net.snowflake.client.jdbc.RestRequest Maven / Gradle / Ivy
/*
* Copyright (c) 2012-2017 Snowflake Computing Inc. All rights reserved.
*/
package net.snowflake.client.jdbc;
import net.snowflake.client.core.Event;
import net.snowflake.client.core.EventUtil;
import java.io.IOException;
import net.snowflake.client.log.SFLogger;
import net.snowflake.client.log.SFLoggerFactory;
import net.snowflake.client.core.HttpUtil;
import net.snowflake.common.core.SqlState;
import java.net.URI;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.utils.URIBuilder;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* This is an abstraction on top of http client.
*
* Currently it only has one method for retrying http request execution so that
* the same logic doesn't have to be replicated at difference places where retry
* is needed.
*
* @author jhuang
*/
public class RestRequest
{
static final SFLogger logger = SFLoggerFactory.getLogger(RestRequest.class);
// min backoff in milli before we retry due to transient issues
static private long minBackoffInMilli = 1000;
// max backoff in milli before we retry due to transient issues
// we double the backoff after each retry till we reach the max backoff
static private long maxBackoffInMilli = 16000;
// retry at least once even if timeout limit has been reached
static private int MIN_RETRY_COUNT = 1;
/**
* Execute an http request with retry logic.
*
* @param httpClient client object used to communicate with other machine
* @param httpRequest request object contains all the request information
* @param retryTimeout : retry timeout (in seconds)
* @param injectSocketTimeout : simulate socket timeout
* @param canceling canceling flag
* @return HttpResponse Object get from server
* @throws java.io.IOException jave io exception
* @throws net.snowflake.client.jdbc.SnowflakeSQLException
* Request timeout Exception or Illegal State Exception i.e.
* connection is already shutdown etc
*/
static public HttpResponse execute(
HttpClient httpClient,
HttpRequestBase httpRequest,
long retryTimeout,
int injectSocketTimeout,
AtomicBoolean canceling) throws IOException, SnowflakeSQLException
{
HttpResponse response = null;
// start time for each request,
// used for keeping track how much time we have spent
// due to network issues so that we can compare against the user
// specified network timeout to make sure we do not retry infinitely
// when there are transient network/GS issues.
long startTimePerRequest = System.currentTimeMillis();
// total elapsed time due to transient issues.
long elapsedMilliForTransientIssues = 0;
// amount of time to wait for backing off before retry
long backoffInMilli = minBackoffInMilli;
// elapsed in millisecond for last call, used for calculating the
// remaining amount of time to sleep:
// (backoffInMilli - elapsedMilliForLastCall)
long elapsedMilliForLastCall = 0;
int retryCount = 0;
int origSocketTimeout = 0;
Exception savedEx = null;
// try request till we get a good response or retry timeout
while (true)
{
logger.debug("Retry count: {}", retryCount);
try
{
// update start time
startTimePerRequest = System.currentTimeMillis();
// for first call, simulate a socket timeout by setting socket timeout
// to the injected socket timeout value
if ((injectSocketTimeout !=0) && retryCount == 0)
{
logger.info("Injecting socket timeout by setting " +
"socket timeout to {} millisecond ", injectSocketTimeout);
httpRequest.setConfig(
HttpUtil.getDefaultRequestConfigWithSocketTimeout(
injectSocketTimeout));
}
/**
* Add retry=true for the first retry request
* GS can uses the parameter for optimization. Specifically GS
* will only check metadata database to see if a query has been running
* for a retry request. This way for the majority of query requests
* which are not part of retry we don't have to pay the performance
* overhead of looking up in metadata database.
