com.datastax.driver.core.policies.ReconnectionPolicy Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of cassandra-driver Show documentation
Show all versions of cassandra-driver Show documentation
Shaded version of DataStax Java Driver for Apache Cassandra
/*
* Copyright (C) 2012-2015 DataStax Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.datastax.driver.core.policies;
import com.datastax.driver.core.Cluster;
/**
* Policy that decides how often the reconnection to a dead node is attempted.
*
* Each time a node is detected dead (because a connection error occurs), a new
* {@code ReconnectionSchedule} instance is created (through the {@link #newSchedule()}).
* Then each call to the {@link ReconnectionSchedule#nextDelayMs} method of
* this instance will decide when the next reconnection attempt to this node
* will be tried.
*
* Note that if the driver receives a push notification from the Cassandra cluster
* that a node is UP, any existing {@code ReconnectionSchedule} on that node
* will be cancelled and a new one will be created (in effect, the driver reset
* the scheduler).
*
* The default {@link ExponentialReconnectionPolicy} policy is usually
* adequate.
*/
public interface ReconnectionPolicy {
/**
* Creates a new schedule for reconnection attempts.
*
* @return the created schedule.
*/
public ReconnectionSchedule newSchedule();
/**
* Schedules reconnection attempts to a node.
*/
public interface ReconnectionSchedule {
/**
* When to attempt the next reconnection.
*
* This method will be called once when the host is detected down to
* schedule the first reconnection attempt, and then once after each failed
* reconnection attempt to schedule the next one. Hence each call to this
* method are free to return a different value.
*
* @return a time in milliseconds to wait before attempting the next
* reconnection.
*/
public long nextDelayMs();
}
/**
* Gets invoked at cluster startup.
*
* @param cluster the cluster that this policy is associated with.
*/
void init(Cluster cluster);
/**
* Gets invoked at cluster shutdown.
*
* This gives the policy the opportunity to perform some cleanup, for instance stop threads that it might have started.
*/
void close();
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy