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org.apache.hadoop.ipc.DecayRpcScheduler Maven / Gradle / Ivy
/**
* 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.ipc;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicLongArray;
import java.util.concurrent.atomic.AtomicReference;
import javax.management.ObjectName;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;
import com.google.common.base.Preconditions;
import com.google.common.util.concurrent.AtomicDoubleArray;
import org.apache.commons.lang3.exception.ExceptionUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeys;
import org.apache.hadoop.ipc.metrics.DecayRpcSchedulerDetailedMetrics;
import org.apache.hadoop.metrics2.MetricsCollector;
import org.apache.hadoop.metrics2.MetricsRecordBuilder;
import org.apache.hadoop.metrics2.MetricsSource;
import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
import org.apache.hadoop.metrics2.lib.Interns;
import org.apache.hadoop.metrics2.util.MBeans;
import org.apache.hadoop.metrics2.util.Metrics2Util.NameValuePair;
import org.apache.hadoop.metrics2.util.Metrics2Util.TopN;
import com.google.common.annotations.VisibleForTesting;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.hadoop.ipc.ProcessingDetails.Timing;
/**
* The decay RPC scheduler tracks the cost of incoming requests in a map, then
* decays the costs at a fixed time interval. The scheduler is optimized
* for large periods (on the order of seconds), as it offloads work to the
* decay sweep.
*/
public class DecayRpcScheduler implements RpcScheduler,
DecayRpcSchedulerMXBean, MetricsSource {
/**
* Period controls how many milliseconds between each decay sweep.
*/
public static final String IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_KEY =
"decay-scheduler.period-ms";
public static final long IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_DEFAULT =
5000;
@Deprecated
public static final String IPC_FCQ_DECAYSCHEDULER_PERIOD_KEY =
"faircallqueue.decay-scheduler.period-ms";
/**
* Decay factor controls how much each cost is suppressed by on each sweep.
* Valid numbers are > 0 and < 1. Decay factor works in tandem with
* period
* to control how long the scheduler remembers an identity.
*/
public static final String IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_KEY =
"decay-scheduler.decay-factor";
public static final double IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_DEFAULT =
0.5;
@Deprecated
public static final String IPC_FCQ_DECAYSCHEDULER_FACTOR_KEY =
"faircallqueue.decay-scheduler.decay-factor";
/**
* Thresholds are specified as integer percentages, and specify which usage
* range each queue will be allocated to. For instance, specifying the list
* 10, 40, 80
* implies 4 queues, with
* - q3 from 80% up
* - q2 from 40 up to 80
* - q1 from 10 up to 40
* - q0 otherwise.
*/
public static final String IPC_DECAYSCHEDULER_THRESHOLDS_KEY =
"decay-scheduler.thresholds";
@Deprecated
public static final String IPC_FCQ_DECAYSCHEDULER_THRESHOLDS_KEY =
"faircallqueue.decay-scheduler.thresholds";
// Specifies the identity to use when the IdentityProvider cannot handle
// a schedulable.
