open-consul/api/semaphore_test.go

545 lines
11 KiB
Go

package api
import (
"log"
"net/http"
"net/http/httptest"
"net/http/httputil"
"strings"
"sync"
"testing"
"time"
)
func createTestSemaphore(t *testing.T, c *Client, prefix string, limit int) (*Semaphore, *Session) {
t.Helper()
session := c.Session()
se := &SessionEntry{
Name: DefaultSemaphoreSessionName,
TTL: DefaultSemaphoreSessionTTL,
Behavior: SessionBehaviorDelete,
}
id, _, err := session.CreateNoChecks(se, nil)
if err != nil {
t.Fatalf("err: %v", err)
}
opts := &SemaphoreOptions{
Prefix: prefix,
Limit: limit,
Session: id,
SessionName: se.Name,
SessionTTL: se.TTL,
}
sema, err := c.SemaphoreOpts(opts)
if err != nil {
t.Fatalf("err: %v", err)
}
return sema, session
}
func TestAPI_SemaphoreAcquireRelease(t *testing.T) {
t.Parallel()
c, s := makeClient(t)
defer s.Stop()
sema, session := createTestSemaphore(t, c, "test/semaphore", 2)
defer session.Destroy(sema.opts.Session, nil)
// Initial release should fail
err := sema.Release()
if err != ErrSemaphoreNotHeld {
t.Fatalf("err: %v", err)
}
// Should work
lockCh, err := sema.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if lockCh == nil {
t.Fatalf("not hold")
}
// Double lock should fail
_, err = sema.Acquire(nil)
if err != ErrSemaphoreHeld {
t.Fatalf("err: %v", err)
}
// Should be held
select {
case <-lockCh:
t.Fatalf("should be held")
default:
}
// Initial release should work
err = sema.Release()
if err != nil {
t.Fatalf("err: %v", err)
}
// Double unlock should fail
err = sema.Release()
if err != ErrSemaphoreNotHeld {
t.Fatalf("err: %v", err)
}
// Should lose resource
select {
case <-lockCh:
case <-time.After(time.Second):
t.Fatalf("should not be held")
}
}
func TestAPI_SemaphoreForceInvalidate(t *testing.T) {
t.Parallel()
c, s := makeClient(t)
defer s.Stop()
s.WaitForSerfCheck(t)
sema, session := createTestSemaphore(t, c, "test/semaphore", 2)
defer session.Destroy(sema.opts.Session, nil)
// Should work
lockCh, err := sema.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if lockCh == nil {
t.Fatalf("not acquired")
}
defer sema.Release()
go func() {
// Nuke the session, simulator an operator invalidation
// or a health check failure
session := c.Session()
session.Destroy(sema.lockSession, nil)
}()
// Should loose slot
select {
case <-lockCh:
case <-time.After(time.Second):
t.Fatalf("should not be locked")
}
}
func TestAPI_SemaphoreDeleteKey(t *testing.T) {
t.Parallel()
c, s := makeClient(t)
defer s.Stop()
s.WaitForSerfCheck(t)
sema, session := createTestSemaphore(t, c, "test/semaphore", 2)
defer session.Destroy(sema.opts.Session, nil)
// Should work
lockCh, err := sema.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if lockCh == nil {
t.Fatalf("not locked")
}
defer sema.Release()
go func() {
// Nuke the key, simulate an operator intervention
kv := c.KV()
kv.DeleteTree("test/semaphore", nil)
}()
// Should loose leadership
select {
case <-lockCh:
case <-time.After(time.Second):
t.Fatalf("should not be locked")
}
}
func TestAPI_SemaphoreContend(t *testing.T) {
t.Parallel()
c, s := makeClient(t)
defer s.Stop()
s.WaitForSerfCheck(t)
wg := &sync.WaitGroup{}
acquired := make([]bool, 4)
for idx := range acquired {
wg.Add(1)
go func(idx int) {
defer wg.Done()
sema, session := createTestSemaphore(t, c, "test/semaphore", 2)
defer session.Destroy(sema.opts.Session, nil)
// Should work eventually, will contend
lockCh, err := sema.Acquire(nil)
if err != nil {
t.Errorf("err: %v", err)
return
}
if lockCh == nil {
t.Errorf("not locked")
return
}
defer sema.Release()
log.Printf("Contender %d acquired", idx)
// Set acquired and then leave
acquired[idx] = true
}(idx)
}
// Wait for termination
doneCh := make(chan struct{})
go func() {
wg.Wait()
close(doneCh)
}()
// Wait for everybody to get a turn
select {
case <-doneCh:
case <-time.After(3 * DefaultLockRetryTime):
t.Fatalf("timeout")
}
for idx, did := range acquired {
if !did {
t.Fatalf("contender %d never acquired", idx)
}
}
}
func TestAPI_SemaphoreBadLimit(t *testing.T) {
t.Parallel()
c, s := makeClient(t)
defer s.Stop()
s.WaitForSerfCheck(t)
_, err := c.SemaphorePrefix("test/semaphore", 0)
if err == nil {
t.Fatalf("should error, limit must be positive")
}
sema, session := createTestSemaphore(t, c, "test/semaphore", 1)
defer session.Destroy(sema.opts.Session, nil)
_, err = sema.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
sema2, session := createTestSemaphore(t, c, "test/semaphore", 2)
defer session.Destroy(sema.opts.Session, nil)
_, err = sema2.Acquire(nil)
if err.Error() != "semaphore limit conflict (lock: 1, local: 2)" {
t.Fatalf("err: %v", err)
}
}
func TestAPI_SemaphoreDestroy(t *testing.T) {
t.Parallel()
c, s := makeClient(t)
defer s.Stop()
s.WaitForSerfCheck(t)
sema, session := createTestSemaphore(t, c, "test/semaphore", 2)
defer session.Destroy(sema.opts.Session, nil)
sema2, session := createTestSemaphore(t, c, "test/semaphore", 2)
defer session.Destroy(sema.opts.Session, nil)
_, err := sema.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
_, err = sema2.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
// Destroy should fail, still held
if err := sema.Destroy(); err != ErrSemaphoreHeld {
t.Fatalf("err: %v", err)
}
err = sema.Release()
if err != nil {
t.Fatalf("err: %v", err)
}
// Destroy should fail, still in use
if err := sema.Destroy(); err != ErrSemaphoreInUse {
t.Fatalf("err: %v", err)
}
err = sema2.Release()
if err != nil {
t.Fatalf("err: %v", err)
}
// Destroy should work
if err := sema.Destroy(); err != nil {
t.Fatalf("err: %v", err)
}
// Destroy should work
if err := sema2.Destroy(); err != nil {
t.Fatalf("err: %v", err)
}
}
func TestAPI_SemaphoreConflict(t *testing.T) {
t.Parallel()
c, s := makeClient(t)
defer s.Stop()
s.WaitForSerfCheck(t)
lock, session := createTestLock(t, c, "test/sema/.lock")
defer session.Destroy(lock.opts.Session, nil)
// Should work
leaderCh, err := lock.Lock(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if leaderCh == nil {
t.Fatalf("not leader")
}
defer lock.Unlock()
sema, session := createTestSemaphore(t, c, "test/sema/", 2)
defer session.Destroy(sema.opts.Session, nil)
// Should conflict with lock
_, err = sema.Acquire(nil)
if err != ErrSemaphoreConflict {
t.Fatalf("err: %v", err)
}
// Should conflict with lock
err = sema.Destroy()
if err != ErrSemaphoreConflict {
t.Fatalf("err: %v", err)
}
}
func TestAPI_SemaphoreMonitorRetry(t *testing.T) {
t.Parallel()
raw, s := makeClient(t)
defer s.Stop()
s.WaitForSerfCheck(t)
// Set up a server that always responds with 500 errors.
failer := func(w http.ResponseWriter, req *http.Request) {
w.WriteHeader(500)
}
outage := httptest.NewServer(http.HandlerFunc(failer))
defer outage.Close()
// Set up a reverse proxy that will send some requests to the
// 500 server and pass everything else through to the real Consul
// server.
var mutex sync.Mutex
errors := 0
director := func(req *http.Request) {
mutex.Lock()
defer mutex.Unlock()
req.URL.Scheme = "http"
if errors > 0 && req.Method == "GET" && strings.Contains(req.URL.Path, "/v1/kv/test/sema/.lock") {
req.URL.Host = outage.URL[7:] // Strip off "http://".
errors--
} else {
req.URL.Host = raw.config.Address
}
}
proxy := httptest.NewServer(&httputil.ReverseProxy{Director: director})
defer proxy.Close()
// Make another client that points at the proxy instead of the real
// Consul server.
