featurebase/test/cluster.go
Seebs 0638101d2a cluster state checking cleanups and fixes
A while back we started just polling the reported cluster state of one node
when starting a cluster for tests. This works fine if we're doing fresh
new etcd queries for every single operation -- but that's insanely
expensive, it turns out.

When we use the watcher, some nodes will report stale data for "a
while", where "a while" appears to be easily a couple dozen milliseconds.
This is probably irrelevant in most real-world cases, because the common
case (detecting a node going down) means that we have at least five
seconds after a node goes down before etcd notices the lease expiring,
and a few milliseconds more or less won't matter.

But we have tests that assume either that node 0 is always the
coordinator (wrong) or that waiting for node 0 to think the cluster
is up means that every node in the cluster thinks the cluster is up,
or at least that it means that the coordinator thinks the cluster is
up. We retried later operations but not the initial ones against
the coordinator.

In fact, we probably want to wait for the entire cluster to think
it's up before we start trying things on clusters.

We also replace the "CheckClusterState" function with the existing
AwaitState call, or a new AssertState which errors out since that's
the way we usually use AwaitState anyway.

In the AwaitPrimaryState function, which used to be
AwaitCoordinatorState in a different long-lost revision, we have
to delay until a primary node is available, or fail if one does
not become available, to avoid a panic. This probably shouldn't
happen anymore, because of the last change:

Also, rovide dummy topology.Node entries before metadata is read.

During initial startup, we want to be able to do things like determine
which node is the primary, even before we've read metadata from them.

To do this, we populate the node list with dummy entries that just have
the ID (the only part we need to sort our list), and a node state of
UNKNOWN.

This breaks the fancy logic for determining whether or not to update
the node data, because the initial status of UNKNOWN matches what we
get from SetMetadata giving us new data so we end up not realizing
that this was actually a meaningful change. But actually, that's
a pretty niche optimization; we usually only get state changes when
there's an actual change in state. The updates here are cheap
and only happen after a write (or on the first query) so it's not
worth making the logic a lot fancier to make it work, when we can
just do the simple thing and update any time the dirty flag is set.

We also standardize on a 50ms delay, because 1ms delays were
really expensive when each check was hitting etcd multiple times,
and 50ms is Usually Long Enough.
2021-04-13 12:37:07 -05:00

