问题
I use CQ v5.16.11 (with openjdk 11) to save data with daily roll cycles. The process runs non-stop from Sun to Fri so I have 5 cq4 files per week. I ran the process for 1.5 weeks and have 8 files (3 for 1st and 5 for 2nd week).
So the files that I have are:
20181003.cq4 cycle=17807,
20181004.cq4 cycle=17808,
20181005.cq4 cycle=17809,
20181007.cq4 cycle=17811,
20181008.cq4 cycle=17812,
20181009.cq4 cycle=17813,
20181010.cq4 cycle=17814,
20181011.cq4 cycle=17815,
Note the missing file for 20181006.cq4 (cycle=17810) as the process does not run on Saturday.
I use this code to read data:
tailer.toEnd();
lastTailerIndex = tailer.index();
tailer.toStart();
while (tailer.index() <= lastTailerIndex) {
// read data
if (tailer.readBytes(data) {
/// do something with data bytes
}
if (tailer.index() == lastTailerIndex) {
break;
}
}
This correctly reads the 1st week data but does not read the 2nd week data as it does not auto-roll to next cycle.
Any idea why this is happening or how to fix this?
The issue is similar to this which was for an older version
- Reading message from chronicle queue does not move the current index to the next cycle automatically
- I have created a single queue with daily rolling
Logs:
2018-10-12 12:41:15,784 DEBUG [main] net.openhft.chronicle.bytes.MappedFile - Allocation of 0 chunk in /site/data/metadata.cq4t took 19.237 ms.
2018-10-12 12:41:15,876 DEBUG [main] net.openhft.chronicle.bytes.MappedFile - Allocation of 0 chunk in /site/data/20181011.cq4 took 0.063 ms.
2018-10-12 12:41:15,881 DEBUG [main] net.openhft.chronicle.queue.impl.single.PretoucherState - /site/data/20181011.cq4 - Reset pretoucher to pos 4835096 as the underlying MappedBytes changed.
2018-10-12 12:41:15,887 DEBUG [main] net.openhft.chronicle.bytes.MappedFile - Allocation of 0 chunk in /site/data/20181003.cq4 took 0.065 ms.
2018-10-12 12:41:15,995 DEBUG [main] net.openhft.chronicle.bytes.MappedFile - Allocation of 0 chunk in /site/data/20181011.cq4 took 0.082 ms.
2018-10-12 12:41:15,996 DEBUG [main] net.openhft.chronicle.queue.impl.single.SingleChronicleQueueBuilder - File released /site/data/20181003.cq4
2018-10-12 12:41:15,997 DEBUG [main] net.openhft.chronicle.queue.impl.single.SingleChronicleQueueBuilder - File released /site/data/20181011.cq4
2018-10-12 12:41:16,418 DEBUG [main] net.openhft.chronicle.bytes.MappedFile - Allocation of 0 chunk in /site/data/20181004.cq4 took 0.112 ms.
2018-10-12 12:41:16,418 DEBUG [main] net.openhft.chronicle.queue.impl.single.SingleChronicleQueueBuilder - File released /site/data/20181003.cq4
2018-10-12 12:41:16,813 DEBUG [main] net.openhft.chronicle.bytes.MappedFile - Allocation of 0 chunk in /site/data/20181005.cq4 took 0.084 ms.
2018-10-12 12:41:16,813 DEBUG [main] net.openhft.chronicle.queue.impl.single.SingleChronicleQueueBuilder - File released /site/data/20181004.cq4
[Edit 1]:
The same thing happened on this last weekend, i.e., as expected no new file for Oct 13. Now I have files from Oct 7th to Oct 15th (with missing Oct 13th file). If I do tailer.toStart(); while(tailer.readBytes() { ...} it only reads files from Oct7th till Oct 12th and does not read Oct 14th and 15th.
[Edit 2]: Replicated the issue as below Chronicle-Queue/issues/537
- Setup / Libs: jvm openjdk 11, Ubuntu 16.04, openhft.affinity/3.1.9, chronicle-map/3.16.0, chronicle-queue/5.16.11, chronicle-bytes/1.16.23, chronicle-core/1.16.20, chronicle-wire/1.16.16, chronicle-threads/1.16.3, jna/4.4.0
- Steps:
- Start WriterProcess - let it finish.
- Start ReaderProcess - see the 5 print statements.
- Stop ReaderProcess
- Wait for some time - 10 mins.
- Start WriterProcess again - let it finish or keep running this process.
