on
+	// the leader, but this check means we can provide quick and actionable
+	// feedback.
+	schedulerConfig, _, err := e.client.Operator().SchedulerGetConfiguration(nil)
+	if err != nil {
+		e.Ui.Error(fmt.Sprintf("Error querying scheduler configuration: %s", err))
+		return 1
+	}
+
+	if !schedulerConfig.SchedulerConfig.PauseEvalBroker {
+		e.Ui.Error("Eval broker is not paused")
+		e.Ui.Output(`To delete evaluations you must first pause the eval broker by running "nomad operator scheduler set-config -pause-eval-broker=true"`)
+		e.Ui.Output(`After the deletion is complete, unpause the eval broker by running "nomad operator scheduler set-config -pause-eval-broker=false"`)
+		return 1
+	}
+
+	// Track the eventual exit code as there are a number of factors that
+	// influence this.
+	var exitCode int
+
+	// Call the correct function in order to handle the operator input
+	// correctly.
+	switch len(args) {
+	case 1:
+		e.deleteByArg = true
+		exitCode, err = e.handleEvalArgDelete(args[0])
+	default:
+
+		// Track the next token, so we can iterate all pages that match the
+		// passed filter.
+		var nextToken string
+
+		// It is possible the filter matches a large number of evaluations
+		// which means we need to run a number of batch deletes. Perform
+		// iteration here rather than recursion in later function, so we avoid
+		// any potential issues with stack size limits.
+		for {
+			exitCode, nextToken, err = e.handleFlagFilterDelete(nextToken)
+
+			// If there is another page of evaluations matching the filter,
+			// iterate the loop and delete the next batch of evals. We pause
+			// for a 500ms rather than just run as fast as the code and machine
+			// possibly can. This means deleting 13million evals will take
+			// roughly 13-15 mins, which seems reasonable. It is worth noting,
+			// we do not expect operators to delete this many evals in a single
+			// run and expect more careful filtering options to be used.
+			if nextToken != "" {
+				time.Sleep(500 * time.Millisecond)
+				continue
+			} else {
+				break
+			}
+		}
+	}
+
+	// Do not exit if we got an error as it's possible this was on the
+	// non-first iteration, and we have therefore deleted some evals.
+	if err != nil {
+		e.Ui.Error(fmt.Sprintf("Error deleting evaluations: %s", err))
+	}
+
+	// Depending on whether we deleted evaluations or not, output a message so
+	// this is clear.
+	if e.numDeleted > 0 {
+		e.Ui.Output(fmt.Sprintf("Successfully deleted %v %s",
+			e.numDeleted, correctGrammar("evaluation", e.numDeleted)))
+	} else if err == nil {
+		e.Ui.Output("No evaluations were deleted")
+	}
+
+	return exitCode
+}
+
+// verifyArgsAndFlags ensures the passed arguments and flags are valid for what
+// this command accepts and can take action on.
+func (e *EvalDeleteCommand) verifyArgsAndFlags(args []string) error {
+
+	numArgs := len(args)
+
+	// The command takes either an argument or filter, but not both.
+	if (e.filter == "" && numArgs < 1) || (e.filter != "" && numArgs > 0) {
+		return errors.New("evaluation ID or filter flag required")
+	}
+
+	// If an argument is supplied, we only accept a single eval ID.
+	if numArgs > 1 {
+		return fmt.Errorf("expected 1 argument, got %v", numArgs)
+	}
+
+	return nil
+}
+
+// handleEvalArgDelete handles deletion and evaluation which was passed via
+// it's ID as a command argument. This is the simplest route to take and
+// doesn't require filtering or batching.
+func (e *EvalDeleteCommand) handleEvalArgDelete(evalID string) (int, error) {
+	evalInfo, _, err := e.client.Evaluations().Info(evalID, nil)
+	if err != nil {
+		return 1, err
+	}
+
+	// Supplying an eval to delete by its ID will always skip verification, so
+	// we don't need to understand the boolean response.
+	code, _, err := e.batchDelete([]*api.Evaluation{evalInfo})
+	return code, err
+}
+
+// handleFlagFilterDelete handles deletion of evaluations discovered using
+// the filter. It is unknown how many will match the operator criteria so
+// this function batches lookup and delete requests into sensible numbers.
+func (e *EvalDeleteCommand) handleFlagFilterDelete(nt string) (int, string, error) {
+
+	evalsToDelete, nextToken, err := e.batchLookupEvals(nt)
+	if err != nil {
+		return 1, "", err
+	}
+
+	numEvalsToDelete := len(evalsToDelete)
+
+	// The filter flags are operator controlled, therefore ensure we
+	// actually found some evals to delete. Otherwise, inform the operator
+	// their flags are potentially incorrect.
+	if numEvalsToDelete == 0 {
+		if e.numDeleted > 0 {
+			return 0, "", nil
+		} else {
+			return 1, "", errors.New("failed to find any evals that matched filter criteria")
+		}
+	}
+
+	if code, actioned, err := e.batchDelete(evalsToDelete); err != nil {
+		return code, "", err
+	} else if !actioned {
+		return code, "", nil
+	}
+
+	e.Ui.Info(fmt.Sprintf("Successfully deleted batch of %v %s",
+		numEvalsToDelete, correctGrammar("evaluation", numEvalsToDelete)))
+
+	return 0, nextToken, nil
+}
+
+// batchLookupEvals handles batched lookup of evaluations using the operator
+// provided filter. The lookup is performed a maximum number of 3 times to
+// ensure their size is limited and the number of evals to delete doesn't exceed
+// the total allowable in a single call.
+//
+// The JSON serialized evaluation API object is 350-380B in size.
+// 2426 * 380B (3.8e-4 MB) = 0.92MB. We may want to make this configurable
+// in the future, but this is counteracted by the CLI logic which will loop
+// until the user tells it to exit, or all evals matching the filter are
+// deleted. 2426 * 3 falls below the maximum limit for eval IDs in a single
+// delete request (set by MaxEvalIDsPerDeleteRequest).
+func (e *EvalDeleteCommand) batchLookupEvals(nextToken string) ([]*api.Evaluation, string, error) {
+
+	var evalsToDelete []*api.Evaluation
+	currentNextToken := nextToken
+
+	// Call List 3 times to accumulate the maximum number if eval IDs supported
+	// in a single Delete request. See math above.
+	for i := 0; i < 3; i++ {
+
+		// Generate the query options using the passed next token and filter. The
+		// per page value is less than the total number we can include in a single
+		// delete request. This keeps the maximum size of the return object at a
+		// reasonable size.
+		opts := api.QueryOptions{
+			Filter:    e.filter,
+			PerPage:   2426,
+			NextToken: currentNextToken,
+		}
+
+		evalList, meta, err := e.client.Evaluations().List(&opts)
+		if err != nil {
+			return nil, "", err
+		}
+
+		if len(evalList) > 0 {
+			evalsToDelete = append(evalsToDelete, evalList...)
+		}
+
+		// Store the next token no matter if it is empty or populated.
+		currentNextToken = meta.NextToken
+
+		// If there is no next token, ensure we exit and avoid any new loops
+		// which will result in duplicate IDs.
+		if currentNextToken == "" {
+			break
+		}
+	}
+
+	return evalsToDelete, currentNextToken, nil
+}
+
+// batchDelete is responsible for deleting the passed evaluations and asking
+// any confirmation questions along the way. It will ask whether the operator
+// want to list the evals before deletion, and optionally ask for confirmation
+// before deleting based on input criteria.
+func (e *EvalDeleteCommand) batchDelete(evals []*api.Evaluation) (int, bool, error) {
+
+	// Ask whether the operator wants to see the list of evaluations before
+	// moving forward with deletion. This will only happen if filters are used
+	// and the confirmation step is not bypassed.
+	if !e.yes && !e.deleteByArg {
+		_, listEvals := e.askQuestion(fmt.Sprintf(
+			"Do you want to list evals (%v) before deletion? [y/N]",
+			len(evals)), "")
+
+		// List the evals for deletion is the user has requested this. It can
+		// be useful when the list is small and targeted, but is maybe best
+		// avoided when deleting large quantities of evals.
+		if listEvals {
+			e.Ui.Output("")
+			outputEvalList(e.Ui, evals, shortId)
+			e.Ui.Output("")
+		}
+	}
+
+	// Generate our list of eval IDs which is required for the API request.
+	ids := make([]string, len(evals))
+
+	for i, eval := range evals {
+		ids[i] = eval.ID
+	}
+
+	// If the user did not wish to bypass the confirmation step, ask this now
+	// and handle the response.
+	if !e.yes && !e.deleteByArg {
+		code, deleteEvals := e.askQuestion(fmt.Sprintf(
+			"Are you sure you want to delete %v evals? [y/N]",
+			len(evals)), "Cancelling eval deletion")
+		e.Ui.Output("")
+
+		if !deleteEvals {
+			return code, deleteEvals, nil
+		}
+	}
+
+	_, err := e.client.Evaluations().Delete(ids, nil)
+	if err != nil {
+		return 1, false, err
+	}
+
+	// Calculate how many total evaluations we have deleted, so we can output
+	// this at the end of the process.
+	curDeleted := e.numDeleted
+	e.numDeleted = curDeleted + len(ids)
+
+	return 0, true, nil
+}
+
+// askQuestion allows the command to ask the operator a question requiring a
+// y/n response. The optional noResp is used when the operator responds no to
+// a question.
+func (e *EvalDeleteCommand) askQuestion(question, noResp string) (int, bool) {
+
+	answer, err := e.Ui.Ask(question)
+	if err != nil {
+		e.Ui.Error(fmt.Sprintf("Failed to parse answer: %v", err))
+		return 1, false
+	}
+
+	if answer == "" || strings.ToLower(answer)[0] == 'n' {
+		if noResp != "" {
+			e.Ui.Output(noResp)
+		}
+		return 0, false
+	} else if strings.ToLower(answer)[0] == 'y' && len(answer) > 1 {
+		e.Ui.Output("For confirmation, an exact ‘y’ is required.")
+		return 0, false
+	} else if answer != "y" {
+		e.Ui.Output("No confirmation detected. For confirmation, an exact 'y' is required.")
+		return 1, false
+	}
+	return 0, true
+}
+
+func correctGrammar(word string, num int) string {
+	if num > 1 {
+		return word + "s"
+	}
+	return word
+}

