consul/agent/blockingquery/blockingquery_test.go

341 lines
11 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package blockingquery
import (
"fmt"
"github.com/hashicorp/consul/agent/consul/state"
"github.com/hashicorp/go-memdb"
"github.com/stretchr/testify/mock"
"github.com/stretchr/testify/require"
"testing"
"time"
)
func TestServer_blockingQuery(t *testing.T) {
t.Parallel()
getFSM := func(t *testing.T, additionalCfgFunc func(mockFSM *MockFSMServer)) *MockFSMServer {
fsm := NewMockFSMServer(t)
testCh := make(chan struct{})
tombstoneGC, err := state.NewTombstoneGC(time.Second, time.Second)
require.NoError(t, err)
store := state.NewStateStore(tombstoneGC)
fsm.On("GetShutdownChannel").Return(testCh)
fsm.On("GetState").Return(store)
fsm.On("SetQueryMeta", mock.Anything, mock.Anything).Return(nil)
if additionalCfgFunc != nil {
additionalCfgFunc(fsm)
}
return fsm
}
getOpts := func(t *testing.T, additionalCfgFunc func(options *MockRequestOptions)) *MockRequestOptions {
requestOpts := NewMockRequestOptions(t)
requestOpts.On("GetRequireConsistent").Return(false)
requestOpts.On("GetToken").Return("fake-token")
if additionalCfgFunc != nil {
additionalCfgFunc(requestOpts)
}
return requestOpts
}
getMeta := func(t *testing.T, additionalCfgFunc func(mockMeta *MockResponseMeta)) *MockResponseMeta {
meta := NewMockResponseMeta(t)
if additionalCfgFunc != nil {
additionalCfgFunc(meta)
}
return meta
}
// Perform a non-blocking query. Note that it's significant that the meta has
// a zero index in response - the implied opts.MinQueryIndex is also zero but
// this should not block still.
t.Run("non-blocking query", func(t *testing.T) {
var calls int
fn := func(_ memdb.WatchSet, _ *state.Store) error {
calls++
return nil
}
err := Query(getFSM(t, nil), getOpts(t, func(mockOpts *MockRequestOptions) {
mockOpts.On("GetMinQueryIndex").Return(uint64(0))
}), getMeta(t, nil), fn)
require.NoError(t, err)
require.Equal(t, 1, calls)
})
// Perform a blocking query that gets woken up and loops around once.
t.Run("blocking query - single loop", func(t *testing.T) {
opts := getOpts(t, func(options *MockRequestOptions) {
options.On("GetMinQueryIndex").Return(uint64(1))
options.On("GetMaxQueryTime").Return(1*time.Second, nil)
})
meta := getMeta(t, func(mockMeta *MockResponseMeta) {
mockMeta.On("GetIndex").Return(uint64(1))
})
fsm := getFSM(t, func(mockFSM *MockFSMServer) {
mockFSM.On("RPCQueryTimeout", mock.Anything).Return(1 * time.Second)
mockFSM.On("IncrementBlockingQueries").Return(uint64(1))
mockFSM.On("DecrementBlockingQueries").Return(uint64(1))
})
var calls int
fn := func(ws memdb.WatchSet, _ *state.Store) error {
if calls == 0 {
meta.On("GetIndex").Return(uint64(3))
fakeCh := make(chan struct{})
close(fakeCh)
ws.Add(fakeCh)
} else {
meta.On("GetIndex").Return(uint64(4))
}
calls++
return nil
}
err := Query(fsm, opts, meta, fn)
require.NoError(t, err)
require.Equal(t, 2, calls)
})
// Perform a blocking query that returns a zero index from blocking func (e.g.
