I am investigating Chronicle Map as a potential replacement of Redis - with concurrency in mind. In our architecture we would be looking to replace a "large" Redis instance that currently has multiple clients connecting to it causing latency pileups due to Redis' blocking nature.

The issue is that we need to make requests in random batches of ~1000. With Redis we are able to make a single request via a Lua script (or multi-get / multi-set commands) and receive a single response. In the documentation on Chronicle Maps stateless client I see that the remote calls are blocking and can be made only one key at a time, so for us the solution is not obvious.

While I am considering passing off each individual key task to a threadpool running X blocking threads at a time, I wonder if there might be a better solution that could take advantage of doing RPC in batches and perhaps work asynchronously. As I do not see this available currently, my questions are whether this is an enhancement you might consider or if you could perhaps point me to if/how we could write our own solution for doing this - which we'd be open to contributing back...

Hello,

I am running some tests for ChronicleSet of strings that is supposed to be used concurrent by 5 threads and with the following code I am getting "net.openhft.chronicle.hash.locks.IllegalInterProcessLockStateException: Must not acquire update lock, while read lock is already held by this thread"

Here the code snippet:

public class TestChronicleSet {

public static <H extends ChronicleHash<K,?>,  B extends ChronicleHashBuilder<K, H, B>, K> H init(B builder, int entrySize, int averageKeySize, String fileName) {

    String tmp = System.getProperty("java.io.tmpdir");
    String pathname = tmp + "/" + fileName;
    File file = new File(pathname);
    try {
        H result = builder.entries(entrySize).averageKeySize(averageKeySize).createPersistedTo(file);
        return result;
    } catch (IOException ioe) {
        throw new RuntimeException(ioe);
    }
}

public synchronized static <A> ChronicleSet<A> initSet(Class<A> entryClass, int entrySize, int averageKeySize, String fileName) {
    return init(ChronicleSetBuilder.of(entryClass), entrySize, averageKeySize, fileName);
}

public static void main(String[] args) {
    ChronicleSet<String> set = initSet(String.class, 1_000_000, 30, "stringSet.dat");
    ExecutorService executor = Executors.newFixedThreadPool(5);
    for (int i = 0; i < 10; i++) {
        Runnable worker = new WorkerThread(set);
        executor.execute(worker);
    }
    executor.shutdown();
    while (!executor.isTerminated()) {

    }
    System.out.println("Finished all threads");


}

public static class WorkerThread implements Runnable {
    private final ChronicleSet<String> set;
    public WorkerThread(ChronicleSet<String> set){
        this.set = set;
    }

    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName()+" Start. Command = " + set.size());
        processCommand();
        System.out.println(Thread.currentThread().getName()+" End.");
    }

    private void processCommand() {
        Set<String> nomenclatures = new HashSet<>();
        for(int i = 0; i < 10; i++) {
            String nomenclature = "#############################" + i;
            nomenclatures.add(nomenclature);

        }

        set.addAll(nomenclatures);


        Set<String> strings = CollectionUtil.randomSubset(nomenclatures, new Random());

        set.addAll(strings);


        Set<String> toRemove = new HashSet<>();
        Random generator = new Random();
        for (int j = 0; j < 3; j++) {
            int i = generator.nextInt(10);
            String nomenclature = "#############################" + i;
            toRemove.add(nomenclature);
        }
        set.removeAll(toRemove);

        for (String s : set) {
            System.out.println(s);
        }

        strings = CollectionUtil.randomSubset(nomenclatures, new Random());

        set.addAll(strings);

        for (String s : set) {
            System.out.println(s);
        }
    }

}

}

Since ChronicleSet is almost the same as ChronicleMap I expect that it will be thread safe. Can you please have a look at the example code and let me know whether it is a bug into ChronicleSet implementation or I am supposed to synchronize the code for addAll/removeAll operations on the application side?

Thanks, Radoslav

Regarding this commit: https://github.com/OpenHFT/Chronicle-Map/commit/79c7701a52058361150f7d2e7139cbd0d4211a9f, @RobAustin there was a reason why the code was written the way it was - it's that during relocation a different value alignment might be required, therefore a different number of chunks might be needed.