command/eval_delete_test.go

@@ -0,0 +1,184 @@
+package command
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/nomad/ci"
+	"github.com/mitchellh/cli"
+	"github.com/stretchr/testify/require"
+)
+
+func TestEvalDeleteCommand_Run(t *testing.T) {
+	ci.Parallel(t)
+
+	testCases := []struct {
+		testFn func()
+		name   string
+	}{
+		{
+			testFn: func() {
+
+				testServer, client, url := testServer(t, false, nil)
+				defer testServer.Shutdown()
+
+				// Create the UI and command.
+				ui := cli.NewMockUi()
+				cmd := &EvalDeleteCommand{
+					Meta: Meta{
+						Ui:          ui,
+						flagAddress: url,
+					},
+				}
+
+				// Test basic command input validation.
+				require.Equal(t, 1, cmd.Run([]string{"-address=" + url}))
+				require.Contains(t, ui.ErrorWriter.String(), "Error validating command args and flags")
+				ui.ErrorWriter.Reset()
+				ui.OutputWriter.Reset()
+
+				// Try running the command when the eval broker is not paused.
+				require.Equal(t, 1, cmd.Run([]string{"-address=" + url, "fa3a8c37-eac3-00c7-3410-5ba3f7318fd8"}))
+				require.Contains(t, ui.ErrorWriter.String(), "Eval broker is not paused")
+				ui.ErrorWriter.Reset()
+				ui.OutputWriter.Reset()
+
+				// Paused the eval broker, then try deleting with an eval that
+				// does not exist.
+				schedulerConfig, _, err := client.Operator().SchedulerGetConfiguration(nil)
+				require.NoError(t, err)
+				require.False(t, schedulerConfig.SchedulerConfig.PauseEvalBroker)
+
+				schedulerConfig.SchedulerConfig.PauseEvalBroker = true
+				_, _, err = client.Operator().SchedulerSetConfiguration(schedulerConfig.SchedulerConfig, nil)
+				require.NoError(t, err)
+				require.True(t, schedulerConfig.SchedulerConfig.PauseEvalBroker)
+
+				require.Equal(t, 1, cmd.Run([]string{"-address=" + url, "fa3a8c37-eac3-00c7-3410-5ba3f7318fd8"}))
+				require.Contains(t, ui.ErrorWriter.String(), "eval not found")
+				ui.ErrorWriter.Reset()
+				ui.OutputWriter.Reset()
+			},
+			name: "failure",
+		},
+		{
+			testFn: func() {
+
+				testServer, client, url := testServer(t, false, nil)
+				defer testServer.Shutdown()
+
+				// Create the UI and command.
+				ui := cli.NewMockUi()
+				cmd := &EvalDeleteCommand{
+					Meta: Meta{
+						Ui:          ui,
+						flagAddress: url,
+					},
+				}
+
+				// Paused the eval broker.
+				schedulerConfig, _, err := client.Operator().SchedulerGetConfiguration(nil)
+				require.NoError(t, err)
+				require.False(t, schedulerConfig.SchedulerConfig.PauseEvalBroker)
+
+				schedulerConfig.SchedulerConfig.PauseEvalBroker = true
+				_, _, err = client.Operator().SchedulerSetConfiguration(schedulerConfig.SchedulerConfig, nil)
+				require.NoError(t, err)
+				require.True(t, schedulerConfig.SchedulerConfig.PauseEvalBroker)
+
+				// With the eval broker paused, run a job register several times
+				// to generate evals that will not be acted on.
+				testJob := testJob("eval-delete")
+
+				evalIDs := make([]string, 3)
+				for i := 0; i < 3; i++ {
+					regResp, _, err := client.Jobs().Register(testJob, nil)
+					require.NoError(t, err)
+					require.NotNil(t, regResp)
+					require.NotEmpty(t, regResp.EvalID)
+					evalIDs[i] = regResp.EvalID
+				}
+
+				// Ensure we have three evaluations in state.
+				evalList, _, err := client.Evaluations().List(nil)
+				require.NoError(t, err)
+				require.Len(t, evalList, 3)
+
+				// Attempted to delete one eval using the ID.
+				require.Equal(t, 0, cmd.Run([]string{"-address=" + url, evalIDs[0]}))
+				require.Contains(t, ui.OutputWriter.String(), "Successfully deleted 1 evaluation")
+				ui.ErrorWriter.Reset()
+				ui.OutputWriter.Reset()
+
+				// We modify the number deleted on each command run, so we
+				// need to reset this in order to check the next command
+				// output.
+				cmd.numDeleted = 0
+
+				// Attempted to delete the remaining two evals using a filter
+				// expression.
+				expr := fmt.Sprintf("JobID == %q and Status == \"pending\" ", *testJob.Name)
+				require.Equal(t, 0, cmd.Run([]string{"-address=" + url, "-filter=" + expr}))
+				require.Contains(t, ui.OutputWriter.String(), "Successfully deleted 2 evaluations")
+				ui.ErrorWriter.Reset()
+				ui.OutputWriter.Reset()
+
+				// Ensure we have zero evaluations in state.
+				evalList, _, err = client.Evaluations().List(nil)
+				require.NoError(t, err)
+				require.Len(t, evalList, 0)
+			},
+			name: "successful",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			tc.testFn()
+		})
+	}
+}
+
+func TestEvalDeleteCommand_verifyArgsAndFlags(t *testing.T) {
+	ci.Parallel(t)
+
+	testCases := []struct {
+		inputEvalDeleteCommand *EvalDeleteCommand
+		inputArgs              []string
+		expectedError          error
+		name                   string
+	}{
+		{
+			inputEvalDeleteCommand: &EvalDeleteCommand{
+				filter: `Status == "Pending"`,
+			},
+			inputArgs:     []string{"fa3a8c37-eac3-00c7-3410-5ba3f7318fd8"},
+			expectedError: errors.New("evaluation ID or filter flag required"),
+			name:          "arg and flags",
+		},
+		{
+			inputEvalDeleteCommand: &EvalDeleteCommand{
+				filter: "",
+			},
+			inputArgs:     []string{},
+			expectedError: errors.New("evaluation ID or filter flag required"),
+			name:          "no arg or flags",
+		},
+		{
+			inputEvalDeleteCommand: &EvalDeleteCommand{
+				filter: "",
+			},
+			inputArgs:     []string{"fa3a8c37-eac3-00c7-3410-5ba3f7318fd8", "fa3a8c37-eac3-00c7-3410-5ba3f7318fd9"},
+			expectedError: errors.New("expected 1 argument, got 2"),
+			name:          "multiple args",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			actualError := tc.inputEvalDeleteCommand.verifyArgsAndFlags(tc.inputArgs)
+			require.Equal(t, tc.expectedError, actualError)
+		})
+	}
+}

