| /** |
| * 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.hadoop.hbase.replication.regionserver; |
| |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.util.EnvironmentEdgeManager; |
| |
| /** |
| * Per-peer per-node throttling controller for replication: enabled if |
| * bandwidth > 0, a cycle = 100ms, by throttling we guarantee data pushed |
| * to peer within each cycle won't exceed 'bandwidth' bytes |
| */ |
| @InterfaceAudience.Private |
| public class ReplicationThrottler { |
| private boolean enabled; |
| private double bandwidth; |
| private long cyclePushSize; |
| private long cycleStartTick; |
| |
| /** |
| * ReplicationThrottler constructor |
| * If bandwidth less than 1, throttling is disabled |
| * @param bandwidth per cycle(100ms) |
| */ |
| public ReplicationThrottler(final double bandwidth) { |
| this.bandwidth = bandwidth; |
| this.enabled = this.bandwidth > 0; |
| if (this.enabled) { |
| this.cyclePushSize = 0; |
| this.cycleStartTick = EnvironmentEdgeManager.currentTime(); |
| } |
| } |
| |
| /** |
| * If throttling is enabled |
| * @return true if throttling is enabled |
| */ |
| public boolean isEnabled() { |
| return this.enabled; |
| } |
| |
| /** |
| * Get how long the caller should sleep according to the current size and |
| * current cycle's total push size and start tick, return the sleep interval |
| * for throttling control. |
| * @param size is the size of edits to be pushed |
| * @return sleep interval for throttling control |
| */ |
| public long getNextSleepInterval(final int size) { |
| if (!this.enabled) { |
| return 0; |
| } |
| |
| long sleepTicks = 0; |
| long now = EnvironmentEdgeManager.currentTime(); |
| // 1. if cyclePushSize exceeds bandwidth, we need to sleep some |
| // following cycles to amortize, this case can occur when a single push |
| // exceeds the bandwidth |
| if ((double)this.cyclePushSize > bandwidth) { |
| double cycles = Math.ceil((double)this.cyclePushSize / bandwidth); |
| long shouldTillTo = this.cycleStartTick + (long)(cycles * 100); |
| if (shouldTillTo > now) { |
| sleepTicks = shouldTillTo - now; |
| } else { |
| // no reset in shipEdits since no sleep, so we need to reset cycleStartTick here! |
| this.cycleStartTick = now; |
| } |
| this.cyclePushSize = 0; |
| } else { |
| long nextCycleTick = this.cycleStartTick + 100; //a cycle is 100ms |
| if (now >= nextCycleTick) { |
| // 2. switch to next cycle if the current cycle has passed |
| this.cycleStartTick = now; |
| this.cyclePushSize = 0; |
| } else if (this.cyclePushSize > 0 && |
| (double)(this.cyclePushSize + size) >= bandwidth) { |
| // 3. delay the push to next cycle if exceeds throttling bandwidth. |
| // enforcing cyclePushSize > 0 to avoid the unnecessary sleep for case |
| // where a cycle's first push size(currentSize) > bandwidth |
| sleepTicks = nextCycleTick - now; |
| this.cyclePushSize = 0; |
| } |
| } |
| return sleepTicks; |
| } |
| |
| /** |
| * Add current size to the current cycle's total push size |
| * @param size is the current size added to the current cycle's |
| * total push size |
| */ |
| public void addPushSize(final int size) { |
| if (this.enabled) { |
| this.cyclePushSize += size; |
| } |
| } |
| |
| /** |
| * Reset the cycle start tick to NOW |
| */ |
| public void resetStartTick() { |
| if (this.enabled) { |
| this.cycleStartTick = EnvironmentEdgeManager.currentTime(); |
| } |
| } |
| |
| public void setBandwidth(double bandwidth) { |
| this.bandwidth = bandwidth; |
| this.enabled = this.bandwidth > 0; |
| } |
| } |