Verified Commit 9dc0cb39 authored by onyinyang's avatar onyinyang 🔒
Browse files

Add more aggressive retry schedule for failed bridges

parent 5ef69d06

cache.go

+9 −3
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ type TestCache struct { 
	Entries map[string]*CacheEntry

	// entryTimeout determines how long a cache entry is valid for.

	entryTimeout      time.Duration

	errorEntryTimeout time.Duration

	l                 sync.Mutex

}
@@ -124,7 +125,12 @@ func (tc *TestCache) IsCached(bridgeLine string) *CacheEntry { 
	now := time.Now().UTC()

	tc.l.Lock()

	for index, entry := range (*tc).Entries {

		if entry.Time.Before(now.Add(-(*tc).entryTimeout)) {

		// If the test returned an error, shorten the time it is cached

		// to errorEntryTimeout (default 1 hour) so it can be tested again

		// more quickly. This aims to prevent bridges that are temporarily

		// down due to unfortunate test timing from being marked as `gone`

		// by rdsys

		if entry.Error != "" && entry.Time.Before(now.Add(-(*tc).errorEntryTimeout)) || entry.Time.Before(now.Add(-(*tc).entryTimeout)) {

			log.Printf("Deleting cache entry: %s", index)

			delete((*tc).Entries, index)

		}

cache_test.go

+26 −2
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ func init() { 
func NewCache() *TestCache {

	return &TestCache{

		Entries:           make(map[string]*CacheEntry),

		errorEntryTimeout: 1 * time.Hour,

		entryTimeout:      18 * time.Hour,

	}

}
@@ -57,6 +58,29 @@ func TestCacheFunctions(t *testing.T) { 
	if e != nil {

		t.Errorf("Got non-nil cache entry for bogus bridge line.")

	}



	// A failed bridge should only be cached for 1 hour.

	failedBridgeLine := "obfs4 127.0.0.1:1 cert=foo iat-mode=0"

	cache.AddEntry(failedBridgeLine, nil, time.Now().UTC().Add(-(time.Second * 6000)))

	e = cache.IsCached(failedBridgeLine)

	if e == nil {

		t.Errorf("Could not retrieve existing element from cache.")

	}

	testError = fmt.Errorf("bridge is restarting at an unfortunate time")

	// Manipulate entry time to be less than 5 seconds before the 1 hour mark

	// so we can check it is cached and removed from the cache within a

	// reasonable amount of time

	cache.AddEntry(failedBridgeLine, testError, time.Now().UTC().Add(-(time.Second * 3595)))

	e = cache.IsCached(failedBridgeLine)

	if e.Error != testError.Error() {

		t.Errorf("Got test result %q but expected %q.", e.Error, testError)

	}

	time.Sleep(6 * time.Second)

	e = cache.IsCached(failedBridgeLine)

	if e != nil {

		t.Errorf("Cache is empty but marks bridge line as existing.")

	}



}



func TestCacheFracFunctional(t *testing.T) {

main.go

+3 −1
Original line number Diff line number Diff line
@@ -116,7 +116,7 @@ func main() { 
	var torBinary string

	var obfs4proxyBinary string

	var webtunnelBinary string

	var testTimeout, cacheTimeout int

	var testTimeout, cacheTimeout, errorCacheTimeout int

	var logFile string



	flag.StringVar(&addr, "addr", ":5000", "Address to listen on.")
@@ -134,6 +134,7 @@ func main() { 
	flag.StringVar(&webtunnelBinary, "webtunnel", "./webtunnel", "Path to obfs4proxy executable.")

	flag.StringVar(&logFile, "log", "", "File to write logs to.")

	flag.IntVar(&testTimeout, "test-timeout", 60, "Test timeout in seconds.")

	flag.IntVar(&errorCacheTimeout, "error-cache-timeout", 1, "Test timeout in hours for tests that have errored.")

	flag.IntVar(&cacheTimeout, "cache-timeout", 18, "Cache timeout in hours.")

	flag.Parse()
@@ -188,6 +189,7 @@ func main() { 
		log.Printf("Could not read cache: %s", err)

	}

	cache.entryTimeout = time.Duration(cacheTimeout) * time.Hour

	cache.errorEntryTimeout = time.Duration(errorCacheTimeout) * time.Hour

	log.Printf("Set cache timeout to %s.", cache.entryTimeout)

	if printCache {

		printPrettyCache()