public static final String DECAYSCHEDULER_UNKNOWN_IDENTITY =
"IdentityProvider.Unknown";
public static final String
IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_KEY =
"decay-scheduler.backoff.responsetime.enable";
public static final Boolean
IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_DEFAULT = false;
// Specifies the average response time (ms) thresholds of each
// level to trigger backoff
public static final String
IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_THRESHOLDS_KEY =
"decay-scheduler.backoff.responsetime.thresholds";
// Specifies the top N user's call count and scheduler decision
// Metrics2 Source
public static final String DECAYSCHEDULER_METRICS_TOP_USER_COUNT =
"decay-scheduler.metrics.top.user.count";
public static final int DECAYSCHEDULER_METRICS_TOP_USER_COUNT_DEFAULT = 10;
public static final Logger LOG =
LoggerFactory.getLogger(DecayRpcScheduler.class);
private static final ObjectWriter WRITER = new ObjectMapper().writer();
// Track the decayed and raw (no decay) number of calls for each schedulable
// identity from all previous decay windows: idx 0 for decayed call cost and
// idx 1 for the raw call cost
private final ConcurrentHashMap> callCosts =
new ConcurrentHashMap>();
// Should be the sum of all AtomicLongs in decayed callCosts
private final AtomicLong totalDecayedCallCost = new AtomicLong();
// The sum of all AtomicLongs in raw callCosts
private final AtomicLong totalRawCallCost = new AtomicLong();
// Track total call count and response time in current decay window
private final AtomicLongArray responseTimeCountInCurrWindow;
private final AtomicLongArray responseTimeTotalInCurrWindow;
// Track average response time in previous decay window
private final AtomicDoubleArray responseTimeAvgInLastWindow;
private final AtomicLongArray responseTimeCountInLastWindow;
// RPC queue time rates per queue
private final DecayRpcSchedulerDetailedMetrics
decayRpcSchedulerDetailedMetrics;
// Pre-computed scheduling decisions during the decay sweep are
// atomically swapped in as a read-only map
private final AtomicReference> scheduleCacheRef =
new AtomicReference>();
// Tune the behavior of the scheduler
private final long decayPeriodMillis; // How long between each tick
private final double decayFactor; // nextCost = currentCost * decayFactor
private final int numLevels;
private final double[] thresholds;
private final IdentityProvider identityProvider;
private final boolean backOffByResponseTimeEnabled;
private final long[] backOffResponseTimeThresholds;
private final String namespace;
private final int topUsersCount; // e.g., report top 10 users' metrics
private static final double PRECISION = 0.0001;
private MetricsProxy metricsProxy;
private final CostProvider costProvider;
/**
* This TimerTask will call decayCurrentCosts until
* the scheduler has been garbage collected.
*/
public static class DecayTask extends TimerTask {
private WeakReference schedulerRef;
private Timer timer;
public DecayTask(DecayRpcScheduler scheduler, Timer timer) {
this.schedulerRef = new WeakReference(scheduler);
this.timer = timer;
}
@Override
public void run() {
DecayRpcScheduler sched = schedulerRef.get();
if (sched != null) {
sched.decayCurrentCosts();
} else {
// Our scheduler was garbage collected since it is no longer in use,
// so we should terminate the timer as well
timer.cancel();
timer.purge();
}
}
}
/**
* Create a decay scheduler.
* @param numLevels number of priority levels
* @param ns config prefix, so that we can configure multiple schedulers
* in a single instance.
* @param conf configuration to use.
*/
public DecayRpcScheduler(int numLevels, String ns, Configuration conf) {
if(numLevels < 1) {
throw new IllegalArgumentException("Number of Priority Levels must be " +
"at least 1");
}
this.numLevels = numLevels;
this.namespace = ns;
this.decayFactor = parseDecayFactor(ns, conf);
this.decayPeriodMillis = parseDecayPeriodMillis(ns, conf);
this.identityProvider = this.parseIdentityProvider(ns, conf);
this.costProvider = this.parseCostProvider(ns, conf);
this.thresholds = parseThresholds(ns, conf, numLevels);
this.backOffByResponseTimeEnabled = parseBackOffByResponseTimeEnabled(ns,
conf);
this.backOffResponseTimeThresholds =
parseBackOffResponseTimeThreshold(ns, conf, numLevels);