// no state yet). This should still return an empty response immediately, but
// with index of 1 and then block on the next attempt. In one sense zero index
// is not really a valid response from a state method that is not an error but
// in practice a lot of state store operations do return it unless they
// explicitly special checks to turn 0 into 1. Often this is not caught or
// covered by tests but eventually when hit in the wild causes blocking
// clients to busy loop and burn CPU. This test ensure that blockingQuery
// systematically does the right thing to prevent future bugs like that.
t.Run("blocking query with 0 modifyIndex from state func", func(t *testing.T) {
opts := getOpts(t, func(options *MockRequestOptions) {
options.On("GetMinQueryIndex").Return(uint64(0))
})
meta := getMeta(t, func(mockMeta *MockResponseMeta) {
mockMeta.On("GetIndex").Return(uint64(1))
})
fsm := getFSM(t, func(mockFSM *MockFSMServer) {
mockFSM.On("RPCQueryTimeout", mock.Anything).Return(1 * time.Second)
mockFSM.On("IncrementBlockingQueries").Return(uint64(1))
mockFSM.On("DecrementBlockingQueries").Return(uint64(1))
})
var calls int
fn := func(ws memdb.WatchSet, _ *state.Store) error {
if opts.GetMinQueryIndex() > 0 {
// If client requested blocking, block forever. This is simulating
// waiting for the watched resource to be initialized/written to giving
// it a non-zero index. Note the timeout on the query options is relied
// on to stop the test taking forever.
fakeCh := make(chan struct{})
ws.Add(fakeCh)
}
meta.On("GetIndex").Return(uint64(0))
calls++
return nil
}
err := Query(fsm, opts, meta, fn)
require.NoError(t, err)
require.Equal(t, 1, calls)
require.Equal(t, uint64(1), meta.GetIndex(),
"expect fake index of 1 to force client to block on next update")
// Simulate client making next request
opts = getOpts(t, func(options *MockRequestOptions) {
options.On("GetMinQueryIndex").Return(uint64(1))
options.On("GetMaxQueryTime").Return(20*time.Millisecond, nil)
})
// This time we should block even though the func returns index 0 still
t0 := time.Now()
require.NoError(t, Query(fsm, opts, meta, fn))
t1 := time.Now()
require.Equal(t, 2, calls)
require.Equal(t, uint64(1), meta.GetIndex(),
"expect fake index of 1 to force client to block on next update")
require.True(t, t1.Sub(t0) > 20*time.Millisecond,
"should have actually blocked waiting for timeout")
})
// Perform a query that blocks and gets interrupted when the state store
// is abandoned.
t.Run("blocking query interrupted by abandonCh", func(t *testing.T) {
opts := getOpts(t, func(options *MockRequestOptions) {
options.On("GetMinQueryIndex").Return(uint64(3))
options.On("GetMaxQueryTime").Return(20*time.Millisecond, nil)
})
meta := getMeta(t, func(mockMeta *MockResponseMeta) {
mockMeta.On("GetIndex").Return(uint64(1))
})
fsm := getFSM(t, func(mockFSM *MockFSMServer) {
mockFSM.On("RPCQueryTimeout", mock.Anything).Return(1 * time.Second)
mockFSM.On("IncrementBlockingQueries").Return(uint64(1))
mockFSM.On("DecrementBlockingQueries").Return(uint64(1))
})
var calls int
fn := func(_ memdb.WatchSet, _ *state.Store) error {
if calls == 0 {
meta.On("GetIndex").Return(uint64(1))
fsm.GetState().Abandon()
}
calls++
return nil
}
err := Query(fsm, opts, meta, fn)
require.NoError(t, err)
require.Equal(t, 1, calls)
})
t.Run("non-blocking query for item that does not exist", func(t *testing.T) {
opts := getOpts(t, func(options *MockRequestOptions) {
options.On("GetMinQueryIndex").Return(uint64(3))
options.On("GetMaxQueryTime").Return(20*time.Millisecond, nil)
})
meta := getMeta(t, func(mockMeta *MockResponseMeta) {
mockMeta.On("GetIndex").Return(uint64(1))
})
fsm := getFSM(t, func(mockFSM *MockFSMServer) {
mockFSM.On("RPCQueryTimeout", mock.Anything).Return(1 * time.Second)
mockFSM.On("IncrementBlockingQueries").Return(uint64(1))