command/eval_list.go

@@ -167,20 +167,7 @@ func (c *EvalListCommand) Run(args []string) int {
 		length = fullId
 	}
 
-	out := make([]string, len(evals)+1)
-	out[0] = "ID|Priority|Triggered By|Job ID|Status|Placement Failures"
-	for i, eval := range evals {
-		failures, _ := evalFailureStatus(eval)
-		out[i+1] = fmt.Sprintf("%s|%d|%s|%s|%s|%s",
-			limit(eval.ID, length),
-			eval.Priority,
-			eval.TriggeredBy,
-			eval.JobID,
-			eval.Status,
-			failures,
-		)
-	}
-	c.Ui.Output(formatList(out))
+	outputEvalList(c.Ui, evals, length)
 
 	if qm.NextToken != "" {
 		c.Ui.Output(fmt.Sprintf(`

nomad/core_sched.go

@@ -14,13 +14,6 @@ import (
 	"github.com/hashicorp/nomad/scheduler"
 )
 
-var (
-	// maxIdsPerReap is the maximum number of evals and allocations to reap in a
-	// single Raft transaction. This is to ensure that the Raft message does not
-	// become too large.
-	maxIdsPerReap = (1024 * 256) / 36 // 0.25 MB of ids.
-)
-
 // CoreScheduler is a special "scheduler" that is registered
 // as "_core". It is used to run various administrative work
 // across the cluster.
@@ -193,7 +186,7 @@ func (c *CoreScheduler) partitionJobReap(jobs []*structs.Job, leaderACL string)
 			},
 		}
 		requests = append(requests, req)
-		available := maxIdsPerReap
+		available := structs.MaxUUIDsPerWriteRequest
 
 		if remaining := len(jobs) - submittedJobs; remaining > 0 {
 			if remaining <= available {
@@ -359,20 +352,20 @@ func (c *CoreScheduler) evalReap(evals, allocs []string) error {
 	return nil
 }
 
-// partitionEvalReap returns a list of EvalDeleteRequest to make, ensuring a single
+// partitionEvalReap returns a list of EvalReapRequest to make, ensuring a single
 // request does not contain too many allocations and evaluations. This is
 // necessary to ensure that the Raft transaction does not become too large.
-func (c *CoreScheduler) partitionEvalReap(evals, allocs []string) []*structs.EvalDeleteRequest {
-	var requests []*structs.EvalDeleteRequest
+func (c *CoreScheduler) partitionEvalReap(evals, allocs []string) []*structs.EvalReapRequest {
+	var requests []*structs.EvalReapRequest
 	submittedEvals, submittedAllocs := 0, 0
 	for submittedEvals != len(evals) || submittedAllocs != len(allocs) {
-		req := &structs.EvalDeleteRequest{
+		req := &structs.EvalReapRequest{
 			WriteRequest: structs.WriteRequest{
 				Region: c.srv.config.Region,
 			},
 		}
 		requests = append(requests, req)
-		available := maxIdsPerReap
+		available := structs.MaxUUIDsPerWriteRequest
 
 		// Add the allocs first
 		if remaining := len(allocs) - submittedAllocs; remaining > 0 {
@@ -484,7 +477,7 @@ func (c *CoreScheduler) nodeReap(eval *structs.Evaluation, nodeIDs []string) err
 	}
 
 	// Call to the leader to issue the reap
-	for _, ids := range partitionAll(maxIdsPerReap, nodeIDs) {
+	for _, ids := range partitionAll(structs.MaxUUIDsPerWriteRequest, nodeIDs) {
 		req := structs.NodeBatchDeregisterRequest{
 			NodeIDs: ids,
 			WriteRequest: structs.WriteRequest{
@@ -584,7 +577,7 @@ func (c *CoreScheduler) partitionDeploymentReap(deployments []string) []*structs
 			},
 		}
 		requests = append(requests, req)
-		available := maxIdsPerReap
+		available := structs.MaxUUIDsPerWriteRequest
 
 		if remaining := len(deployments) - submittedDeployments; remaining > 0 {
 			if remaining <= available {

nomad/core_sched_test.go

@@ -1852,7 +1852,7 @@ func TestCoreScheduler_PartitionEvalReap(t *testing.T) {
 	core := NewCoreScheduler(s1, snap)
 
 	// Set the max ids per reap to something lower.
-	maxIdsPerReap = 2
+	structs.MaxUUIDsPerWriteRequest = 2
 
 	evals := []string{"a", "b", "c"}
 	allocs := []string{"1", "2", "3"}
@@ -1895,7 +1895,7 @@ func TestCoreScheduler_PartitionDeploymentReap(t *testing.T) {
 	core := NewCoreScheduler(s1, snap)
 
