rpcclient: Add retry with backoffs to HTTP POST requests
Adds behavior similar to the retries of persistent RPC connections to HTTP request. * Initial backoff: 500ms * Linear increase * Max retries: 10 Room for future improvement: * Make configurable * Add jitter * Tests for retry behavior
This commit is contained in:
3nprob
John C. Vernaleo
parent
65e986844e
commit
cc7327c194
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@ -86,15 +86,11 @@ const (
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// connectionRetryInterval is the amount of time to wait in between
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// retries when automatically reconnecting to an RPC server.
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connectionRetryInterval = time.Second * 5
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)
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// sendPostDetails houses an HTTP POST request to send to an RPC server as well
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// as the original JSON-RPC command and a channel to reply on when the server
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// responds with the result.
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type sendPostDetails struct {
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httpRequest *http.Request
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jsonRequest *jsonRequest
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}
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// requestRetryInterval is the initial amount of time to wait in between
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// retries when sending HTTP POST requests.
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requestRetryInterval = time.Millisecond * 500
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)
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// jsonRequest holds information about a json request that is used to properly
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// detect, interpret, and deliver a reply to it.
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@ -183,7 +179,7 @@ type Client struct {
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// Networking infrastructure.
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sendChan chan []byte
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sendPostChan chan *sendPostDetails
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sendPostChan chan *jsonRequest
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connEstablished chan struct{}
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disconnect chan struct{}
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shutdown chan struct{}
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@ -765,10 +761,50 @@ out:
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// handleSendPostMessage handles performing the passed HTTP request, reading the
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// result, unmarshalling it, and delivering the unmarshalled result to the
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// provided response channel.
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func (c *Client) handleSendPostMessage(details *sendPostDetails) {
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jReq := details.jsonRequest
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log.Tracef("Sending command [%s] with id %d", jReq.method, jReq.id)
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httpResponse, err := c.httpClient.Do(details.httpRequest)
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func (c *Client) handleSendPostMessage(jReq *jsonRequest) {
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protocol := "http"
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if !c.config.DisableTLS {
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protocol = "https"
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}
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url := protocol + "://" + c.config.Host
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var err error
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var backoff time.Duration
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var httpResponse *http.Response
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tries := 10
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for i := 0; tries == 0 || i < tries; i++ {
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bodyReader := bytes.NewReader(jReq.marshalledJSON)
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httpReq, err := http.NewRequest("POST", url, bodyReader)
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if err != nil {
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jReq.responseChan <- &Response{result: nil, err: err}
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return
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}
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httpReq.Close = true
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httpReq.Header.Set("Content-Type", "application/json")
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for key, value := range c.config.ExtraHeaders {
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httpReq.Header.Set(key, value)
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}
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// Configure basic access authorization.
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user, pass, err := c.config.getAuth()
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if err != nil {
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jReq.responseChan <- &Response{result: nil, err: err}
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return
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}
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httpReq.SetBasicAuth(user, pass)
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httpResponse, err = c.httpClient.Do(httpReq)
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if err != nil {
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backoff = requestRetryInterval * time.Duration(i+1)
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if backoff > time.Minute {
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backoff = time.Minute
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}
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log.Debugf("Failed command [%s] with id %d attempt %d. Retrying in %v... \n", jReq.method, jReq.id, i, backoff)
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time.Sleep(backoff)
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continue
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}
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break
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}
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if err != nil {
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jReq.responseChan <- &Response{err: err}
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return
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@ -821,8 +857,8 @@ out:
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// Send any messages ready for send until the shutdown channel
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// is closed.
