"net/url"
"os"
"strings"
+ "sync"
"testing"
"time"
var _ = check.Suite(&HandlerSuite{})
type HandlerSuite struct {
- cluster *arvados.Cluster
- handler *Handler
- logbuf *bytes.Buffer
- ctx context.Context
- cancel context.CancelFunc
+ cluster *arvados.Cluster
+ handler *Handler
+ railsSpy *arvadostest.Proxy
+ logbuf *bytes.Buffer
+ ctx context.Context
+ cancel context.CancelFunc
}
func (s *HandlerSuite) SetUpTest(c *check.C) {
s.cluster.API.RequestTimeout = arvados.Duration(5 * time.Minute)
s.cluster.TLS.Insecure = true
arvadostest.SetServiceURL(&s.cluster.Services.RailsAPI, "https://"+os.Getenv("ARVADOS_TEST_API_HOST"))
+ s.railsSpy = arvadostest.NewProxy(c, s.cluster.Services.RailsAPI)
+ arvadostest.SetServiceURL(&s.cluster.Services.RailsAPI, s.railsSpy.URL.String())
arvadostest.SetServiceURL(&s.cluster.Services.Controller, "http://localhost:/")
s.handler = newHandler(s.ctx, s.cluster, "", prometheus.NewRegistry()).(*Handler)
}
}
}
+func (s *HandlerSuite) TestDiscoveryDocCache(c *check.C) {
+ countRailsReqs := func() int {
+ n := 0
+ for _, req := range s.railsSpy.RequestDumps {
+ if bytes.Contains(req, []byte("/discovery/v1/apis/arvados/v1/rest")) {
+ n++
+ }
+ }
+ return n
+ }
+ getDD := func() int {
+ req := httptest.NewRequest(http.MethodGet, "/discovery/v1/apis/arvados/v1/rest", nil)
+ resp := httptest.NewRecorder()
+ s.handler.ServeHTTP(resp, req)
+ if resp.Code == http.StatusOK {
+ var dd arvados.DiscoveryDocument
+ err := json.Unmarshal(resp.Body.Bytes(), &dd)
+ c.Check(err, check.IsNil)
+ c.Check(dd.Schemas["Collection"].UUIDPrefix, check.Equals, "4zz18")
+ }
+ return resp.Code
+ }
+ getDDConcurrently := func(n int, expectCode int, checkArgs ...interface{}) *sync.WaitGroup {
+ var wg sync.WaitGroup
+ for i := 0; i < n; i++ {
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ c.Check(getDD(), check.Equals, append([]interface{}{expectCode}, checkArgs...)...)
+ }()
+ }
+ return &wg
+ }
+ clearCache := func() {
+ for path := range s.handler.cache {
+ s.handler.cache[path] = &cacheEnt{}
+ }
+ }
+ expireCache := func() {
+ for _, ent := range s.handler.cache {
+ ent.refreshAfter = time.Now()
+ }
+ }
+ waitPendingUpdates := func() {
+ for _, ent := range s.handler.cache {
+ ent.refreshLock.Lock()
+ defer ent.refreshLock.Unlock()
+ ent.mtx.Lock()
+ defer ent.mtx.Unlock()
+ }
+ }
+
+ // Easy path: first req fetches, subsequent reqs use cache.
+ c.Check(countRailsReqs(), check.Equals, 0)
+ c.Check(getDD(), check.Equals, http.StatusOK)
+ c.Check(countRailsReqs(), check.Equals, 1)
+ c.Check(getDD(), check.Equals, http.StatusOK)
+ c.Check(countRailsReqs(), check.Equals, 1)
+ c.Check(getDD(), check.Equals, http.StatusOK)
+ c.Check(countRailsReqs(), check.Equals, 1)
+
+ // To guarantee we have concurrent requests, we set up
+ // railsSpy to hold up the Handler's outgoing requests until
+ // we send to (or close) holdReqs.
+ holdReqs := make(chan struct{})
+ s.railsSpy.Director = func(*http.Request) {
+ <-holdReqs
+ }
+
+ // Race at startup: first req fetches, other concurrent reqs
+ // wait for the initial fetch to complete, then all return.
+ clearCache()
+ reqsBefore := countRailsReqs()
+ wg := getDDConcurrently(5, http.StatusOK, check.Commentf("race at startup"))
+ close(holdReqs)
+ wg.Wait()
+ c.Check(countRailsReqs(), check.Equals, reqsBefore+1)
+
+ // Race after expiry: concurrent reqs return the cached data
+ // but initiate a new fetch in the background.
+ expireCache()
+ holdReqs = make(chan struct{})
+ wg = getDDConcurrently(5, http.StatusOK, check.Commentf("race after expiry"))
+ reqsBefore = countRailsReqs()
+ close(holdReqs)
+ wg.Wait()
+ for deadline := time.Now().Add(time.Second); time.Now().Before(deadline) && countRailsReqs() < reqsBefore+1; {
+ time.Sleep(time.Second / 100)
+ }
+ c.Check(countRailsReqs(), check.Equals, reqsBefore+1)
+
+ // Configure railsSpy to return an error when wantError==true.
+ var wantError bool
+ s.railsSpy.Director = func(req *http.Request) {
+ if wantError {
+ req.Method = "MAKE-COFFEE"
+ }
+ }
+
+ // Error at startup (empty cache) => caller gets error, and we
+ // make an upstream attempt for each incoming request because
+ // we have nothing better to return
+ clearCache()
+ wantError = true
+ reqsBefore = countRailsReqs()
+ holdReqs = make(chan struct{})
+ wg = getDDConcurrently(5, http.StatusBadGateway, check.Commentf("error at startup"))
+ close(holdReqs)
+ wg.Wait()
+ c.Check(countRailsReqs(), check.Equals, reqsBefore+5)
+
+ // Error condition clears => caller gets OK, cache is warmed
+ // up
+ wantError = false
+ reqsBefore = countRailsReqs()
+ getDDConcurrently(5, http.StatusOK, check.Commentf("success after errors at startup")).Wait()
+ c.Check(countRailsReqs(), check.Equals, reqsBefore+1)
+
+ // Error with warm cache => caller gets OK (with no attempt to
+ // re-fetch)
+ wantError = true
+ reqsBefore = countRailsReqs()
+ getDDConcurrently(5, http.StatusOK, check.Commentf("error with warm cache")).Wait()
+ c.Check(countRailsReqs(), check.Equals, reqsBefore)
+ expireCache()
+
+ // Error with expired cache => caller gets OK with stale data
+ // while the re-fetch is attempted in the background
+ reqsBefore = countRailsReqs()
+ holdReqs = make(chan struct{})
+ getDDConcurrently(5, http.StatusOK, check.Commentf("error with expired cache")).Wait()
+ close(holdReqs)
+ // Only one attempt to re-fetch (holdReqs ensured the first
+ // update took long enough for the last incoming request to
+ // arrive)
+ c.Check(countRailsReqs(), check.Equals, reqsBefore+1)
+
+ waitPendingUpdates()
+ expireCache()
+ wantError = false
+ reqsBefore = countRailsReqs()
+ holdReqs = make(chan struct{})
+ getDDConcurrently(5, http.StatusOK, check.Commentf("refresh cache after error condition clears")).Wait()
+ close(holdReqs)
+ c.Check(countRailsReqs(), check.Equals, reqsBefore+1)
+}
+
func (s *HandlerSuite) TestVocabularyExport(c *check.C) {
voc := `{
"strict_tags": false,
projects / arvados.git / commitdiff