 	// Set the max ids per reap to something lower.
-	maxIdsPerReap = 2
+	structs.MaxUUIDsPerWriteRequest = 2
 
 	deployments := []string{"a", "b", "c"}
 	requests := core.(*CoreScheduler).partitionDeploymentReap(deployments)
@@ -1915,7 +1915,6 @@ func TestCoreScheduler_PartitionDeploymentReap(t *testing.T) {
 }
 
 func TestCoreScheduler_PartitionJobReap(t *testing.T) {
-	ci.Parallel(t)
 
 	s1, cleanupS1 := TestServer(t, nil)
 	defer cleanupS1()
@@ -1929,7 +1928,11 @@ func TestCoreScheduler_PartitionJobReap(t *testing.T) {
 	core := NewCoreScheduler(s1, snap)
 
 	// Set the max ids per reap to something lower.
-	maxIdsPerReap = 2
+	originalMaxUUIDsPerWriteRequest := structs.MaxUUIDsPerWriteRequest
+	structs.MaxUUIDsPerWriteRequest = 2
+	defer func() {
+		structs.MaxUUIDsPerWriteRequest = originalMaxUUIDsPerWriteRequest
+	}()
 
 	jobs := []*structs.Job{mock.Job(), mock.Job(), mock.Job()}
 	requests := core.(*CoreScheduler).partitionJobReap(jobs, "")
@@ -2385,7 +2388,7 @@ func TestCoreScheduler_CSIVolumeClaimGC(t *testing.T) {
 	require.NoError(t, err)
 	index, _ = store.LatestIndex()
 	index++
-	err = store.DeleteEval(index, []string{eval.ID}, []string{alloc1.ID})
+	err = store.DeleteEval(index, []string{eval.ID}, []string{alloc1.ID}, false)
 	require.NoError(t, err)
 
 	// Create a core scheduler and attempt the volume claim GC

nomad/eval_endpoint.go

@@ -1,6 +1,7 @@
 package nomad
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
 	"time"
@@ -391,7 +392,7 @@ func (e *Eval) Reblock(args *structs.EvalUpdateRequest, reply *structs.GenericRe
 }
 
 // Reap is used to cleanup dead evaluations and allocations
-func (e *Eval) Reap(args *structs.EvalDeleteRequest,
+func (e *Eval) Reap(args *structs.EvalReapRequest,
 	reply *structs.GenericResponse) error {
 
 	// Ensure the connection was initiated by another server if TLS is used.
@@ -416,6 +417,150 @@ func (e *Eval) Reap(args *structs.EvalDeleteRequest,
 	return nil
 }
 
+// Delete is used by operators to delete evaluations during severe outages. It
+// differs from Reap while duplicating some behavior to ensure we have the
+// correct controls for user initiated deletions.
+func (e *Eval) Delete(
+	args *structs.EvalDeleteRequest,
+	reply *structs.EvalDeleteResponse) error {
+
+	if done, err := e.srv.forward(structs.EvalDeleteRPCMethod, args, args, reply); done {
+		return err
+	}
+	defer metrics.MeasureSince([]string{"nomad", "eval", "delete"}, time.Now())
+
+	// This RPC endpoint is very destructive and alters Nomad's core state,
+	// meaning only those with management tokens can call it.
+	if aclObj, err := e.srv.ResolveToken(args.AuthToken); err != nil {
+		return err
+	} else if aclObj != nil && !aclObj.IsManagement() {
+		return structs.ErrPermissionDenied
+	}
+
+	// The eval broker must be disabled otherwise Nomad's state will likely get
+	// wild in a very un-fun way.
+	if e.srv.evalBroker.Enabled() {
+		return errors.New("eval broker is enabled; eval broker must be paused to delete evals")
+	}
+
+	// Grab the state snapshot, so we can look up relevant eval information.
+	serverStateSnapshot, err := e.srv.State().Snapshot()
+	if err != nil {
+		return fmt.Errorf("failed to lookup state snapshot: %v", err)
+	}
+	ws := memdb.NewWatchSet()
+
+	// Iterate the evaluations and ensure they are safe to delete. It is
+	// possible passed evals are not safe to delete and would make Nomads state
+	// a little wonky. The nature of the RPC return error, means a single
+	// unsafe eval ID fails the whole call.
+	for _, evalID := range args.EvalIDs {
+
+		evalInfo, err := serverStateSnapshot.EvalByID(ws, evalID)
+		if err != nil {
+			return fmt.Errorf("failed to lookup eval: %v", err)
+		}
+		if evalInfo == nil {
+			return errors.New("eval not found")
+		}
+
+		jobInfo, err := serverStateSnapshot.JobByID(ws, evalInfo.Namespace, evalInfo.JobID)
+		if err != nil {
+			return fmt.Errorf("failed to lookup eval job: %v", err)
+		}
+
+		allocs, err := serverStateSnapshot.AllocsByEval(ws, evalInfo.ID)
+		if err != nil {
+			return fmt.Errorf("failed to lookup eval allocs: %v", err)
+		}
+
+		if !evalDeleteSafe(allocs, jobInfo) {
+			return fmt.Errorf("eval %s is not safe to delete", evalID)
+		}
+	}
+
+	// Generate the Raft request object using the reap request object. This
+	// avoids adding new Raft messages types and follows the existing reap
+	// flow.
+	raftReq := structs.EvalReapRequest{
+		Evals:         args.EvalIDs,
+		UserInitiated: true,
+		WriteRequest:  args.WriteRequest,
+	}
+
+	// Update via Raft.
+	_, index, err := e.srv.raftApply(structs.EvalDeleteRequestType, &raftReq)
+	if err != nil {
+		return err
+	}
+
+	// Update the index and return.
+	reply.Index = index
+	return nil
+}
+
+// evalDeleteSafe ensures an evaluation is safe to delete based on its related
+// allocation and job information. This follows similar, but different rules to
+// the eval reap checking, to ensure evaluations for running allocs or allocs
+// which need the evaluation detail are not deleted.
+func evalDeleteSafe(allocs []*structs.Allocation, job *structs.Job) bool {
+
+	// If the job is deleted, stopped, or dead, all allocs are terminal and
+	// the eval can be deleted.
+	if job == nil || job.Stop || job.Status == structs.JobStatusDead {
+		return true
+	}
+
+	// Iterate the allocations associated to the eval, if any, and check
+	// whether we can delete the eval.
+	for _, alloc := range allocs {
+
+		// If the allocation is still classed as running on the client, or
+		// might be, we can't delete.
+		switch alloc.ClientStatus {
+		case structs.AllocClientStatusRunning, structs.AllocClientStatusUnknown:
+			return false
+		}
+
+		// If the alloc hasn't failed then we don't need to consider it for
+		// rescheduling. Rescheduling needs to copy over information from the
+		// previous alloc so that it can enforce the reschedule policy.
+		if alloc.ClientStatus != structs.AllocClientStatusFailed {
+			continue
+		}
+
+		var reschedulePolicy *structs.ReschedulePolicy
+		tg := job.LookupTaskGroup(alloc.TaskGroup)
+
+		if tg != nil {
+			reschedulePolicy = tg.ReschedulePolicy
+		}
+
+		// No reschedule policy or rescheduling is disabled
+		if reschedulePolicy == nil || (!reschedulePolicy.Unlimited && reschedulePolicy.Attempts == 0) {
+			continue
+		}
+
+		// The restart tracking information has not been carried forward.
+		if alloc.NextAllocation == "" {
+			return false
+		}
+
+		// This task has unlimited rescheduling and the alloc has not been
+		// replaced, so we can't delete the eval yet.
+		if reschedulePolicy.Unlimited {
+			return false
+		}
+
+		// No restarts have been attempted yet.
+		if alloc.RescheduleTracker == nil || len(alloc.RescheduleTracker.Events) == 0 {
+			return false
+		}
+	}
+
+	return true
+}
+
 // List is used to get a list of the evaluations in the system
 func (e *Eval) List(args *structs.EvalListRequest, reply *structs.EvalListResponse) error {
 	if done, err := e.srv.forward("Eval.List", args, args, reply); done {

