"os"
"regexp"
"strings"
+ "time"
)
type StringMatcher func(string) bool
var MissingArvadosApiToken = errors.New("Missing required environment variable ARVADOS_API_TOKEN")
var ErrInvalidArgument = errors.New("Invalid argument")
+// A common failure mode is to reuse a keepalive connection that has been
+// terminated (in a way that we can't detect) for being idle too long.
+// POST and DELETE are not safe to retry automatically, so we minimize
+// such failures by always using a new or recently active socket.
+var MaxIdleConnectionDuration = 30 * time.Second
+
+var RetryDelay = 2 * time.Second
+
// Indicates an error that was returned by the API server.
type APIServerError struct {
// Address of server returning error, of the form "host:port".
// Information about how to contact the Arvados server
type ArvadosClient struct {
+ // https
+ Scheme string
+
// Arvados API server, form "host:port"
ApiServer string
// Discovery document
DiscoveryDoc Dict
-}
-// APIConfig struct consists of:
-// APIToken string
-// APIHost string
-// APIHostInsecure bool
-// ExternalClient bool
-type APIConfig struct {
- APIToken string
- APIHost string
- APIHostInsecure bool
- ExternalClient bool
+ lastClosedIdlesAt time.Time
+
+ // Number of retries
+ Retries int
}
// Create a new ArvadosClient, initialized with standard Arvados environment
external := matchTrue.MatchString(os.Getenv("ARVADOS_EXTERNAL_CLIENT"))
ac = ArvadosClient{
+ Scheme: "https",
ApiServer: os.Getenv("ARVADOS_API_HOST"),
ApiToken: os.Getenv("ARVADOS_API_TOKEN"),
ApiInsecure: insecure,
Client: &http.Client{Transport: &http.Transport{
TLSClientConfig: &tls.Config{InsecureSkipVerify: insecure}}},
- External: external}
+ External: external,
+ Retries: 2}
if ac.ApiServer == "" {
return ac, MissingArvadosApiHost
return ac, MissingArvadosApiToken
}
+ ac.lastClosedIdlesAt = time.Now()
+
return ac, err
}
// CallRaw is the same as Call() but returns a Reader that reads the
// response body, instead of taking an output object.
func (c ArvadosClient) CallRaw(method string, resourceType string, uuid string, action string, parameters Dict) (reader io.ReadCloser, err error) {
- var req *http.Request
-
+ scheme := c.Scheme
+ if scheme == "" {
+ scheme = "https"
+ }
u := url.URL{
- Scheme: "https",
+ Scheme: scheme,
Host: c.ApiServer}
if resourceType != API_DISCOVERY_RESOURCE {
}
}
- if method == "GET" || method == "HEAD" {
- u.RawQuery = vals.Encode()
- if req, err = http.NewRequest(method, u.String(), nil); err != nil {
- return nil, err
- }
- } else {
- if req, err = http.NewRequest(method, u.String(), bytes.NewBufferString(vals.Encode())); err != nil {
- return nil, err
- }
- req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+ retryable := false
+ switch method {
+ case "GET", "HEAD", "PUT", "OPTIONS", "DELETE":
+ retryable = true
}
- // Add api token header
- req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", c.ApiToken))
- if c.External {
- req.Header.Add("X-External-Client", "1")
+ // Non-retryable methods such as POST are not safe to retry automatically,
+ // so we minimize such failures by always using a new or recently active socket
+ if !retryable {
+ if time.Since(c.lastClosedIdlesAt) > MaxIdleConnectionDuration {
+ c.lastClosedIdlesAt = time.Now()
+ c.Client.Transport.(*http.Transport).CloseIdleConnections()
+ }
}
// Make the request
+ var req *http.Request
var resp *http.Response
- if resp, err = c.Client.Do(req); err != nil {
- return nil, err
- }
- if resp.StatusCode == http.StatusOK {
- return resp.Body, nil
+ for attempt := 0; attempt <= c.Retries; attempt++ {
+ if method == "GET" || method == "HEAD" {
+ u.RawQuery = vals.Encode()
+ if req, err = http.NewRequest(method, u.String(), nil); err != nil {
+ return nil, err
+ }
+ } else {
+ if req, err = http.NewRequest(method, u.String(), bytes.NewBufferString(vals.Encode())); err != nil {
+ return nil, err
+ }
+ req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+ }
+
+ // Add api token header
+ req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", c.ApiToken))
+ if c.External {
+ req.Header.Add("X-External-Client", "1")
+ }
+
+ resp, err = c.Client.Do(req)
+ if err != nil {
+ if retryable {
+ time.Sleep(RetryDelay)
+ continue
+ } else {
+ return nil, err
+ }
+ }
+
+ if resp.StatusCode == http.StatusOK {
+ return resp.Body, nil
+ }
+
+ defer resp.Body.Close()
+
+ switch resp.StatusCode {
+ case 408, 409, 422, 423, 500, 502, 503, 504:
+ time.Sleep(RetryDelay)
+ continue
+ default:
+ return nil, newAPIServerError(c.ApiServer, resp)
+ }
}
- defer resp.Body.Close()
- return nil, newAPIServerError(c.ApiServer, resp)
+ if resp != nil {
+ return nil, newAPIServerError(c.ApiServer, resp)
+ }
+ return nil, err
}
func newAPIServerError(ServerAddress string, resp *http.Response) APIServerError {
// Returns a non-nil error if an error occurs making the API call, the
// API responds with a non-successful HTTP status, or an error occurs
// parsing the response body.
-func (c ArvadosClient) Call(method string, resourceType string, uuid string, action string, parameters Dict, output interface{}) error {
+func (c ArvadosClient) Call(method, resourceType, uuid, action string, parameters Dict, output interface{}) error {
reader, err := c.CallRaw(method, resourceType, uuid, action, parameters)
if reader != nil {
defer reader.Close()
projects / arvados.git / blobdiff