// Setup response time metrics
responseTimeTotalInCurrWindow = new AtomicLongArray(numLevels);
responseTimeCountInCurrWindow = new AtomicLongArray(numLevels);
responseTimeAvgInLastWindow = new AtomicDoubleArray(numLevels);
responseTimeCountInLastWindow = new AtomicLongArray(numLevels);
topUsersCount =
conf.getInt(DECAYSCHEDULER_METRICS_TOP_USER_COUNT,
DECAYSCHEDULER_METRICS_TOP_USER_COUNT_DEFAULT);
Preconditions.checkArgument(topUsersCount > 0,
"the number of top users for scheduler metrics must be at least 1");
decayRpcSchedulerDetailedMetrics =
DecayRpcSchedulerDetailedMetrics.create(ns);
decayRpcSchedulerDetailedMetrics.init(numLevels);
// Setup delay timer
Timer timer = new Timer(true);
DecayTask task = new DecayTask(this, timer);
timer.scheduleAtFixedRate(task, decayPeriodMillis, decayPeriodMillis);
metricsProxy = MetricsProxy.getInstance(ns, numLevels, this);
recomputeScheduleCache();
}
private CostProvider parseCostProvider(String ns, Configuration conf) {
List providers = conf.getInstances(
ns + "." + CommonConfigurationKeys.IPC_COST_PROVIDER_KEY,
CostProvider.class);
if (providers.size() < 1) {
LOG.info("CostProvider not specified, defaulting to DefaultCostProvider");
return new DefaultCostProvider();
} else if (providers.size() > 1) {
LOG.warn("Found multiple CostProviders; using: {}",
providers.get(0).getClass());
}
CostProvider provider = providers.get(0); // use the first
provider.init(ns, conf);
return provider;
}
// Load configs
private IdentityProvider parseIdentityProvider(String ns,
Configuration conf) {
List providers = conf.getInstances(
ns + "." + CommonConfigurationKeys.IPC_IDENTITY_PROVIDER_KEY,
IdentityProvider.class);
if (providers.size() < 1) {
LOG.info("IdentityProvider not specified, " +
"defaulting to UserIdentityProvider");
return new UserIdentityProvider();
}
return providers.get(0); // use the first
}
private static double parseDecayFactor(String ns, Configuration conf) {
double factor = conf.getDouble(ns + "." +
IPC_FCQ_DECAYSCHEDULER_FACTOR_KEY, 0.0);
if (factor == 0.0) {
factor = conf.getDouble(ns + "." +
IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_KEY,
IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_DEFAULT);
} else if ((factor > 0.0) && (factor < 1)) {
LOG.warn(IPC_FCQ_DECAYSCHEDULER_FACTOR_KEY +
" is deprecated. Please use " +
IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_KEY + ".");
}
if (factor <= 0 || factor >= 1) {
throw new IllegalArgumentException("Decay Factor " +
"must be between 0 and 1");
}
return factor;
}
private static long parseDecayPeriodMillis(String ns, Configuration conf) {
long period = conf.getLong(ns + "." +
IPC_FCQ_DECAYSCHEDULER_PERIOD_KEY,
0);
if (period == 0) {
period = conf.getLong(ns + "." +
IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_KEY,
IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_DEFAULT);
} else if (period > 0) {
LOG.warn((IPC_FCQ_DECAYSCHEDULER_PERIOD_KEY +
" is deprecated. Please use " +
IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_KEY));
}
if (period <= 0) {
throw new IllegalArgumentException("Period millis must be >= 0");
}
return period;
}
private static double[] parseThresholds(String ns, Configuration conf,
int numLevels) {
int[] percentages = conf.getInts(ns + "." +
IPC_FCQ_DECAYSCHEDULER_THRESHOLDS_KEY);
if (percentages.length == 0) {
percentages = conf.getInts(ns + "." + IPC_DECAYSCHEDULER_THRESHOLDS_KEY);
if (percentages.length == 0) {
return getDefaultThresholds(numLevels);
}
} else {
LOG.warn(IPC_FCQ_DECAYSCHEDULER_THRESHOLDS_KEY +
" is deprecated. Please use " +
IPC_DECAYSCHEDULER_THRESHOLDS_KEY);
}
if (percentages.length != numLevels-1) {
throw new IllegalArgumentException("Number of thresholds should be " +
(numLevels-1) + ". Was: " + percentages.length);
}
// Convert integer percentages to decimals
double[] decimals = new double[percentages.length];
for (int i = 0; i < percentages.length; i++) {
decimals[i] = percentages[i] / 100.0;
}
return decimals;
}
/**
* Generate default thresholds if user did not specify. Strategy is
* to halve each time, since queue usage tends to be exponential.
* So if numLevels is 4, we would generate: double[]{0.125, 0.25, 0.5}
* which specifies the boundaries between each queue's usage.