600 lines
18 KiB
Go

// Copyright 2017 Pilosa Corp.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package test
import (
"context"
"fmt"
"math"
"sort"
"strings"
"testing"
"time"
"github.com/pilosa/pilosa/v2"
"github.com/pilosa/pilosa/v2/api/client"
"github.com/pilosa/pilosa/v2/disco"
"github.com/pilosa/pilosa/v2/logger"
"github.com/pilosa/pilosa/v2/proto"
"github.com/pilosa/pilosa/v2/server"
"github.com/pilosa/pilosa/v2/storage"
"github.com/pkg/errors"
"golang.org/x/sync/errgroup"
)
// modHasher represents a simple, mod-based hashing.
type ModHasher struct{}
func (*ModHasher) Hash(key uint64, n int) int { return int(key) % n }
func (*ModHasher) Name() string { return "mod" }
// Cluster represents a Pilosa cluster (multiple Command instances)
type Cluster struct {
Nodes []*Command
tb testing.TB
}
// Query executes an API.Query through one of the cluster's node's API. It fails
// the test if there is an error.
func (c *Cluster) Query(t testing.TB, index, query string) pilosa.QueryResponse {
t.Helper()
if len(c.Nodes) == 0 {
t.Fatal("must have at least one node in cluster to query")
}
return c.GetPrimary().QueryAPI(t, &pilosa.QueryRequest{Index: index, Query: query})
}
// QueryHTTP executes a PQL query through the HTTP endpoint. It fails
// the test for explicit errors, but returns an error which has the
// response body if the HTTP call returns a non-OK status.
func (c *Cluster) QueryHTTP(t testing.TB, index, query string) (string, error) {
t.Helper()
if len(c.Nodes) == 0 {
t.Fatal("must have at least one node in cluster to query")
}
return c.GetPrimary().Query(t, index, "", query)
}
// QueryGRPC executes a PQL query through the GRPC endpoint. It fails the
// test if there is an error.
func (c *Cluster) QueryGRPC(t testing.TB, index, query string) *proto.TableResponse {
t.Helper()
if len(c.Nodes) == 0 {
t.Fatal("must have at least one node in cluster to query")
}
grpcClient, err := client.NewGRPCClient([]string{fmt.Sprintf("%s:%d", c.GetPrimary().Server.GRPCURI().Host, c.GetPrimary().Server.GRPCURI().Port)}, nil, logger.NopLogger)
if err != nil {
t.Fatalf("getting GRPC client: %v", err)
}
defer grpcClient.Close()
tableResp, err := grpcClient.QueryUnary(context.Background(), index, query)
if err != nil {
t.Fatalf("querying unary: %v", err)
}
return tableResp
}
// GetIdleNode gets the node at the given index. This method is used (instead of
// `GetNode()`) when the cluster has yet to be started. In that case, etcd has
// not assigned each node an ID, and therefore the nodes are not in their final,
// sorted order. In other words, this method can only be used to retrieve a node
// when order doesn't matter. An example is if you need to do something like
// this:
// c.GetNode(0).Config.Cluster.ReplicaN = 2
// c.GetNode(1).Config.Cluster.ReplicaN = 2
// In this example, the test needs the replication factor to be set to 2 before
// starting; it's ok to reference each node by its index in the pre-sorted node
// list. It's also safe to use this method after `MustRunCluster()` if the
// cluster contains only one node.
func (c *Cluster) GetIdleNode(n int) *Command {
return c.Nodes[n]
}
// GetNode gets the node at the given index; this method assumes the cluster has
// already been started. Because the node IDs are assigned randomly, they can be
// in an order that does not align with the test's expectations. For example, a
// test might create a 3-node cluster and retrieve them using `GetNode(0)`,
// `GetNode(1)`, and `GetNode(2)` respectively. But if the node IDs are `456`,
// `123`, `789`, then we actually want `GetNode(0)` to return `c.Nodes[1]`, and
// `GetNode(1)` to return `c.Nodes[0]`. This method looks at all the node IDs,
// sorts them, and then returns the node that the test expects.
func (c *Cluster) GetNode(n int) *Command {
// Put all the node IDs into a list to be sorted.
ids := make([]nodePlace, len(c.Nodes))
for i := range c.Nodes {
ids[i].id = c.Nodes[i].ID()
ids[i].idx = i
}
// Sort the list.
sort.SliceStable(ids, func(i, j int) bool {
return ids[i].id < ids[j].id
})
// Return the node which is at the given position in the sorted list.
return c.Nodes[ids[n].idx]
}
// GetPrimary gets the node which has been determined to be the primary.
// This used to be node0 in tests, but since implementing etcd, the primary
// can be any node in the cluster, so we have to use this method in tests which