config := raw.config
config.Address = proxy.URL[7:] // Strip off "http://".
c, err := NewClient(&config)
if err != nil {
t.Fatalf("err: %v", err)
}
// Set up a lock with retries enabled.
opts := &SemaphoreOptions{
Prefix: "test/sema/.lock",
Limit: 2,
SessionTTL: "60s",
MonitorRetries: 3,
}
sema, err := c.SemaphoreOpts(opts)
if err != nil {
t.Fatalf("err: %v", err)
}
// Make sure the default got set.
if sema.opts.MonitorRetryTime != DefaultMonitorRetryTime {
t.Fatalf("bad: %d", sema.opts.MonitorRetryTime)
}
// Now set a custom time for the test.
opts.MonitorRetryTime = 250 * time.Millisecond
sema, err = c.SemaphoreOpts(opts)
if err != nil {
t.Fatalf("err: %v", err)
}
if sema.opts.MonitorRetryTime != 250*time.Millisecond {
t.Fatalf("bad: %d", sema.opts.MonitorRetryTime)
}
// Should get the lock.
ch, err := sema.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if ch == nil {
t.Fatalf("didn't acquire")
}
// Take the semaphore using the raw client to force the monitor to wake
// up and check the lock again. This time we will return errors for some
// of the responses.
mutex.Lock()
errors = 2
mutex.Unlock()
another, err := raw.SemaphoreOpts(opts)
if err != nil {
t.Fatalf("err: %v", err)
}
if _, err := another.Acquire(nil); err != nil {
t.Fatalf("err: %v", err)
}
time.Sleep(5 * opts.MonitorRetryTime)
// Should still have the semaphore.
select {
case <-ch:
t.Fatalf("lost the semaphore")
default:
}
// Now return an overwhelming number of errors, using the raw client to
// poke the key and get the monitor to run again.
mutex.Lock()
errors = 10
mutex.Unlock()
if err := another.Release(); err != nil {
t.Fatalf("err: %v", err)
}
time.Sleep(5 * opts.MonitorRetryTime)
// Should lose the semaphore.
select {
case <-ch:
case <-time.After(time.Second):
t.Fatalf("should not have the semaphore")
}
}
func TestAPI_SemaphoreOneShot(t *testing.T) {
t.Parallel()
c, s := makeClient(t)
defer s.Stop()
s.WaitForSerfCheck(t)
// Set up a semaphore as a one-shot.
opts := &SemaphoreOptions{
Prefix: "test/sema/.lock",
Limit: 2,
SemaphoreTryOnce: true,
}
sema, err := c.SemaphoreOpts(opts)
if err != nil {
t.Fatalf("err: %v", err)
}
// Make sure the default got set.
if sema.opts.SemaphoreWaitTime != DefaultSemaphoreWaitTime {
t.Fatalf("bad: %d", sema.opts.SemaphoreWaitTime)
}
// Now set a custom time for the test.
opts.SemaphoreWaitTime = 250 * time.Millisecond
sema, err = c.SemaphoreOpts(opts)
if err != nil {
t.Fatalf("err: %v", err)
}
if sema.opts.SemaphoreWaitTime != 250*time.Millisecond {
t.Fatalf("bad: %d", sema.opts.SemaphoreWaitTime)
}
// Should acquire the semaphore.
ch, err := sema.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if ch == nil {
t.Fatalf("should have acquired the semaphore")
}
// Try with another session.
another, err := c.SemaphoreOpts(opts)
if err != nil {
t.Fatalf("err: %v", err)
}
ch, err = another.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if ch == nil {
t.Fatalf("should have acquired the semaphore")
}
// Try with a third one that shouldn't get it.
contender, err := c.SemaphoreOpts(opts)
if err != nil {
t.Fatalf("err: %v", err)
}
start := time.Now()
ch, err = contender.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if ch != nil {
t.Fatalf("should not have acquired the semaphore")
}
diff := time.Since(start)
if diff < contender.opts.SemaphoreWaitTime {
t.Fatalf("time out of bounds: %9.6f", diff.Seconds())
}
// Give up a slot and make sure the third one can get it.
if err := another.Release(); err != nil {
t.Fatalf("err: %v", err)
}
ch, err = contender.Acquire(nil)
if err != nil {
t.Fatalf("err: %v", err)
}
if ch == nil {
t.Fatalf("should have acquired the semaphore")
}
}