* @param numLevels number of levels to compute for
* @return array of boundaries of length numLevels - 1
*/
private static double[] getDefaultThresholds(int numLevels) {
double[] ret = new double[numLevels - 1];
double div = Math.pow(2, numLevels - 1);
for (int i = 0; i < ret.length; i++) {
ret[i] = Math.pow(2, i)/div;
}
return ret;
}
private static long[] parseBackOffResponseTimeThreshold(String ns,
Configuration conf, int numLevels) {
long[] responseTimeThresholds = conf.getTimeDurations(ns + "." +
IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_THRESHOLDS_KEY,
TimeUnit.MILLISECONDS);
// backoff thresholds not specified
if (responseTimeThresholds.length == 0) {
return getDefaultBackOffResponseTimeThresholds(numLevels);
}
// backoff thresholds specified but not match with the levels
if (responseTimeThresholds.length != numLevels) {
throw new IllegalArgumentException(
"responseTimeThresholds must match with the number of priority " +
"levels");
}
// invalid thresholds
for (long responseTimeThreshold: responseTimeThresholds) {
if (responseTimeThreshold <= 0) {
throw new IllegalArgumentException(
"responseTimeThreshold millis must be >= 0");
}
}
return responseTimeThresholds;
}
// 10s for level 0, 20s for level 1, 30s for level 2, ...
private static long[] getDefaultBackOffResponseTimeThresholds(int numLevels) {
long[] ret = new long[numLevels];
for (int i = 0; i < ret.length; i++) {
ret[i] = 10000*(i+1);
}
return ret;
}
private static Boolean parseBackOffByResponseTimeEnabled(String ns,
Configuration conf) {
return conf.getBoolean(ns + "." +
IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_KEY,
IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_DEFAULT);
}
/**
* Decay the stored costs for each user and clean as necessary.
* This method should be called periodically in order to keep
* costs current.
*/
private void decayCurrentCosts() {
LOG.debug("Start to decay current costs.");
try {
long totalDecayedCost = 0;
long totalRawCost = 0;
Iterator>> it =
callCosts.entrySet().iterator();
while (it.hasNext()) {
Map.Entry> entry = it.next();
AtomicLong decayedCost = entry.getValue().get(0);
AtomicLong rawCost = entry.getValue().get(1);
// Compute the next value by reducing it by the decayFactor
totalRawCost += rawCost.get();
long currentValue = decayedCost.get();
long nextValue = (long) (currentValue * decayFactor);
totalDecayedCost += nextValue;
decayedCost.set(nextValue);
LOG.debug(
"Decaying costs for the user: {}, its decayedCost: {}, rawCost: {}",
entry.getKey(), nextValue, rawCost.get());
if (nextValue == 0) {
LOG.debug("The decayed cost for the user {} is zero " +
"and being cleaned.", entry.getKey());
// We will clean up unused keys here. An interesting optimization
// might be to have an upper bound on keyspace in callCosts and only
// clean once we pass it.
it.remove();
}
}
// Update the total so that we remain in sync
totalDecayedCallCost.set(totalDecayedCost);
totalRawCallCost.set(totalRawCost);
LOG.debug("After decaying the stored costs, totalDecayedCost: {}, " +
"totalRawCallCost: {}.", totalDecayedCost, totalRawCost);
// Now refresh the cache of scheduling decisions
recomputeScheduleCache();
// Update average response time with decay
updateAverageResponseTime(true);
} catch (Exception ex) {
LOG.error("decayCurrentCosts exception: " +
ExceptionUtils.getStackTrace(ex));
throw ex;
}
}
/**
* Update the scheduleCache to match current conditions in callCosts.
*/
private void recomputeScheduleCache() {
Map nextCache = new HashMap();
for (Map.Entry> entry : callCosts.entrySet()) {
Object id = entry.getKey();
AtomicLong value = entry.getValue().get(0);
long snapshot = value.get();
int computedLevel = computePriorityLevel(snapshot);
nextCache.put(id, computedLevel);
}
// Swap in to activate
scheduleCacheRef.set(Collections.unmodifiableMap(nextCache));
}
/**
* Adjust the stored cost for a given identity.