nomad/eval_endpoint_test.go

@@ -202,7 +202,7 @@ func TestEvalEndpoint_GetEval_Blocking(t *testing.T) {
 
 	// Eval delete triggers watches
 	time.AfterFunc(100*time.Millisecond, func() {
-		err := state.DeleteEval(300, []string{eval2.ID}, []string{})
+		err := state.DeleteEval(300, []string{eval2.ID}, []string{}, false)
 		if err != nil {
 			t.Fatalf("err: %v", err)
 		}
@@ -691,7 +691,7 @@ func TestEvalEndpoint_Reap(t *testing.T) {
 	s1.fsm.State().UpsertEvals(structs.MsgTypeTestSetup, 1000, []*structs.Evaluation{eval1})
 
 	// Reap the eval
-	get := &structs.EvalDeleteRequest{
+	get := &structs.EvalReapRequest{
 		Evals:        []string{eval1.ID},
 		WriteRequest: structs.WriteRequest{Region: "global"},
 	}
@@ -714,6 +714,351 @@ func TestEvalEndpoint_Reap(t *testing.T) {
 	}
 }
 
+func TestEvalEndpoint_Delete(t *testing.T) {
+	ci.Parallel(t)
+
+	testCases := []struct {
+		testFn func()
+		name   string
+	}{
+		{
+			testFn: func() {
+
+				testServer, testServerCleanup := TestServer(t, nil)
+				defer testServerCleanup()
+
+				codec := rpcClient(t, testServer)
+				testutil.WaitForLeader(t, testServer.RPC)
+
+				// Create and upsert an evaluation.
+				mockEval := mock.Eval()
+				require.NoError(t, testServer.fsm.State().UpsertEvals(
+					structs.MsgTypeTestSetup, 10, []*structs.Evaluation{mockEval}))
+
+				// Attempt to delete the eval, which should fail because the
+				// eval broker is not paused.
+				get := &structs.EvalDeleteRequest{
+					EvalIDs:      []string{mockEval.ID},
+					WriteRequest: structs.WriteRequest{Region: "global"},
+				}
+				var resp structs.EvalDeleteResponse
+				err := msgpackrpc.CallWithCodec(codec, structs.EvalDeleteRPCMethod, get, &resp)
+				require.Contains(t, err.Error(), "eval broker is enabled")
+			},
+			name: "unsuccessful delete broker enabled",
+		},
+		{
+			testFn: func() {
+
+				testServer, testServerCleanup := TestServer(t, func(c *Config) {
+					c.NumSchedulers = 0
+				})
+				defer testServerCleanup()
+
+				codec := rpcClient(t, testServer)
+				testutil.WaitForLeader(t, testServer.RPC)
+
+				// Pause the eval broker and update the scheduler config.
+				testServer.evalBroker.SetEnabled(false)
+
+				_, schedulerConfig, err := testServer.fsm.State().SchedulerConfig()
+				require.NoError(t, err)
+				require.NotNil(t, schedulerConfig)
+
+				schedulerConfig.PauseEvalBroker = true
+				require.NoError(t, testServer.fsm.State().SchedulerSetConfig(10, schedulerConfig))
+
+				// Create and upsert an evaluation.
+				mockEval := mock.Eval()
+				require.NoError(t, testServer.fsm.State().UpsertEvals(
+					structs.MsgTypeTestSetup, 10, []*structs.Evaluation{mockEval}))
+
+				// Attempt to delete the eval, which should succeed as the eval
+				// broker is disabled.
+				get := &structs.EvalDeleteRequest{
+					EvalIDs:      []string{mockEval.ID},
+					WriteRequest: structs.WriteRequest{Region: "global"},
+				}
+				var resp structs.EvalDeleteResponse
+				require.NoError(t, msgpackrpc.CallWithCodec(codec, structs.EvalDeleteRPCMethod, get, &resp))
+
+				// Attempt to read the eval from state; this should not be found.
+				ws := memdb.NewWatchSet()
+				respEval, err := testServer.fsm.State().EvalByID(ws, mockEval.ID)
+				require.Nil(t, err)
+				require.Nil(t, respEval)
+			},
+			name: "successful delete without ACLs",
+		},
+		{
+			testFn: func() {
+
+				testServer, rootToken, testServerCleanup := TestACLServer(t, func(c *Config) {
+					c.NumSchedulers = 0
+				})
+				defer testServerCleanup()
+
+				codec := rpcClient(t, testServer)
+				testutil.WaitForLeader(t, testServer.RPC)
+
+				// Pause the eval broker and update the scheduler config.
+				testServer.evalBroker.SetEnabled(false)
+
+				_, schedulerConfig, err := testServer.fsm.State().SchedulerConfig()
+				require.NoError(t, err)
+				require.NotNil(t, schedulerConfig)
+
+				schedulerConfig.PauseEvalBroker = true
+				require.NoError(t, testServer.fsm.State().SchedulerSetConfig(10, schedulerConfig))
+
+				// Create and upsert an evaluation.
+				mockEval := mock.Eval()
+				require.NoError(t, testServer.fsm.State().UpsertEvals(
+					structs.MsgTypeTestSetup, 20, []*structs.Evaluation{mockEval}))
+
+				// Attempt to delete the eval, which should succeed as the eval
+				// broker is disabled, and we are using a management token.
+				get := &structs.EvalDeleteRequest{
+					EvalIDs: []string{mockEval.ID},
+					WriteRequest: structs.WriteRequest{
+						AuthToken: rootToken.SecretID,
+						Region:    "global",
+					},
+				}
+				var resp structs.EvalDeleteResponse
+				require.NoError(t, msgpackrpc.CallWithCodec(codec, structs.EvalDeleteRPCMethod, get, &resp))
+
+				// Attempt to read the eval from state; this should not be found.
+				ws := memdb.NewWatchSet()
+				respEval, err := testServer.fsm.State().EvalByID(ws, mockEval.ID)
+				require.Nil(t, err)
+				require.Nil(t, respEval)
+			},
+			name: "successful delete with ACLs",
+		},
+		{
+			testFn: func() {
+
+				testServer, _, testServerCleanup := TestACLServer(t, func(c *Config) {
+					c.NumSchedulers = 0
+				})
+				defer testServerCleanup()
+
+				codec := rpcClient(t, testServer)
+				testutil.WaitForLeader(t, testServer.RPC)
+
+				// Pause the eval broker.
+				testServer.evalBroker.SetEnabled(false)
+
+				// Create and upsert an evaluation.
+				mockEval := mock.Eval()
+				require.NoError(t, testServer.fsm.State().UpsertEvals(
+					structs.MsgTypeTestSetup, 10, []*structs.Evaluation{mockEval}))
+
+				nonMgntToken := mock.CreatePolicyAndToken(t, testServer.State(), 20, "test-valid",
+					mock.NamespacePolicy(structs.DefaultNamespace, "", []string{acl.NamespaceCapabilitySubmitJob}))
+
+				// Attempt to delete the eval, which should not succeed as we
+				// are using a non-management token.
+				get := &structs.EvalDeleteRequest{
