io.druid.java.util.common

Class RetryUtils

java.lang.Object

io.druid.java.util.common.RetryUtils

public class RetryUtils
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static Logger	log

Constructor Summary

Constructors

Constructor and Description
RetryUtils()

Method Summary

Modifier and Type	Method and Description
static long	nextRetrySleepMillis(int nTry)
static <T> T	retry(Callable<T> f, com.google.common.base.Predicate<Throwable> shouldRetry, int maxTries) Same as retry(Callable, Predicate, int, int) with quietTries = 0.
static <T> T	retry(Callable<T> f, com.google.common.base.Predicate<Throwable> shouldRetry, int quietTries, int maxTries) Retry an operation using fuzzy exponentially increasing backoff.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

log

public static final Logger log

Constructor Detail

RetryUtils

public RetryUtils()

Method Detail

retry

public static <T> T retry(Callable<T> f,
                          com.google.common.base.Predicate<Throwable> shouldRetry,
                          int quietTries,
                          int maxTries)
                   throws Exception

Retry an operation using fuzzy exponentially increasing backoff. The wait time after the nth failed attempt is min(60000ms, 1000ms * pow(2, n - 1)), fuzzed by a number drawn from a Gaussian distribution with mean 0 and standard deviation 0.2. If maxTries is exhausted, or if shouldRetry returns false, the last exception thrown by "f" will be thrown by this function.

Parameters:

f - the operation

shouldRetry - predicate determining whether we should retry after a particular exception thrown by "f"

quietTries - first quietTries attempts will log exceptions at DEBUG level rather than WARN

maxTries - maximum number of attempts

Returns:

result of the first successful operation

Throws:

Exception - if maxTries is exhausted, or shouldRetry returns false

retry

public static <T> T retry(Callable<T> f,
                          com.google.common.base.Predicate<Throwable> shouldRetry,
                          int maxTries)
                   throws Exception

Same as retry(Callable, Predicate, int, int) with quietTries = 0.

Throws:

Exception

nextRetrySleepMillis

public static long nextRetrySleepMillis(int nTry)