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select {
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case details := <-c.sendPostChan:
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c.handleSendPostMessage(details)
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case jReq := <-c.sendPostChan:
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c.handleSendPostMessage(jReq)
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case <-c.shutdown:
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break out
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@ -834,8 +870,8 @@ out:
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cleanup:
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for {
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select {
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case details := <-c.sendPostChan:
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details.jsonRequest.responseChan <- &Response{
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case jReq := <-c.sendPostChan:
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jReq.responseChan <- &Response{
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result: nil,
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err: ErrClientShutdown,
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}
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@ -852,7 +888,7 @@ cleanup:
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// sendPostRequest sends the passed HTTP request to the RPC server using the
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// HTTP client associated with the client. It is backed by a buffered channel,
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// so it will not block until the send channel is full.
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func (c *Client) sendPostRequest(httpReq *http.Request, jReq *jsonRequest) {
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func (c *Client) sendPostRequest(jReq *jsonRequest) {
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// Don't send the message if shutting down.
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select {
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case <-c.shutdown:
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@ -860,10 +896,9 @@ func (c *Client) sendPostRequest(httpReq *http.Request, jReq *jsonRequest) {
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default:
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}
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c.sendPostChan <- &sendPostDetails{
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jsonRequest: jReq,
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httpRequest: httpReq,
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}
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log.Tracef("Sending command [%s] with id %d", jReq.method, jReq.id)
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c.sendPostChan <- jReq
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}
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// newFutureError returns a new future result channel that already has the
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@ -885,42 +920,6 @@ func ReceiveFuture(f chan *Response) ([]byte, error) {
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return r.result, r.err
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}
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// sendPost sends the passed request to the server by issuing an HTTP POST
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// request using the provided response channel for the reply. Typically a new
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// connection is opened and closed for each command when using this method,
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// however, the underlying HTTP client might coalesce multiple commands
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// depending on several factors including the remote server configuration.
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func (c *Client) sendPost(jReq *jsonRequest) {
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// Generate a request to the configured RPC server.
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protocol := "http"
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if !c.config.DisableTLS {
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protocol = "https"
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}
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url := protocol + "://" + c.config.Host
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bodyReader := bytes.NewReader(jReq.marshalledJSON)
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httpReq, err := http.NewRequest("POST", url, bodyReader)
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if err != nil {
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jReq.responseChan <- &Response{result: nil, err: err}
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return
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}
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httpReq.Close = true
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httpReq.Header.Set("Content-Type", "application/json")
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for key, value := range c.config.ExtraHeaders {
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httpReq.Header.Set(key, value)
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}
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// Configure basic access authorization.
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user, pass, err := c.config.getAuth()
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if err != nil {
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jReq.responseChan <- &Response{result: nil, err: err}
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return
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}
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httpReq.SetBasicAuth(user, pass)
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log.Tracef("Sending command [%s] with id %d", jReq.method, jReq.id)
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c.sendPostRequest(httpReq, jReq)
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}
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// sendRequest sends the passed json request to the associated server using the
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// provided response channel for the reply. It handles both websocket and HTTP
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// POST mode depending on the configuration of the client.
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@ -935,7 +934,7 @@ func (c *Client) sendRequest(jReq *jsonRequest) {
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log.Warn(err)
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}
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} else {
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c.sendPost(jReq)
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c.sendPostRequest(jReq)
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}
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return
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}
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@ -1428,7 +1427,7 @@ func New(config *ConnConfig, ntfnHandlers *NotificationHandlers) (*Client, error
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ntfnHandlers: ntfnHandlers,
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ntfnState: newNotificationState(),
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sendChan: make(chan []byte, sendBufferSize),
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sendPostChan: make(chan *sendPostDetails, sendPostBufferSize),
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sendPostChan: make(chan *jsonRequest, sendPostBufferSize),
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connEstablished: connEstablished,
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disconnect: make(chan struct{}),
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shutdown: make(chan struct{}),
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@ -1642,7 +1641,7 @@ func (c *Client) sendAsync() FutureGetBulkResult {
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marshalledJSON: marshalledRequest,
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responseChan: responseChan,
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}
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c.sendPost(&request)
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c.sendPostRequest(&request)
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return responseChan
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}
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