+					EvalIDs: []string{mockEval.ID},
+					WriteRequest: structs.WriteRequest{
+						AuthToken: nonMgntToken.SecretID,
+						Region:    "global",
+					},
+				}
+				var resp structs.EvalDeleteResponse
+				err := msgpackrpc.CallWithCodec(codec, structs.EvalDeleteRPCMethod, get, &resp)
+				require.Contains(t, err.Error(), structs.ErrPermissionDenied.Error())
+			},
+			name: "unsuccessful delete with ACLs incorrect token permissions",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			tc.testFn()
+		})
+	}
+}
+
+func Test_evalDeleteSafe(t *testing.T) {
+	ci.Parallel(t)
+
+	testCases := []struct {
+		inputAllocs    []*structs.Allocation
+		inputJob       *structs.Job
+		expectedResult bool
+		name           string
+	}{
+		{
+			inputAllocs:    nil,
+			inputJob:       nil,
+			expectedResult: true,
+			name:           "job not in state",
+		},
+		{
+			inputAllocs:    nil,
+			inputJob:       &structs.Job{Status: structs.JobStatusDead},
+			expectedResult: true,
+			name:           "job stopped",
+		},
+		{
+			inputAllocs:    nil,
+			inputJob:       &structs.Job{Stop: true},
+			expectedResult: true,
+			name:           "job dead",
+		},
+		{
+			inputAllocs:    []*structs.Allocation{},
+			inputJob:       &structs.Job{Status: structs.JobStatusRunning},
+			expectedResult: true,
+			name:           "no allocs for eval",
+		},
+		{
+			inputAllocs: []*structs.Allocation{
+				{ClientStatus: structs.AllocClientStatusComplete},
+				{ClientStatus: structs.AllocClientStatusRunning},
+			},
+			inputJob:       &structs.Job{Status: structs.JobStatusRunning},
+			expectedResult: false,
+			name:           "running alloc for eval",
+		},
+		{
+			inputAllocs: []*structs.Allocation{
+				{ClientStatus: structs.AllocClientStatusComplete},
+				{ClientStatus: structs.AllocClientStatusUnknown},
+			},
+			inputJob:       &structs.Job{Status: structs.JobStatusRunning},
+			expectedResult: false,
+			name:           "unknown alloc for eval",
+		},
+		{
+			inputAllocs: []*structs.Allocation{
+				{ClientStatus: structs.AllocClientStatusComplete},
+				{ClientStatus: structs.AllocClientStatusLost},
+			},
+			inputJob:       &structs.Job{Status: structs.JobStatusRunning},
+			expectedResult: true,
+			name:           "complete and lost allocs for eval",
+		},
+		{
+			inputAllocs: []*structs.Allocation{
+				{
+					ClientStatus: structs.AllocClientStatusFailed,
+					TaskGroup:    "test",
+				},
+			},
+			inputJob: &structs.Job{
+				Status: structs.JobStatusPending,
+				TaskGroups: []*structs.TaskGroup{
+					{
+						Name:             "test",
+						ReschedulePolicy: nil,
+					},
+				},
+			},
+			expectedResult: true,
+			name:           "failed alloc job without reschedule",
+		},
+		{
+			inputAllocs: []*structs.Allocation{
+				{
+					ClientStatus: structs.AllocClientStatusFailed,
+					TaskGroup:    "test",
+				},
+			},
+			inputJob: &structs.Job{
+				Status: structs.JobStatusPending,
+				TaskGroups: []*structs.TaskGroup{
+					{
+						Name: "test",
+						ReschedulePolicy: &structs.ReschedulePolicy{
+							Unlimited: false,
+							Attempts:  0,
+						},
+					},
+				},
+			},
+			expectedResult: true,
+			name:           "failed alloc job reschedule disabled",
+		},
+		{
+			inputAllocs: []*structs.Allocation{
+				{
+					ClientStatus: structs.AllocClientStatusFailed,
+					TaskGroup:    "test",
+				},
+			},
+			inputJob: &structs.Job{
+				Status: structs.JobStatusPending,
+				TaskGroups: []*structs.TaskGroup{
+					{
+						Name: "test",
+						ReschedulePolicy: &structs.ReschedulePolicy{
+							Unlimited: false,
+							Attempts:  3,
+						},
+					},
+				},
+			},
+			expectedResult: false,
+			name:           "failed alloc next alloc not set",
+		},
+		{
+			inputAllocs: []*structs.Allocation{
+				{
+					ClientStatus:   structs.AllocClientStatusFailed,
+					TaskGroup:      "test",
+					NextAllocation: "4aa4930a-8749-c95b-9c67-5ef29b0fc653",
+				},
+			},
+			inputJob: &structs.Job{
+				Status: structs.JobStatusPending,
+				TaskGroups: []*structs.TaskGroup{
+					{
+						Name: "test",
+						ReschedulePolicy: &structs.ReschedulePolicy{
+							Unlimited: false,
+							Attempts:  3,
+						},
+					},
+				},
+			},
+			expectedResult: false,
+			name:           "failed alloc next alloc set",
+		},
+		{
+			inputAllocs: []*structs.Allocation{
+				{
+					ClientStatus: structs.AllocClientStatusFailed,
+					TaskGroup:    "test",
+				},
+			},
+			inputJob: &structs.Job{
+				Status: structs.JobStatusPending,
+				TaskGroups: []*structs.TaskGroup{
+					{
+						Name: "test",
+						ReschedulePolicy: &structs.ReschedulePolicy{
+							Unlimited: true,
+						},
+					},
+				},
+			},
+			expectedResult: false,
+			name:           "failed alloc job reschedule unlimited",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			actualResult := evalDeleteSafe(tc.inputAllocs, tc.inputJob)
+			require.Equal(t, tc.expectedResult, actualResult)
+		})
+	}
+}
+
 func TestEvalEndpoint_List(t *testing.T) {
 	ci.Parallel(t)
 
@@ -1002,7 +1347,7 @@ func TestEvalEndpoint_List_Blocking(t *testing.T) {
 
 	// Eval deletion triggers watches
 	time.AfterFunc(100*time.Millisecond, func() {
-		if err := state.DeleteEval(3, []string{eval.ID}, nil); err != nil {
+		if err := state.DeleteEval(3, []string{eval.ID}, nil, false); err != nil {
 			t.Fatalf("err: %v", err)
 		}
 	})

nomad/fsm.go

@@ -782,12 +782,12 @@ func (n *nomadFSM) handleUpsertedEval(eval *structs.Evaluation) {
 
 func (n *nomadFSM) applyDeleteEval(buf []byte, index uint64) interface{} {
 	defer metrics.MeasureSince([]string{"nomad", "fsm", "delete_eval"}, time.Now())
-	var req structs.EvalDeleteRequest
+	var req structs.EvalReapRequest
 	if err := structs.Decode(buf, &req); err != nil {
 		panic(fmt.Errorf("failed to decode request: %v", err))
 	}
 