*
* @param identity the identity of the user whose cost should be adjusted
* @param costDelta the cost to add for the given identity
*/
private void addCost(Object identity, long costDelta) {
// We will increment the cost, or create it if no such cost exists
List cost = this.callCosts.get(identity);
if (cost == null) {
// Create the costs since no such cost exists.
// idx 0 for decayed call cost
// idx 1 for the raw call cost
cost = new ArrayList(2);
cost.add(new AtomicLong(0));
cost.add(new AtomicLong(0));
// Put it in, or get the AtomicInteger that was put in by another thread
List otherCost = callCosts.putIfAbsent(identity, cost);
if (otherCost != null) {
cost = otherCost;
}
}
// Update the total
totalDecayedCallCost.getAndAdd(costDelta);
totalRawCallCost.getAndAdd(costDelta);
// At this point value is guaranteed to be not null. It may however have
// been clobbered from callCosts. Nonetheless, we return what
// we have.
cost.get(1).getAndAdd(costDelta);
cost.get(0).getAndAdd(costDelta);
}
/**
* Given the cost for an identity, compute a scheduling decision.
*
* @param cost the cost for an identity
* @return scheduling decision from 0 to numLevels - 1
*/
private int computePriorityLevel(long cost) {
long totalCallSnapshot = totalDecayedCallCost.get();
double proportion = 0;
if (totalCallSnapshot > 0) {
proportion = (double) cost / totalCallSnapshot;
}
// Start with low priority levels, since they will be most common
for(int i = (numLevels - 1); i > 0; i--) {
if (proportion >= this.thresholds[i - 1]) {
return i; // We've found our level number
}
}
// If we get this far, we're at level 0
return 0;
}
/**
* Returns the priority level for a given identity by first trying the cache,
* then computing it.
* @param identity an object responding to toString and hashCode
* @return integer scheduling decision from 0 to numLevels - 1
*/
private int cachedOrComputedPriorityLevel(Object identity) {
// Try the cache
Map scheduleCache = scheduleCacheRef.get();
if (scheduleCache != null) {
Integer priority = scheduleCache.get(identity);
if (priority != null) {
LOG.debug("Cache priority for: {} with priority: {}", identity,
priority);
return priority;
}
}
// Cache was no good, compute it
List costList = callCosts.get(identity);
long currentCost = costList == null ? 0 : costList.get(0).get();
int priority = computePriorityLevel(currentCost);
LOG.debug("compute priority for {} priority {}", identity, priority);
return priority;
}
/**
* Compute the appropriate priority for a schedulable based on past requests.
* @param obj the schedulable obj to query and remember
* @return the level index which we recommend scheduling in
*/
@Override
public int getPriorityLevel(Schedulable obj) {
// First get the identity
String identity = this.identityProvider.makeIdentity(obj);
if (identity == null) {
// Identity provider did not handle this
identity = DECAYSCHEDULER_UNKNOWN_IDENTITY;
}
return cachedOrComputedPriorityLevel(identity);
}
@Override
public boolean shouldBackOff(Schedulable obj) {
Boolean backOff = false;
if (backOffByResponseTimeEnabled) {
int priorityLevel = obj.getPriorityLevel();
if (LOG.isDebugEnabled()) {
double[] responseTimes = getAverageResponseTime();
LOG.debug("Current Caller: {} Priority: {} ",
obj.getUserGroupInformation().getUserName(),