// need to act on the primary.
func (c *Cluster) GetPrimary() *Command {
for _, n := range c.Nodes {
if n.IsPrimary() {
return n
}
}
return nil
}
// GetNonPrimary gets first first non-primary node in the list of nodes.
func (c *Cluster) GetNonPrimary() *Command {
for _, n := range c.Nodes {
if !n.IsPrimary() {
return n
}
}
return nil
}
// GetNonPrimaries gets all nodes except the primary.
func (c *Cluster) GetNonPrimaries() []*Command {
rtn := make([]*Command, 0)
for _, n := range c.Nodes {
if !n.IsPrimary() {
rtn = append(rtn, n)
}
}
return rtn
}
// nodePlace represents a node's ID and its index into the c.Nodes slice.
type nodePlace struct {
id string
idx int
}
func (c *Cluster) GetHolder(n int) *Holder {
return &Holder{Holder: c.GetNode(n).Server.Holder()}
}
func (c *Cluster) Len() int {
return len(c.Nodes)
}
func (c *Cluster) ImportBitsWithTimestamp(t testing.TB, index, field string, rowcols [][2]uint64, timestamps []int64) {
t.Helper()
byShard := make(map[uint64][][2]uint64)
byShardTs := make(map[uint64][]int64)
for i, rowcol := range rowcols {
shard := rowcol[1] / pilosa.ShardWidth
byShard[shard] = append(byShard[shard], rowcol)
if len(timestamps) > 0 {
byShardTs[shard] = append(byShardTs[shard], timestamps[i])
}
}
for shard, bits := range byShard {
rowIDs := make([]uint64, len(bits))
colIDs := make([]uint64, len(bits))
for i, bit := range bits {
rowIDs[i] = bit[0]
colIDs[i] = bit[1]
}
nodes, err := c.GetPrimary().API.ShardNodes(context.Background(), index, shard)
if err != nil {
t.Fatalf("getting shard nodes: %v", err)
}
// TODO won't be necessary to do all nodes once that works hits
// (travis) this TODO is not clear to me, but I think it's
// suggesting that elsewhere we would support importing to a
// single node, regardless of where the data ends up.
for _, node := range nodes {
for _, com := range c.Nodes {
if com.API.Node().ID != node.ID {
continue
}
if len(timestamps) == 0 {
err := com.API.Import(context.Background(), nil, &pilosa.ImportRequest{
Index: index,
Field: field,
Shard: shard,
RowIDs: rowIDs,
ColumnIDs: colIDs,
})
if err != nil {
t.Fatalf("importing data: %v", err)
}
} else {
ts := byShardTs[shard]
err := com.API.Import(context.Background(), nil, &pilosa.ImportRequest{
Index: index,
Field: field,
Shard: shard,
RowIDs: rowIDs,
ColumnIDs: colIDs,
Timestamps: ts,
})
if err != nil {
t.Fatalf("importing data: %v", err)
}
}
}
}
}
}
func (c *Cluster) ImportBits(t testing.TB, index, field string, rowcols [][2]uint64) {
var noTime []int64
c.ImportBitsWithTimestamp(t, index, field, rowcols, noTime)
}
// ImportKeyKey imports data into an index where both the index and
// the field are using string keys.
func (c *Cluster) ImportKeyKey(t testing.TB, index, field string, valAndRecKeys [][2]string) {
t.Helper()
importRequest := &pilosa.ImportRequest{
Index: index,
Field: field,
RowKeys: make([]string, len(valAndRecKeys)),
ColumnKeys: make([]string, len(valAndRecKeys)),
}
for i, vk := range valAndRecKeys {
importRequest.RowKeys[i] = vk[0]
importRequest.ColumnKeys[i] = vk[1]
}
err := c.GetPrimary().API.Import(context.Background(), nil, importRequest)
if err != nil {
t.Fatalf("importing keykey data: %v", err)
}
}
// TimeQuantumKey is a string key and a string+key value
type TimeQuantumKey struct {
RowKey string
ColKey string
Ts int64
}
// ImportTimeQuantumKey imports data into an index where the index is keyd
// and the field is a time-quantum
func (c *Cluster) ImportTimeQuantumKey(t testing.TB, index, field string, entries []TimeQuantumKey) {
t.Helper()
importRequest := &pilosa.ImportRequest{
Index: index,
Field: field,
RowKeys: make([]string, len(entries)),
ColumnKeys: make([]string, len(entries)),
Timestamps: make([]int64, len(entries)),
}
for i, entry := range entries {
importRequest.ColumnKeys[i] = entry.ColKey
importRequest.RowKeys[i] = entry.RowKey
importRequest.Timestamps[i] = entry.Ts
}
err := c.GetPrimary().API.Import(context.Background(), nil, importRequest)
if err != nil {
t.Fatalf("importing keykey data: %v", err)
}
}
// IntKey is a string key and a signed integer value.
type IntKey struct {
Val int64
Key string
}
// ImportIntKey imports int data into an index which uses string keys.
func (c *Cluster) ImportIntKey(t testing.TB, index, field string, pairs []IntKey) {
t.Helper()
importRequest := &pilosa.ImportValueRequest{
Index: index,
Field: field,
Shard: math.MaxUint64,