-	if err := n.state.DeleteEval(index, req.Evals, req.Allocs); err != nil {
+	if err := n.state.DeleteEval(index, req.Evals, req.Allocs, req.UserInitiated); err != nil {
 		n.logger.Error("DeleteEval failed", "error", err)
 		return err
 	}

nomad/fsm_test.go

@@ -1160,7 +1160,7 @@ func TestFSM_DeleteEval(t *testing.T) {
 		t.Fatalf("resp: %v", resp)
 	}
 
-	req2 := structs.EvalDeleteRequest{
+	req2 := structs.EvalReapRequest{
 		Evals: []string{eval.ID},
 	}
 	buf, err = structs.Encode(structs.EvalDeleteRequestType, req2)

nomad/node_endpoint_test.go

@@ -2265,7 +2265,7 @@ func TestClientEndpoint_GetClientAllocs_Blocking_GC(t *testing.T) {
 
 	// Delete an allocation
 	time.AfterFunc(100*time.Millisecond, func() {
-		assert.Nil(state.DeleteEval(200, nil, []string{alloc2.ID}))
+		assert.Nil(state.DeleteEval(200, nil, []string{alloc2.ID}, false))
 	})
 
 	req.QueryOptions.MinQueryIndex = 150

nomad/rpc_test.go

@@ -1141,7 +1141,7 @@ func TestRPC_TLS_Enforcement_RPC(t *testing.T) {
 		"Eval.Reblock": &structs.EvalUpdateRequest{
 			WriteRequest: structs.WriteRequest{Region: "global"},
 		},
-		"Eval.Reap": &structs.EvalDeleteRequest{
+		"Eval.Reap": &structs.EvalReapRequest{
 			WriteRequest: structs.WriteRequest{Region: "global"},
 		},
 		"Plan.Submit": &structs.PlanRequest{

nomad/state/state_store.go

@@ -2,6 +2,7 @@ package state
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"reflect"
 	"sort"
@@ -3107,10 +3108,22 @@ func (s *StateStore) updateEvalModifyIndex(txn *txn, index uint64, evalID string
 }
 
 // DeleteEval is used to delete an evaluation
-func (s *StateStore) DeleteEval(index uint64, evals []string, allocs []string) error {
+func (s *StateStore) DeleteEval(index uint64, evals, allocs []string, userInitiated bool) error {
 	txn := s.db.WriteTxn(index)
 	defer txn.Abort()
 
+	// If this deletion has been initiated by an operator, ensure the eval
+	// broker is paused.
+	if userInitiated {
+		_, schedConfig, err := s.schedulerConfigTxn(txn)
+		if err != nil {
+			return err
+		}
+		if schedConfig == nil || !schedConfig.PauseEvalBroker {
+			return errors.New("eval broker is enabled; eval broker must be paused to delete evals")
+		}
+	}
+
 	jobs := make(map[structs.NamespacedID]string, len(evals))
 
 	// evalsTableUpdated and allocsTableUpdated allow us to track whether each
@@ -5890,9 +5903,13 @@ func expiredOneTimeTokenFilter(now time.Time) func(interface{}) bool {
 func (s *StateStore) SchedulerConfig() (uint64, *structs.SchedulerConfiguration, error) {
 	tx := s.db.ReadTxn()
 	defer tx.Abort()
+	return s.schedulerConfigTxn(tx)
+}
+
+func (s *StateStore) schedulerConfigTxn(txn *txn) (uint64, *structs.SchedulerConfiguration, error) {
 
 	// Get the scheduler config
-	c, err := tx.First("scheduler_config", "id")
+	c, err := txn.First("scheduler_config", "id")
 	if err != nil {
 		return 0, nil, fmt.Errorf("failed scheduler config lookup: %s", err)
 	}

nomad/state/state_store_test.go

@@ -4233,7 +4233,7 @@ func TestStateStore_DeleteEval_Eval(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	err = state.DeleteEval(1002, []string{eval1.ID, eval2.ID}, []string{alloc1.ID, alloc2.ID})
+	err = state.DeleteEval(1002, []string{eval1.ID, eval2.ID}, []string{alloc1.ID, alloc2.ID}, false)
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}
@@ -4304,7 +4304,7 @@ func TestStateStore_DeleteEval_Eval(t *testing.T) {
 	// Call the eval delete function with zero length eval and alloc ID arrays.
 	// This should result in the table indexes both staying the same, rather
 	// than updating without cause.
-	require.NoError(t, state.DeleteEval(1010, []string{}, []string{}))
+	require.NoError(t, state.DeleteEval(1010, []string{}, []string{}, false))
 
 	allocsIndex, err := state.Index("allocs")
 	require.NoError(t, err)
@@ -4354,7 +4354,7 @@ func TestStateStore_DeleteEval_ChildJob(t *testing.T) {
 		t.Fatalf("bad: %v", err)
 	}
 
-	err = state.DeleteEval(1002, []string{eval1.ID}, []string{alloc1.ID})
+	err = state.DeleteEval(1002, []string{eval1.ID}, []string{alloc1.ID}, false)
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}
@@ -4386,6 +4386,45 @@ func TestStateStore_DeleteEval_ChildJob(t *testing.T) {
 	}
 }
 
+func TestStateStore_DeleteEval_UserInitiated(t *testing.T) {
+	ci.Parallel(t)
+
+	testState := testStateStore(t)
+
+	// Upsert a scheduler config object, so we have something to check and
+	// modify.
+	schedulerConfig := structs.SchedulerConfiguration{PauseEvalBroker: false}
+	require.NoError(t, testState.SchedulerSetConfig(10, &schedulerConfig))
+
+	// Generate some mock evals and upsert these into state.
+	mockEval1 := mock.Eval()
+	mockEval2 := mock.Eval()
+	require.NoError(t, testState.UpsertEvals(
+		structs.MsgTypeTestSetup, 20, []*structs.Evaluation{mockEval1, mockEval2}))
+
+	mockEvalIDs := []string{mockEval1.ID, mockEval2.ID}
+
+	// Try and delete the evals without pausing the eval broker.
+	err := testState.DeleteEval(30, mockEvalIDs, []string{}, true)
+	require.ErrorContains(t, err, "eval broker is enabled")
+
+	// Pause the eval broker on the scheduler config, and try deleting the
+	// evals again.
+	schedulerConfig.PauseEvalBroker = true
+	require.NoError(t, testState.SchedulerSetConfig(30, &schedulerConfig))
+
+	require.NoError(t, testState.DeleteEval(40, mockEvalIDs, []string{}, true))
+
+	ws := memdb.NewWatchSet()
+	mockEval1Lookup, err := testState.EvalByID(ws, mockEval1.ID)
+	require.NoError(t, err)
+	require.Nil(t, mockEval1Lookup)
+
+	mockEval2Lookup, err := testState.EvalByID(ws, mockEval1.ID)
+	require.NoError(t, err)
+	require.Nil(t, mockEval2Lookup)
+}
+
 func TestStateStore_EvalsByJob(t *testing.T) {
 	ci.Parallel(t)
 

nomad/structs/eval.go

@@ -0,0 +1,24 @@
+package structs
+
+const (
+	// EvalDeleteRPCMethod is the RPC method for batch deleting evaluations
+	// using their IDs.
+	//
+	// Args: EvalDeleteRequest
+	// Reply: EvalDeleteResponse
+	EvalDeleteRPCMethod = "Eval.Delete"
+)
+
+// EvalDeleteRequest is the request object used when operators are manually
+// deleting evaluations. The number of evaluation IDs within the request must
+// not be greater than MaxEvalIDsPerDeleteRequest.
+type EvalDeleteRequest struct {
+	EvalIDs []string
+	WriteRequest
+}
+
+// EvalDeleteResponse is the response object when one or more evaluation are
+// deleted manually by an operator.
+type EvalDeleteResponse struct {
+	WriteMeta
+}