obj.getPriorityLevel());
for (int i = 0; i < numLevels; i++) {
LOG.debug("Queue: {} responseTime: {} backoffThreshold: {}", i,
responseTimes[i], backOffResponseTimeThresholds[i]);
}
}
// High priority rpc over threshold triggers back off of low priority rpc
for (int i = 0; i < priorityLevel + 1; i++) {
if (responseTimeAvgInLastWindow.get(i) >
backOffResponseTimeThresholds[i]) {
backOff = true;
break;
}
}
}
return backOff;
}
@Override
public void addResponseTime(String callName, Schedulable schedulable,
ProcessingDetails details) {
String user = identityProvider.makeIdentity(schedulable);
long processingCost = costProvider.getCost(details);
addCost(user, processingCost);
int priorityLevel = schedulable.getPriorityLevel();
long queueTime = details.get(Timing.QUEUE, TimeUnit.MILLISECONDS);
long processingTime = details.get(Timing.PROCESSING, TimeUnit.MILLISECONDS);
this.decayRpcSchedulerDetailedMetrics.addQueueTime(
priorityLevel, queueTime);
this.decayRpcSchedulerDetailedMetrics.addProcessingTime(
priorityLevel, processingTime);
responseTimeCountInCurrWindow.getAndIncrement(priorityLevel);
responseTimeTotalInCurrWindow.getAndAdd(priorityLevel,
queueTime+processingTime);
if (LOG.isDebugEnabled()) {
LOG.debug("addResponseTime for call: {} priority: {} queueTime: {} " +
"processingTime: {} ", callName, priorityLevel, queueTime,
processingTime);
}
}
// Update the cached average response time at the end of the decay window
void updateAverageResponseTime(boolean enableDecay) {
for (int i = 0; i < numLevels; i++) {
double averageResponseTime = 0;
long totalResponseTime = responseTimeTotalInCurrWindow.get(i);
long responseTimeCount = responseTimeCountInCurrWindow.get(i);
if (responseTimeCount > 0) {
averageResponseTime = (double) totalResponseTime / responseTimeCount;
}
final double lastAvg = responseTimeAvgInLastWindow.get(i);
if (lastAvg > PRECISION || averageResponseTime > PRECISION) {
if (enableDecay) {
final double decayed = decayFactor * lastAvg + averageResponseTime;
responseTimeAvgInLastWindow.set(i, decayed);
} else {
responseTimeAvgInLastWindow.set(i, averageResponseTime);
}
} else {
responseTimeAvgInLastWindow.set(i, 0);
}
responseTimeCountInLastWindow.set(i, responseTimeCount);
if (LOG.isDebugEnabled()) {
LOG.debug("updateAverageResponseTime queue: {} Average: {} Count: {}",
i, averageResponseTime, responseTimeCount);
}
// Reset for next decay window
responseTimeTotalInCurrWindow.set(i, 0);
responseTimeCountInCurrWindow.set(i, 0);
}
}
// For testing
@VisibleForTesting
double getDecayFactor() {
return decayFactor;
}
@VisibleForTesting
long getDecayPeriodMillis() {
return decayPeriodMillis;
}
@VisibleForTesting
double[] getThresholds() {
return thresholds;
}
@VisibleForTesting
void forceDecay() {
decayCurrentCosts();
}
@VisibleForTesting
Map getCallCostSnapshot() {
HashMap snapshot = new HashMap();
for (Map.Entry> entry : callCosts.entrySet()) {
snapshot.put(entry.getKey(), entry.getValue().get(0).get());
}
return Collections.unmodifiableMap(snapshot);
}
@VisibleForTesting
long getTotalCallSnapshot() {
return totalDecayedCallCost.get();
}
/**
* MetricsProxy is a singleton because we may init multiple schedulers and we
* want to clean up resources when a new scheduler replaces the old one.