- Start ReaderProcess - it prints only the first 5 print statements and nothing prints after this. Even if the WriterProcess is running/writing to queue the tailer in this process does not move forward.
public class WriterProcess {
public static void main(String[] args) throws InterruptedException {
final String dir = "/tmp/demo/";
final LocalTime localTime = LocalTime.of(17, 0);
final ZoneId zoneID = ZoneId.of("America/New_York");
final ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(2);
final SingleChronicleQueue queue = SingleChronicleQueueBuilder.binary(dir)
.blockSize((long) Math.pow(2, 23))
.rollCycle(RollCycles.MINUTELY)
.rollTime(localTime, zoneID)
.build();
final ExcerptAppender appender = queue.acquireAppender();
// pre touch
scheduledExecutorService.scheduleAtFixedRate(appender::pretouch,0,30, TimeUnit.SECONDS);
// write data
System.out.println("writing data ...");
writeData(appender, 5);
// close queue
System.out.println("shutting down now ...");
queue.close();
scheduledExecutorService.shutdown();
scheduledExecutorService.awaitTermination(1, TimeUnit.SECONDS);
}
public static void writeData(ExcerptAppender appender, int count) {
int ctr = 0;
String dateStr;
Date date = new Date();
while (true) {
dateStr = date.toString();
appender.writeText("["+ctr+"] Written " + dateStr);
System.out.println("["+ctr+"] Written " + dateStr);
ctr++;
if (ctr >= count) {
break;
}
try {
Thread.sleep(65_000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
public class ReaderProcess {
public static void main(String[] args) {
final String dir = "/tmp/demo/";
final LocalTime localTime = LocalTime.of(17, 0);
final ZoneId zoneID = ZoneId.of("America/New_York");
final SingleChronicleQueue queue = SingleChronicleQueueBuilder.binary(dir)
.blockSize((long) Math.pow(2, 23))
.rollCycle(RollCycles.MINUTELY)
.rollTime(localTime, zoneID)
.build();
final ExcerptTailer tailer = queue.createTailer();
tailer.toStart();
// read data
System.out.println("reading data ...");
readData(tailer, 25);
// close
System.out.println("shutting down now ...");
queue.close();
}
public static void readData(ExcerptTailer tailer, int count) {
int ctr = 0;
Bytes data = Bytes.allocateDirect(new byte[500]);
while (true) {
if (tailer.readBytes(data)) {
System.out.println("["+ctr+"] Read {"+ data + "}");
ctr++;
if (ctr >= count) {
break;
}
}
}
}
}
回答1:
I have written a slightly simpler version which works with chronicle-bom 2.17 and the versions it uses. The biggest change I made was to clear the Bytes data before reading otherwise it only appends so as to not overwrite anything.
import net.openhft.chronicle.bytes.Bytes;
import net.openhft.chronicle.core.OS;
import net.openhft.chronicle.queue.ExcerptAppender;
import net.openhft.chronicle.queue.ExcerptTailer;
import net.openhft.chronicle.queue.RollCycles;
import net.openhft.chronicle.queue.impl.single.SingleChronicleQueue;
import net.openhft.chronicle.queue.impl.single.SingleChronicleQueueBuilder;
import java.time.LocalDateTime;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
public class WriterProcess {
static final String dir = OS.TMP + "/demo-" + System.nanoTime() + "/";
public static void main(String[] args) throws InterruptedException {
final ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(2);
final SingleChronicleQueue queue = SingleChronicleQueueBuilder.binary(dir)
.testBlockSize()
.rollCycle(RollCycles.TEST_SECONDLY)
.build();
final ExcerptAppender appender = queue.acquireAppender();
// pre touch
scheduledExecutorService.scheduleAtFixedRate(appender::pretouch, 3, 30, TimeUnit.SECONDS);
new Thread(ReaderProcess::main).start();
// write data
System.out.println("writing data ...");
writeData(appender, 100);
// close queue
System.out.println("shutting down now ...");
queue.close();
scheduledExecutorService.shutdown();
scheduledExecutorService.awaitTermination(1, TimeUnit.SECONDS);
}
public static void writeData(ExcerptAppender appender, int count) {
int ctr = 0;
while (true) {
LocalDateTime date = LocalDateTime.now();
appender.writeText("[" + ctr + "] Written " + date);
System.out.println("[" + ctr + "] Written " + date);
ctr++;
if (ctr >= count) {
break;
}
try {
Thread.sleep(2_200);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
class ReaderProcess {
public static void main(String... args) {
final String dir = WriterProcess.dir;
final SingleChronicleQueue queue = SingleChronicleQueueBuilder.binary(dir)
.testBlockSize()
.rollCycle(RollCycles.TEST_SECONDLY)
.build();
final ExcerptTailer tailer = queue.createTailer();
tailer.toStart();
// read data
System.out.println("reading data ...");
readData(tailer, 100);
// close
System.out.println("shutting down now ...");
queue.close();
}
public static void readData(ExcerptTailer tailer, int count) {
int ctr = 0;
Bytes data = Bytes.allocateDirect(64);
while (true) {
data.clear();
if (tailer.readBytes(data)) {
System.out.println("[" + ctr + "] Read {" + data + "}");
ctr++;
if (ctr >= count) {
break;
}
}
}
}
}
来源：https://stackoverflow.com/questions/52783626/reading-messages-in-chronicle-queue-tailer-v5-16-11-does-not-auto-move-the-ind