org.cloudera.htrace.impl.ZipkinSpanReceiver Maven / Gradle / Ivy
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* 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.cloudera.htrace.impl;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import com.twitter.zipkin.gen.LogEntry;
import com.twitter.zipkin.gen.Scribe;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.protocol.TProtocolFactory;
import org.apache.thrift.transport.TFramedTransport;
import org.apache.thrift.transport.TIOStreamTransport;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;
import org.apache.thrift.transport.TTransportException;
import org.cloudera.htrace.HTraceConfiguration;
import org.cloudera.htrace.Span;
import org.cloudera.htrace.SpanReceiver;
import org.cloudera.htrace.zipkin.HTraceToZipkinConverter;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Zipkin is an open source tracing library. This span receiver acts as a bridge between HTrace and
* Zipkin, that converts HTrace Span objects into Zipkin Span objects.
*
* HTrace spans are queued into a blocking queue. From there background worker threads will
* batch the spans together and then send them through to a Zipkin collector.
*/
public class ZipkinSpanReceiver implements SpanReceiver {
private static final Log LOG = LogFactory.getLog(ZipkinSpanReceiver.class);
/**
* Default hostname to fall back on.
*/
private static final String DEFAULT_COLLECTOR_HOSTNAME = "localhost";
/**
* Default collector port.
*/
private static final int DEFAULT_COLLECTOR_PORT = 9410; // trace collector default port.
/**
* this is used to tell scribe that the entries are for zipkin..
*/
private static final String CATEGORY = "zipkin";
/**
* Whether the service which is traced is in client or a server mode. It is used while creating
* the Endpoint.
*/
private static final boolean DEFAULT_IN_CLIENT_MODE = false;
/**
* How long this receiver will try and wait for all threads to shutdown.
*/
private static final int SHUTDOWN_TIMEOUT = 30;
/**
* How many spans this receiver will try and send in one batch.
*/
private static final int MAX_SPAN_BATCH_SIZE = 100;
/**
* How many errors in a row before we start dropping traces on the floor.
*/
private static final int MAX_ERRORS = 10;
/**
* The queue that will get all HTrace spans that are to be sent.
*/
private final BlockingQueue queue;
/**
* Factory used to encode a Zipkin Span to bytes.
*/
private final TProtocolFactory protocolFactory;
/**
* Boolean used to signal that the threads should end.
*/
private final AtomicBoolean running = new AtomicBoolean(true);
/**
* The thread factory used to create new ExecutorService.
*
* This will be the same factory for the lifetime of this object so that
* no thread names will ever be duplicated.
*/
private final ThreadFactory tf;
////////////////////
/// Variables that will change on each call to configure()
///////////////////
private HTraceToZipkinConverter converter;
private ExecutorService service;
private HTraceConfiguration conf;
private String collectorHostname;
private int collectorPort;
public ZipkinSpanReceiver() {
this.queue = new ArrayBlockingQueue(1000);
this.protocolFactory = new TBinaryProtocol.Factory();
tf = new ThreadFactoryBuilder().setDaemon(true)
.setNameFormat("zipkinSpanReceiver-%d")
.build();
}
@Override
public void configure(HTraceConfiguration conf) {
this.conf = conf;
this.collectorHostname = conf.get("zipkin.collector-hostname",
DEFAULT_COLLECTOR_HOSTNAME);
this.collectorPort = conf.getInt("zipkin.collector-port",
DEFAULT_COLLECTOR_PORT);
// initialize the endpoint. This endpoint is used while writing the Span.
initConverter();
int numThreads = conf.getInt("zipkin.num-threads", 1);
// If there are already threads runnnig tear them down.
if (this.service != null) {
this.service.shutdownNow();
this.service = null;
}
this.service = Executors.newFixedThreadPool(numThreads, tf);
for (int i = 0; i < numThreads; i++) {
this.service.submit(new WriteSpanRunnable());
}
}
/**
* Set up the HTrace to Zipkin converter.
*/
private void initConverter() {
InetAddress tracedServiceHostname = null;
// Try and get the hostname. If it's not configured try and get the local hostname.
try {
String host = conf.get("zipkin.traced-service-hostname",
InetAddress.getLocalHost().getHostAddress());
tracedServiceHostname = InetAddress.getByName(host);
} catch (UnknownHostException e) {
LOG.error("Couldn't get the localHost address", e);
}
short tracedServicePort = (short) conf.getInt("zipkin.traced-service-port", -1);
byte[] address = tracedServiceHostname != null
? tracedServiceHostname.getAddress() : DEFAULT_COLLECTOR_HOSTNAME.getBytes();
int ipv4 = ByteBuffer.wrap(address).getInt();
this.converter = new HTraceToZipkinConverter(ipv4, tracedServicePort);
}
private class WriteSpanRunnable implements Runnable {
/**
* scribe client to push zipkin spans
*/
private Scribe.Client scribeClient = null;
private final ByteArrayOutputStream baos;
private final TProtocol streamProtocol;
public WriteSpanRunnable() {
baos = new ByteArrayOutputStream();
streamProtocol = protocolFactory.getProtocol(new TIOStreamTransport(baos));
}
/**
* This runnable converts a HTrace span to a Zipkin span and sends it across the zipkin
* collector as a thrift object. The scribe client which is used for rpc writes a list of
* LogEntry objects, so the span objects are first transformed into LogEntry objects before
* sending to the zipkin-collector.