*/
if (retryCount == 1)
{
URI uri = (new URIBuilder(httpRequest.getURI())).
addParameter("retry", "true").build();
httpRequest.setURI(uri);
}
response = httpClient.execute(httpRequest);
}
catch(Exception ex)
{
// if exception is caused by illegal state, e.g shutdown of http client
// because of closing of connection, stop retrying
if (ex instanceof IllegalStateException)
{
throw new SnowflakeSQLException(ex,
ErrorCode.INVALID_STATE.getSqlState(),
ErrorCode.INVALID_STATE.getMessageCode(),
((IllegalStateException)ex).getMessage());
}
savedEx = ex;
// if the request took more than 5 min (socket timeout) log an error
if ((System.currentTimeMillis() - startTimePerRequest) > 300000)
{
logger.error("HTTP request took longer than 5 min: {} sec",
(System.currentTimeMillis() - startTimePerRequest)/1000);
}
logger.warn("Exception encountered for: " +
httpRequest.toString(), ex);
}
finally
{
// Reset the socket timeout to its original value if it is not the
// very first iteration.
if ((injectSocketTimeout != 0) && retryCount == 0)
{
httpRequest.setConfig(
HttpUtil.getDefaultRequestConfigWithSocketTimeout(
origSocketTimeout));
}
}
/**
* If we got a response and the status code is not one of those
* transient failures, no more retry
*
* SNOW-16385: retry for any 5xx errors
*/
if (response != null &&
(response.getStatusLine().getStatusCode() < 500 || // service unavailable
response.getStatusLine().getStatusCode() >= 600) && // gateway timeout
response.getStatusLine().getStatusCode() != 408 && // request timeout
response.getStatusLine().getStatusCode() != 403) // intermittent AWS access issue
{
logger.debug("HTTP response code: {}",
response.getStatusLine().getStatusCode());
if (response.getStatusLine().getStatusCode() != 200)
{
logger.debug("Got error response which is not retriable, " +
"http status={}, request={}",
new Object[]{
response.getStatusLine().getStatusCode(),
httpRequest});
EventUtil.triggerBasicEvent(
Event.EventType.NETWORK_ERROR,
"StatusCode: " + response.getStatusLine().getStatusCode() +
", Reason: " + response.getStatusLine().getReasonPhrase() +
", Request: " + httpRequest.toString(),
false);
}
break;
}
else
{
if (response != null)
logger.warn("HTTP response not ok: status code={}, "
+ "request={}",
new Object[]{
response.getStatusLine().getStatusCode(),
httpRequest});
else
logger.warn("Null response for request={}", httpRequest);
// get the elapsed time for the last request
elapsedMilliForLastCall =
System.currentTimeMillis() - startTimePerRequest;
// check canceling flag
if (canceling != null && canceling.get())
{
logger.info(
"Stop retrying since canceling is requested");
break;
}
if (retryTimeout > 0)
{
// increment total elapsed due to transient issues
elapsedMilliForTransientIssues += elapsedMilliForLastCall;
// check if the total elapsed time for transient issues has exceeded
// the retry timeout and we retry at least the min, if so, we will not
// retry
if (((elapsedMilliForTransientIssues / 1000) > retryTimeout) &&
retryCount >= MIN_RETRY_COUNT)
{
logger.error(
"Stop retrying since elapsed time due to network "
+ "issues has reached timeout. Elapsed=" +
elapsedMilliForTransientIssues +
" milliseconds, timeout=" +
retryTimeout + " seconds");
// rethrow the timeout exception
if (response == null && savedEx != null)
{
throw new SnowflakeSQLException(SqlState.IO_ERROR,
ErrorCode.NETWORK_ERROR.getMessageCode(),
"Exception encountered for HTTP request: " +
savedEx.getMessage());
}
// no more retry
break;
}
}
logger.info("Retrying request: {}", httpRequest);
// sleep for backoff - elapsed amount of time
if (backoffInMilli > elapsedMilliForLastCall)
{
try {
Thread.sleep(backoffInMilli - elapsedMilliForLastCall);
elapsedMilliForTransientIssues +=
(backoffInMilli - elapsedMilliForLastCall);
}
catch (InterruptedException ex1)
{
logger.info(
"Backoff sleep before retrying login got interrupted");
}
}
// increment backoff unless it is already the max
if (backoffInMilli < maxBackoffInMilli)
backoffInMilli *= 2;
// release connection before retry
httpRequest.releaseConnection();
retryCount++;
}
}
if (response == null)
logger.error("Returning null response for request: {}",
httpRequest);
else if (response.getStatusLine().getStatusCode() != 200)
logger.error("Got error response: " +
"http status={}, request={}",
new Object[]{
response.getStatusLine().getStatusCode(),
httpRequest});
return response;
}
}
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