nomad/structs/structs.go

@@ -822,10 +822,20 @@ type EvalUpdateRequest struct {
 	WriteRequest
 }
 
-// EvalDeleteRequest is used for deleting an evaluation.
-type EvalDeleteRequest struct {
+// EvalReapRequest is used for reaping evaluations and allocation. This struct
+// is used by the Eval.Reap RPC endpoint as a request argument, and also when
+// performing eval reap or deletes via Raft. This is because Eval.Reap and
+// Eval.Delete use the same Raft message when performing deletes so we do not
+// need more Raft message types.
+type EvalReapRequest struct {
 	Evals  []string
 	Allocs []string
+
+	// UserInitiated tracks whether this reap request is the result of an
+	// operator request. If this is true, the FSM needs to ensure the eval
+	// broker is paused as the request can include non-terminal allocations.
+	UserInitiated bool
+
 	WriteRequest
 }
 

nomad/structs/uuid.go

@@ -0,0 +1,7 @@
+package structs
+
+// MaxUUIDsPerWriteRequest is the maximum number of UUIDs that can be included
+// within a single write request. This is to ensure that the Raft message does
+// not become too large. The resulting value corresponds to 0.25MB of IDs or
+// 7282 UUID strings.
+var MaxUUIDsPerWriteRequest = (1024 * 256) / 36

nomad/volumewatcher/volumes_watcher_test.go

@@ -108,7 +108,7 @@ func TestVolumeWatch_LeadershipTransition(t *testing.T) {
 
 	// allocation is now invalid
 	index++
-	err = srv.State().DeleteEval(index, []string{}, []string{alloc.ID})
+	err = srv.State().DeleteEval(index, []string{}, []string{alloc.ID}, false)
 	require.NoError(t, err)
 
 	// emit a GC so that we have a volume change that's dropped

website/content/api-docs/evaluations.mdx

@@ -204,6 +204,55 @@ $ curl \
 }
 ```
 
+## Delete Evaluations
+
+This endpoint deletes evaluations. In order to utilise this endpoint the
+eval broker should be paused via the
+[update_scheduler_configuration][operator scheduler update configuration] API
+endpoint.
+
+This API endpoint should be used cautiously and only in outage situations where
+there is a large backlog of evaluations not being processed. During most normal
+and outage scenarios, Nomad's reconciliation and state management will handle
+evaluations as needed.
+
+| Method    | Path              | Produces           |
+| --------- | ----------------- | ------------------ |
+| `DELETE`  | `/v1/evaluations` | `application/json` |
+
+The table below shows this endpoint's support for
+[blocking queries](/api-docs#blocking-queries) and
+[required ACLs](/api-docs#acls).
+
+| Blocking Queries | ACL Required |
+| ---------------- | ------------ |
+| `NO`             | `management` |
+
+### Parameters
+
+- `EvalIDs` `(array<string>: <required>)`- An array of evaluation UUIDs to
+  delete. This must be a full length UUID and not a prefix.
+
+### Sample Payload
+
+```javascript
+{
+  "EvalIDs": [
+    "167ec27d-2e36-979a-280a-a6b920d382db",
+    "6c193955-ac66-42e2-f4c7-f1fc707f1f5e"
+  ]
+}
+```
+
+### Sample Request
+
+```shell-session
+$ curl \
+    --request DELETE \
+    --data @payload.json \
+    https://localhost:4646/v1/evaluations
+```
+
 ## List Allocations for Evaluation
 
 This endpoint lists the allocations created or modified for the given
@@ -332,3 +381,5 @@ $ curl \
   }
 ]
 ```
+
+[update_scheduler_configuration]: api-docs/operator/scheduler#update-scheduler-configuration

website/content/docs/commands/eval/delete.mdx

@@ -0,0 +1,75 @@
+---
+layout: docs
+page_title: 'Commands: eval delete'
+description: |
+  The eval delete command is used to delete evaluations.
+---
+
+# Command: eval delete
+
+The `eval delete` command is used to delete evaluations. It should be used
+cautiously and only in outage situations where there is a large backlog of
+evaluations not being processed. During most normal and outage scenarios,
+Nomad's reconciliation and state management will handle evaluations as needed.
+
+The eval broker is expected to be paused prior to running this command and
+un-paused after. These actions can be performed by the
+[`operator scheduler get-config`][scheduler_get_config]
+and [`operator scheduler set-config`][scheduler_set_config] commands respectively.
+
+## Usage
+
+```plaintext
+nomad eval delete [options] [args]
+```
+
+It takes an optional argument which is the ID of the evaluation to delete. If
+the evaluation ID is omitted, this command will use the filter flag to identify
+and delete a set of evaluations.
+
+When ACLs are enabled, this command requires a `management` token.
+
+## General Options
+
+@include 'general_options.mdx'
+
+## Delete Options
+
+- `-filter`: Specifies an expression used to filter evaluations by for
+  deletion.
+
+- `-yes`: Bypass the confirmation prompt if an evaluation ID was not provided.
+
+## Examples
+
+Delete an evaluation using its ID:
+
+```shell-session
+$ nomad eval delete 9ecffbba-73be-d909-5d7e-ac2694c10e0c
+Successfuly deleted 1 evaluation
+```
+
+Delete all evaluations with status `pending` for the `example` job:
+```shell-session
+$ nomad eval delete -filter='Stauts == "pending" and JobID == "example"'
+Do you want to list evals (3) before deletion? [y/N] y
+
+ID        Priority  Triggered By  Job ID   Status   Placement Failures
+cef92121  50        job-register  example  pending  false
+1c905ca0  50        job-register  example  pending  false
+b9e77692  50        job-register  example  pending  false
+
+Are you sure you want to delete 3 evals? [y/N] y
+
+Successfuly deleted 3 evaluations
+```
+
+Delete all evaluations for the `system` and `service` whilst skipping all
+prompts:
+```shell-session
+$ nomad eval delete -filter='Scheduler == "system" or Scheduler == "service"' -yes
+Successfuly deleted 23 evaluations
+```
+
+[scheduler_get_config]: /docs/commands/operator/scheduler-get-config
+[scheduler_set_config]: /docs/commands/operator/scheduler-set-config

website/content/docs/commands/eval/index.mdx

@@ -15,9 +15,10 @@ Usage: `nomad eval <subcommand> [options]`
 
 Run `nomad eval <subcommand> -h` for help on that subcommand. The following
 subcommands are available:
-
+- [`eval delete`][delete] - Delete evals
 - [`eval list`][list] - List all evals
 - [`eval status`][status] - Display the status of a eval
 
+[delete]: /docs/commands/eval/delete 'Delete evals'
 [list]: /docs/commands/eval/list 'List all evals'
 [status]: /docs/commands/eval/status 'Display the status of a eval'

website/data/docs-nav-data.json

@@ -372,6 +372,10 @@
             "title": "Overview",
             "path": "commands/eval"
           },
+          {
+            "title": "delete",
+            "path": "commands/eval/delete"
+          },
           {
             "title": "list",
             "path": "commands/eval/list"