*/
public static final class MetricsProxy implements DecayRpcSchedulerMXBean,
MetricsSource {
// One singleton per namespace
private static final HashMap INSTANCES =
new HashMap();
// Weakref for delegate, so we don't retain it forever if it can be GC'd
private WeakReference delegate;
private double[] averageResponseTimeDefault;
private long[] callCountInLastWindowDefault;
private ObjectName decayRpcSchedulerInfoBeanName;
private MetricsProxy(String namespace, int numLevels,
DecayRpcScheduler drs) {
averageResponseTimeDefault = new double[numLevels];
callCountInLastWindowDefault = new long[numLevels];
setDelegate(drs);
decayRpcSchedulerInfoBeanName =
MBeans.register(namespace, "DecayRpcScheduler", this);
this.registerMetrics2Source(namespace);
}
public static synchronized MetricsProxy getInstance(String namespace,
int numLevels, DecayRpcScheduler drs) {
MetricsProxy mp = INSTANCES.get(namespace);
if (mp == null) {
// We must create one
mp = new MetricsProxy(namespace, numLevels, drs);
INSTANCES.put(namespace, mp);
} else if (drs != mp.delegate.get()){
// in case of delegate is reclaimed, we should set it again
mp.setDelegate(drs);
}
return mp;
}
public static synchronized void removeInstance(String namespace) {
MetricsProxy.INSTANCES.remove(namespace);
}
public void setDelegate(DecayRpcScheduler obj) {
this.delegate = new WeakReference(obj);
}
void registerMetrics2Source(String namespace) {
final String name = "DecayRpcSchedulerMetrics2." + namespace;
DefaultMetricsSystem.instance().register(name, name, this);
}
void unregisterSource(String namespace) {
final String name = "DecayRpcSchedulerMetrics2." + namespace;
DefaultMetricsSystem.instance().unregisterSource(name);
if (decayRpcSchedulerInfoBeanName != null) {
MBeans.unregister(decayRpcSchedulerInfoBeanName);
}
}
@Override
public String getSchedulingDecisionSummary() {
DecayRpcScheduler scheduler = delegate.get();
if (scheduler == null) {
return "No Active Scheduler";
} else {
return scheduler.getSchedulingDecisionSummary();
}
}
@Override
public String getCallVolumeSummary() {
DecayRpcScheduler scheduler = delegate.get();
if (scheduler == null) {
return "No Active Scheduler";
} else {
return scheduler.getCallVolumeSummary();
}
}
@Override
public int getUniqueIdentityCount() {
DecayRpcScheduler scheduler = delegate.get();
if (scheduler == null) {
return -1;
} else {
return scheduler.getUniqueIdentityCount();
}
}
@Override
public long getTotalCallVolume() {
DecayRpcScheduler scheduler = delegate.get();
if (scheduler == null) {
return -1;
} else {
return scheduler.getTotalCallVolume();
}
}
@Override
public double[] getAverageResponseTime() {
DecayRpcScheduler scheduler = delegate.get();
if (scheduler == null) {
return averageResponseTimeDefault;
} else {
return scheduler.getAverageResponseTime();
}
}
public long[] getResponseTimeCountInLastWindow() {
DecayRpcScheduler scheduler = delegate.get();
if (scheduler == null) {
return callCountInLastWindowDefault;
} else {
return scheduler.getResponseTimeCountInLastWindow();
}
}
@Override
public void getMetrics(MetricsCollector collector, boolean all) {
DecayRpcScheduler scheduler = delegate.get();
if (scheduler != null) {
scheduler.getMetrics(collector, all);
}
}
}
public int getUniqueIdentityCount() {
return callCosts.size();
}
public long getTotalCallVolume() {
return totalDecayedCallCost.get();
}
public long getTotalRawCallVolume() {
return totalRawCallCost.get();
}
public long[] getResponseTimeCountInLastWindow() {
long[] ret = new long[responseTimeCountInLastWindow.length()];
for (int i = 0; i < responseTimeCountInLastWindow.length(); i++) {
ret[i] = responseTimeCountInLastWindow.get(i);
}
return ret;
}
@Override
public double[] getAverageResponseTime() {
double[] ret = new double[responseTimeAvgInLastWindow.length()];
for (int i = 0; i < responseTimeAvgInLastWindow.length(); i++) {
ret[i] = responseTimeAvgInLastWindow.get(i);
}
return ret;
}
@Override
public void getMetrics(MetricsCollector collector, boolean all) {
// Metrics2 interface to act as a Metric source
try {
MetricsRecordBuilder rb = collector.addRecord(getClass().getName())
.setContext(namespace);
addDecayedCallVolume(rb);
addUniqueIdentityCount(rb);
addTopNCallerSummary(rb);
addAvgResponseTimePerPriority(rb);
addCallVolumePerPriority(rb);
addRawCallVolume(rb);
} catch (Exception e) {
LOG.warn("Exception thrown while metric collection. Exception : "
+ e.getMessage());
}
}
// Key: UniqueCallers
private void addUniqueIdentityCount(MetricsRecordBuilder rb) {
rb.addCounter(Interns.info("UniqueCallers", "Total unique callers"),
getUniqueIdentityCount());
}
// Key: DecayedCallVolume
private void addDecayedCallVolume(MetricsRecordBuilder rb) {
rb.addCounter(Interns.info("DecayedCallVolume", "Decayed Total " +
"incoming Call Volume"), getTotalCallVolume());
}
private void addRawCallVolume(MetricsRecordBuilder rb) {
rb.addCounter(Interns.info("CallVolume", "Raw Total " +
"incoming Call Volume"), getTotalRawCallVolume());
}
// Key: Priority.0.CompletedCallVolume
private void addCallVolumePerPriority(MetricsRecordBuilder rb) {
for (int i = 0; i < responseTimeCountInLastWindow.length(); i++) {
rb.addGauge(Interns.info("Priority." + i + ".CompletedCallVolume",
"Completed Call volume " +
"of priority "+ i), responseTimeCountInLastWindow.get(i));
}
}
// Key: Priority.0.AvgResponseTime
private void addAvgResponseTimePerPriority(MetricsRecordBuilder rb) {
for (int i = 0; i < responseTimeAvgInLastWindow.length(); i++) {
rb.addGauge(Interns.info("Priority." + i + ".AvgResponseTime", "Average" +
" response time of priority " + i),
responseTimeAvgInLastWindow.get(i));
}
}
// Key: Caller(xyz).Volume and Caller(xyz).Priority
private void addTopNCallerSummary(MetricsRecordBuilder rb) {
TopN topNCallers = getTopCallers(topUsersCount);
Map decisions = scheduleCacheRef.get();
final int actualCallerCount = topNCallers.size();
for (int i = 0; i < actualCallerCount; i++) {
NameValuePair entry = topNCallers.poll();
String topCaller = "Caller(" + entry.getName() + ")";
String topCallerVolume = topCaller + ".Volume";
String topCallerPriority = topCaller + ".Priority";
rb.addCounter(Interns.info(topCallerVolume, topCallerVolume),
entry.getValue());
Integer priority = decisions.get(entry.getName());
if (priority != null) {
rb.addCounter(Interns.info(topCallerPriority, topCallerPriority),
priority);
}
}
}
// Get the top N callers' raw call cost and scheduler decision
private TopN getTopCallers(int n) {
TopN topNCallers = new TopN(n);
Iterator>> it =
callCosts.entrySet().iterator();
while (it.hasNext()) {
Map.Entry> entry = it.next();
String caller = entry.getKey().toString();
Long cost = entry.getValue().get(1).get();
if (cost > 0) {
topNCallers.offer(new NameValuePair(caller, cost));
}
}
return topNCallers;
}
public String getSchedulingDecisionSummary() {
Map decisions = scheduleCacheRef.get();
if (decisions == null) {
return "{}";
} else {
try {
return WRITER.writeValueAsString(decisions);
} catch (Exception e) {
return "Error: " + e.getMessage();
}
}
}
public String getCallVolumeSummary() {
try {
return WRITER.writeValueAsString(getDecayedCallCosts());
} catch (Exception e) {
return "Error: " + e.getMessage();
}
}
private Map getDecayedCallCosts() {
Map decayedCallCosts = new HashMap<>(callCosts.size());
Iterator>> it =
callCosts.entrySet().iterator();
while (it.hasNext()) {
Map.Entry> entry = it.next();
Object user = entry.getKey();
Long decayedCost = entry.getValue().get(0).get();
if (decayedCost > 0) {
decayedCallCosts.put(user, decayedCost);
}
}
return decayedCallCosts;
}
@VisibleForTesting
public DecayRpcSchedulerDetailedMetrics
getDecayRpcSchedulerDetailedMetrics() {
return decayRpcSchedulerDetailedMetrics;
}
@Override
public void stop() {
metricsProxy.unregisterSource(namespace);
MetricsProxy.removeInstance(namespace);
decayRpcSchedulerDetailedMetrics.shutdown();
}
}