ColumnKeys: make([]string, len(pairs)),
Values: make([]int64, len(pairs)),
}
for i, pair := range pairs {
importRequest.Values[i] = pair.Val
importRequest.ColumnKeys[i] = pair.Key
}
if err := c.GetPrimary().API.ImportValue(context.Background(), nil, importRequest); err != nil {
t.Fatalf("importing IntKey data: %v", err)
}
}
type IntID struct {
Val int64
ID uint64
}
// ImportIntID imports data into an int field in an unkeyed index.
func (c *Cluster) ImportIntID(t testing.TB, index, field string, pairs []IntID) {
t.Helper()
importRequest := &pilosa.ImportValueRequest{
Index: index,
Field: field,
Shard: math.MaxUint64,
ColumnIDs: make([]uint64, len(pairs)),
Values: make([]int64, len(pairs)),
}
for i, pair := range pairs {
importRequest.Values[i] = pair.Val
importRequest.ColumnIDs[i] = pair.ID
}
if err := c.GetPrimary().API.ImportValue(context.Background(), nil, importRequest); err != nil {
t.Fatalf("importing IntID data: %v", err)
}
}
// KeyID represents a key and an ID for importing data into an index
// and field where one uses string keys and the other does not.
type KeyID struct {
Key string
ID uint64
}
//ImportIDKey imports data into an unkeyed set field in a keyed index.
func (c *Cluster) ImportIDKey(t testing.TB, index, field string, pairs []KeyID) {
t.Helper()
importRequest := &pilosa.ImportRequest{
Index: index,
Field: field,
RowIDs: make([]uint64, len(pairs)),
ColumnKeys: make([]string, len(pairs)),
}
for i, pair := range pairs {
importRequest.RowIDs[i] = pair.ID
importRequest.ColumnKeys[i] = pair.Key
}
err := c.GetPrimary().API.Import(context.Background(), nil, importRequest)
if err != nil {
t.Fatalf("importing IDKey data: %v", err)
}
}
// CreateField creates the index (if necessary) and field specified.
func (c *Cluster) CreateField(t testing.TB, index string, iopts pilosa.IndexOptions, field string, fopts ...pilosa.FieldOption) *pilosa.Field {
t.Helper()
idx, err := c.GetPrimary().API.CreateIndex(context.Background(), index, iopts)
if err != nil && !strings.Contains(err.Error(), "index already exists") {
t.Fatalf("creating index: %v", err)
} else if err != nil { // index exists
idx, err = c.GetPrimary().API.Index(context.Background(), index)
if err != nil {
t.Fatalf("getting index: %v", err)
}
}
if idx.Options() != iopts {
t.Logf("existing index options:\n%v\ndon't match given opts:\n%v\n in pilosa/test.Cluster.CreateField", idx.Options(), iopts)
}
f, err := c.GetPrimary().API.CreateField(context.Background(), index, field, fopts...)
// we'll assume the field doesn't exist because checking if the options
// match seems painful.
if err != nil {
t.Fatalf("creating field: %v", err)
}
return f
}
// Start runs a Cluster
func (c *Cluster) Start() error {
err := GetPortsGenConfigs(c.tb, c.Nodes)
if err != nil {
return errors.Wrap(err, "configuring cluster ports")
}
var eg errgroup.Group
for _, cc := range c.Nodes {
cc := cc
eg.Go(func() error {
return cc.Start()
})
}
err = eg.Wait()
if err != nil {
return errors.Wrap(err, "starting cluster")
}
return c.AwaitState(disco.ClusterStateNormal, 30*time.Second)
}
// Close stops a Cluster
func (c *Cluster) Close() error {
for i, cc := range c.Nodes {
if err := cc.Close(); err != nil {
return errors.Wrapf(err, "stopping server %d", i)
}
}
return nil
}
func (c *Cluster) CloseAndRemoveNonPrimary() error {
for i, n := range c.Nodes {
if !n.IsPrimary() {
return c.CloseAndRemove(i)
}
}
return errors.New("could not find non-primary node")
}
func (c *Cluster) CloseAndRemove(n int) error {
if n < 0 || n >= len(c.Nodes) {
return fmt.Errorf("close/remove from cluster: index %d out of range (len %d)", n, len(c.Nodes))
}
err := c.Nodes[n].Close()
copy(c.Nodes[n:], c.Nodes[n+1:])
c.Nodes = c.Nodes[:len(c.Nodes)-1]
return err
}
// AwaitPrimaryState waits for the cluster primary to reach a specified cluster state.
// When this happens, we know etcd reached a combination of node states that
// would imply this cluster state, but some nodes may not have caught up yet;
// we just test that the coordinator thought the cluster was in the given state.
func (c *Cluster) AwaitPrimaryState(expectedState disco.ClusterState, timeout time.Duration) error {
if len(c.Nodes) < 1 {
return errors.New("can't await coordinator state on an empty cluster")
}
primary := c.GetPrimary()
if primary == nil {
startTime := time.Now()
var elapsed time.Duration
for elapsed = 0; elapsed <= timeout; elapsed = time.Since(startTime) {
time.Sleep(50 * time.Millisecond)
primary = c.GetPrimary()
if primary != nil {
break
}
}
if primary == nil {
return errors.New("timed out waiting for cluster to have valid topology")
}
// we used up some of our timeout waiting for this
c.tb.Logf("had to wait %v for cluster topology", elapsed)
timeout -= elapsed
}
onlyCoordinator := &Cluster{Nodes: []*Command{primary}}
return onlyCoordinator.AwaitState(expectedState, timeout)
}
// ExceptionalState returns an error if any node in the cluster is not
// in the expected state.
func (c *Cluster) ExceptionalState(expectedState disco.ClusterState) error {
for _, node := range c.Nodes {
state, err := node.API.State()
if err != nil || state != expectedState {
return fmt.Errorf("node %q: state %s: err %v", node.ID(), state, err)
}
}
return nil
}
// AwaitState waits for the whole cluster to reach a specified state.
func (c *Cluster) AwaitState(expectedState disco.ClusterState, timeout time.Duration) (err error) {
if len(c.Nodes) < 1 {
return errors.New("can't await state of an empty cluster")
}
startTime := time.Now()
var elapsed time.Duration
for elapsed = 0; elapsed <= timeout; elapsed = time.Since(startTime) {
// Counterintuitive: We're returning if the err *is* nil,
// meaning we've reached the expected state.
if err = c.ExceptionalState(expectedState); err == nil {
return err
}
time.Sleep(50 * time.Millisecond)
}
return fmt.Errorf("waited %v for cluster to reach state %q: %v",
elapsed, expectedState, err)
}
// MustNewCluster creates a new cluster. If opts contains only one
// slice of command options, those options are used with every node.
// If it is empty, default options are used. Otherwise, it must contain size
// slices of command options, which are used with corresponding nodes.
func MustNewCluster(tb testing.TB, size int, opts ...[]server.CommandOption) *Cluster {
tb.Helper()
// We want tests to default to using the in-memory translate store, so we
// prepend opts with that functional option. If a different translate store
// has been specified, it will override this one.
opts = prependOpts(opts, size)
c, err := newCluster(tb, size, opts...)
if err != nil {
tb.Fatalf("new cluster: %v", err)
}
return c
}
// newCluster creates a new cluster
func newCluster(tb testing.TB, size int, opts ...[]server.CommandOption) (*Cluster, error) {
if size == 0 {
return nil, errors.New("cluster must contain at least one node")
}
if len(opts) != size && len(opts) != 0 && len(opts) != 1 {
return nil, errors.New("Slice of CommandOptions must be of length 0, 1, or equal to the number of cluster nodes")
}
cluster := &Cluster{Nodes: make([]*Command, size), tb: tb}
for i := 0; i < size; i++ {
var commandOpts []server.CommandOption
if len(opts) > 0 {
commandOpts = opts[i%len(opts)]
}
m := NewCommandNode(tb, commandOpts...)
m.Config.ImportWorkerPoolSize = 2
cluster.Nodes[i] = m
}
return cluster, nil
}
// MustRunCluster creates and starts a new cluster. The opts parameter
// is slightly magical; see MustNewCluster.
func MustRunCluster(tb testing.TB, size int, opts ...[]server.CommandOption) *Cluster {
cluster := MustNewCluster(tb, size, opts...)
err := cluster.Start()
if err != nil {
tb.Fatalf("run cluster: %v", err)
}
return cluster
}
// prependOpts applies prependTestServerOpts to each of the ops (one per
// node, or one for the entire cluser).
func prependOpts(opts [][]server.CommandOption, size int) [][]server.CommandOption {
if len(opts) == 0 {
opts = make([][]server.CommandOption, size)
for i := 0; i < size; i++ {
opts[i] = prependTestServerOpts([]server.CommandOption{})
}
} else if len(opts) == 1 {
opts2 := make([][]server.CommandOption, size)
for i := 0; i < size; i++ {
opts2[i] = prependTestServerOpts(opts[0])
}
return opts2
} else {
for i := range opts {
opts[i] = prependTestServerOpts(opts[i])
}
}
return opts
}
// prependTestServerOpts prepends opts with the OpenInMemTranslateStore.
func prependTestServerOpts(opts []server.CommandOption) []server.CommandOption {
defaultOpts := []server.CommandOption{
server.OptCommandServerOptions(
pilosa.OptServerOpenTranslateStore(pilosa.OpenInMemTranslateStore),
pilosa.OptServerNodeDownRetries(5, 100*time.Millisecond),
pilosa.OptServerStorageConfig(&storage.Config{
Backend: pilosa.CurrentBackendOrDefault(),
FsyncEnabled: true,
}),
),
}
return append(defaultOpts, opts...)
}