*
* Here is a little ascii art which shows the above transformation:
*
* +------------+ +------------+ +------------+ +-----------------+
* | HTrace Span|-->|Zipkin Span |-->| (LogEntry) | ===========> | Zipkin Collector|
* +------------+ +------------+ +------------+ (Scribe rpc) +-----------------+
*
*/
@Override
public void run() {
List dequeuedSpans = new ArrayList(MAX_SPAN_BATCH_SIZE);
long errorCount = 0;
while (running.get() || queue.size() > 0) {
Span firstSpan = null;
try {
// Block for up to a second. to try and get a span.
// We only block for a little bit in order to notice if the running value has changed
firstSpan = queue.poll(1, TimeUnit.SECONDS);
// If the poll was successful then it's possible that there
// will be other spans to get. Try and get them.
if (firstSpan != null) {
// Add the first one that we got
dequeuedSpans.add(firstSpan);
// Try and get up to 100 queues
queue.drainTo(dequeuedSpans, MAX_SPAN_BATCH_SIZE - 1);
}
} catch (InterruptedException ie) {
// Ignored.
}
if (dequeuedSpans.isEmpty()) continue;
// If this is the first time through or there was an error re-connect
if (scribeClient == null) {
startClient();
}
// Create a new list every time through so that the list doesn't change underneath
// thrift as it's sending.
List entries = new ArrayList(dequeuedSpans.size());
try {
// Convert every de-queued span
for (Span htraceSpan : dequeuedSpans) {
// convert the HTrace span to Zipkin span
com.twitter.zipkin.gen.Span zipkinSpan = converter.convert(htraceSpan);
// Clear any old data.
baos.reset();
// Write the span to a BAOS
zipkinSpan.write(streamProtocol);
// Do Base64 encoding and put the string into a log entry.
LogEntry logEntry =
new LogEntry(CATEGORY, Base64.encodeBase64String(baos.toByteArray()));
entries.add(logEntry);
}
// Send the entries
scribeClient.Log(entries);
// clear the list for the next time through.
dequeuedSpans.clear();
// reset the error counter.
errorCount = 0;
} catch (Exception e) {
LOG.error("Error when writing to the zipkin collector: " +
collectorHostname + ":" + collectorPort);
errorCount += 1;
// If there have been ten errors in a row start dropping things.
if (errorCount < MAX_ERRORS) {
dequeuedSpans.addAll(dequeuedSpans);
}
closeClient();
try {
// Since there was an error sleep just a little bit to try and allow the
// zipkin collector some time to recover.
Thread.sleep(500);
} catch (InterruptedException e1) {
// Ignored
}
}
}
closeClient();
}
/**
* Close out the connection.
*/
private void closeClient() {
// close out the transport.
if (scribeClient != null) {
scribeClient.getInputProtocol().getTransport().close();
scribeClient = null;
}
}
/**
* Re-connect to Zipkin.
*/
private void startClient() {
if (this.scribeClient == null) {
TTransport transport = new TFramedTransport(new TSocket(collectorHostname, collectorPort));
try {
transport.open();
} catch (TTransportException e) {
e.printStackTrace();
}
TProtocol protocol = protocolFactory.getProtocol(transport);
this.scribeClient = new Scribe.Client(protocol);
}
}
}
/**
* Close the receiver.
*
* This tries to shut
*
* @throws IOException
*/
@Override
public void close() throws IOException {
running.set(false);
service.shutdown();
try {
if (!service.awaitTermination(SHUTDOWN_TIMEOUT, TimeUnit.SECONDS)) {
LOG.error("Was not able to process all remaining spans to write upon closing in: " +
SHUTDOWN_TIMEOUT + " " + TimeUnit.SECONDS + ". There could be un-sent spans still left." +
" They have been dropped.");
}
} catch (InterruptedException e1) {
LOG.warn("Thread interrupted when terminating executor.", e1);
}
}
@Override
public void receiveSpan(Span span) {
if (running.get()) {
try {
this.queue.add(span);
} catch (IllegalStateException e) {
LOG.error("Error trying to append span (" + span.getDescription() + ") to the queue."
+ " Blocking Queue was full.");
}
}
}
}