| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.cassandra.locator; |
| |
| import java.net.InetAddress; |
| import java.net.UnknownHostException; |
| import java.util.Map; |
| import java.util.List; |
| |
| public interface DynamicEndpointSnitchMBean |
| { |
| public Map<InetAddress, Double> getScores(); |
| public int getUpdateInterval(); |
| public int getResetInterval(); |
| public double getBadnessThreshold(); |
| public String getSubsnitchClassName(); |
| public List<Double> dumpTimings(String hostname) throws UnknownHostException; |
| |
| /** |
| * Setting a Severity allows operators to inject preference information into the Dynamic Snitch |
| * replica selection. |
| * |
| * When choosing which replicas to participate in a read request, the DSnitch sorts replicas |
| * by response latency, and selects the fastest replicas. Latencies are normalized to a score |
| * from 0 to 1, with lower scores being faster. |
| * |
| * The Severity injected here will be added to the normalized score. |
| * |
| * Thus, adding a Severity greater than 1 will mean the replica will never be contacted |
| * (unless needed for ALL or if it is added later for rapid read protection). |
| * |
| * Conversely, adding a negative Severity means the replica will *always* be contacted. |
| * |
| * (The "Severity" term is historical and dates to when this was used to represent how |
| * badly background tasks like compaction were affecting a replica's performance. |
| * See CASSANDRA-3722 for when this was introduced and CASSANDRA-11738 for why it was removed.) |
| */ |
| public void setSeverity(double severity); |
| |
| /** |
| * @return the current manually injected Severity. |
| */ |
| public double getSeverity(); |
| } |