mockFSM.On("DecrementBlockingQueries").Return(uint64(1))
})
calls := 0
fn := func(_ memdb.WatchSet, _ *state.Store) error {
calls++
return ErrNotFound
}
err := Query(fsm, opts, meta, fn)
require.NoError(t, err)
require.Equal(t, 1, calls)
})
t.Run("blocking query for item that does not exist", func(t *testing.T) {
opts := getOpts(t, func(options *MockRequestOptions) {
options.On("GetMinQueryIndex").Return(uint64(3))
options.On("GetMaxQueryTime").Return(100*time.Millisecond, nil)
})
meta := getMeta(t, func(mockMeta *MockResponseMeta) {
mockMeta.On("GetIndex").Return(uint64(1))
})
fsm := getFSM(t, func(mockFSM *MockFSMServer) {
mockFSM.On("RPCQueryTimeout", mock.Anything).Return(1 * time.Second)
mockFSM.On("IncrementBlockingQueries").Return(uint64(1))
mockFSM.On("DecrementBlockingQueries").Return(uint64(1))
})
calls := 0
fn := func(ws memdb.WatchSet, _ *state.Store) error {
calls++
if calls == 1 {
meta.On("GetIndex").Return(uint64(3))
ch := make(chan struct{})
close(ch)
ws.Add(ch)
return ErrNotFound
}
meta.On("GetIndex").Return(uint64(5))
return ErrNotFound
}
err := Query(fsm, opts, meta, fn)
require.NoError(t, err)
require.Equal(t, 2, calls)
})
t.Run("blocking query for item that existed and is removed", func(t *testing.T) {
opts := getOpts(t, func(options *MockRequestOptions) {
options.On("GetMinQueryIndex").Return(uint64(3))
// this query taks 1.002 sceonds locally so setting the timeout to 2 seconds
options.On("GetMaxQueryTime").Return(2*time.Second, nil)
})
meta := getMeta(t, func(mockMeta *MockResponseMeta) {
mockMeta.On("GetIndex").Return(uint64(3))
})
fsm := getFSM(t, func(mockFSM *MockFSMServer) {
mockFSM.On("RPCQueryTimeout", mock.Anything).Return(1 * time.Second)
mockFSM.On("IncrementBlockingQueries").Return(uint64(1))
mockFSM.On("DecrementBlockingQueries").Return(uint64(1))
})
calls := 0
fn := func(ws memdb.WatchSet, _ *state.Store) error {
calls++
if calls == 1 {
ch := make(chan struct{})
close(ch)
ws.Add(ch)
return nil
}
meta = getMeta(t, func(mockMeta *MockResponseMeta) {
meta.On("GetIndex").Return(uint64(5))
})
return ErrNotFound
}
start := time.Now()
require.NoError(t, Query(fsm, opts, meta, fn))
queryDuration := time.Since(start)
maxQueryDuration, err := opts.GetMaxQueryTime()
require.NoError(t, err)
require.True(t, queryDuration < maxQueryDuration, fmt.Sprintf("query timed out - queryDuration: %v, maxQueryDuration: %v", queryDuration, maxQueryDuration))
require.NoError(t, err)
require.Equal(t, 2, calls)
})
t.Run("blocking query for non-existent item that is created", func(t *testing.T) {
opts := getOpts(t, func(options *MockRequestOptions) {
options.On("GetMinQueryIndex").Return(uint64(3))
// this query taks 1.002 sceonds locally so setting the timeout to 2 seconds
options.On("GetMaxQueryTime").Return(2*time.Second, nil)
})
meta := getMeta(t, func(mockMeta *MockResponseMeta) {
mockMeta.On("GetIndex").Return(uint64(3))
})
fsm := getFSM(t, func(mockFSM *MockFSMServer) {
mockFSM.On("RPCQueryTimeout", mock.Anything).Return(1 * time.Second)
mockFSM.On("IncrementBlockingQueries").Return(uint64(1))
mockFSM.On("DecrementBlockingQueries").Return(uint64(1))
})
calls := 0
fn := func(ws memdb.WatchSet, _ *state.Store) error {
calls++
if calls == 1 {
ch := make(chan struct{})
close(ch)
ws.Add(ch)
return ErrNotFound
}
meta = getMeta(t, func(mockMeta *MockResponseMeta) {
meta.On("GetIndex").Return(uint64(5))
})
return nil
}
start := time.Now()
require.NoError(t, Query(fsm, opts, meta, fn))
queryDuration := time.Since(start)
maxQueryDuration, err := opts.GetMaxQueryTime()
require.NoError(t, err)
require.True(t, queryDuration < maxQueryDuration, fmt.Sprintf("query timed out - queryDuration: %v, maxQueryDuration: %v", queryDuration, maxQueryDuration))
require.NoError(t, err)
require.Equal(t, 2, calls)
})
}