I'm using 2.1.10 and trying to change the entrySize appropriately but apparently this was removed at some point. Documenation still refers to this function (https://github.com/OpenHFT/Chronicle-Map#dont-forget-to-set-the-entrysize) and the exception that I receive also states this as a solution.

java.lang.IllegalStateException: We try to figure out size of objects in serialized form, but it exceeds 16777216 bytes. We assume this is a error and throw exception at this point. If you really want larger keys/values, use ChronicleMapBuilder.keySize(int)/valueSize(int)/entrySize(int) configurations

What is the recommended way to set the entry size on current releases?

Chronicle-Map is currently not working with upcoming JRE 9. So far, I've identified following problems (tested with 9+179):

• ByteBufferDataAccess is using sun.nio.ch.DirectBuffer which won't be accessible anymore. As MappedByteBuffer is the only ByteBuffer which is a DirectBuffer, this should be easy to resolve by changing getData to:

public Data<ByteBuffer> getData(@NotNull ByteBuffer instance) {
    bb = instance;
    if (instance instanceof MappedByteBuffer) {
        nativeBytesStore.init(instance, false);
        bytesStore = nativeBytesStore;
    } else {
        heapBytesStore.init(instance);
        bytesStore = heapBytesStore;
    }
    return this;
}

• VanillaChronicleHash is using sun.misc.Cleaner which won't be available anymore.

 <dependency>
     <groupId>net.openhft</groupId>
     <artifactId>chronicle-map</artifactId>
     <version>1.0.2</version>
   </dependency>

Using JDK 1.7

From the 1.8 in the tools, can I assume this requires JDK 1.8?

Thanks?

Hi, taking a simple working code with sun jdk 1.8 and compiling/running with OpenJDK10, errors are thrown. Here is stack trace:

net.openhft.chronicle.core.Jvm: Unable to determine max direct memory WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by net.openhft.chronicle.core.Jvm (file:/xxxxxxxx/net/openhft/chronicle-core/1.15.1/chronicle-core-1.15.1.jar) to field java.nio.Bits.reservedMemory WARNING: Please consider reporting this to the maintainers of net.openhft.chronicle.core.Jvm WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release Exception in thread "main" java.lang.IllegalStateException: Key size in serialized form must be configured in ChronicleMap, at least approximately. Use builder.averageKey()/.constantKeySizeBySample()/.averageKeySize() methods to configure the size at net.openhft.chronicle.map.ChronicleMapBuilder.preMapConstruction(ChronicleMapBuilder.java:1865) at net.openhft.chronicle.map.ChronicleMapBuilder.preMapConstruction(ChronicleMapBuilder.java:1848) at net.openhft.chronicle.map.ChronicleMapBuilder.newMap(ChronicleMapBuilder.java:1832) at net.openhft.chronicle.map.ChronicleMapBuilder.lambda$createWithFile$3(ChronicleMapBuilder.java:1633) at net.openhft.chronicle.map.ChronicleMapBuilder.lambda$fileLockedIO$1(ChronicleMapBuilder.java:257) at java.base/java.util.concurrent.ConcurrentHashMap.compute(ConcurrentHashMap.java:1922) at net.openhft.chronicle.map.ChronicleMapBuilder.fileLockedIO(ChronicleMapBuilder.java:254) at net.openhft.chronicle.map.ChronicleMapBuilder.createWithFile(ChronicleMapBuilder.java:1631) at net.openhft.chronicle.map.ChronicleMapBuilder.createPersistedTo(ChronicleMapBuilder.java:1549) at net.openhft.chronicle.map.ChronicleMapBuilder.createOrRecoverPersistedTo(ChronicleMapBuilder.java:1571) at net.openhft.chronicle.map.ChronicleMapBuilder.createOrRecoverPersistedTo(ChronicleMapBuilder.java:1560) at net.openhft.chronicle.map.ChronicleMapBuilder.createOrRecoverPersistedTo(ChronicleMapBuilder.java:1554)

Code is

ChronicleMap<LongValue, int[]> map = null; try { map = ChronicleMapBuilder .of(LongValue.class, int[].class) .name("map") .entries(HOW_MANY) .averageValue(new int[VALUE_LENGTH]) .createOrRecoverPersistedTo(path);

I am seeing the following error: net.openhft.chronicle.core.io.IORuntimeException: java.lang.ClassNotFoundException: [Ljava/lang/Long at net.openhft.chronicle.wire.TextWire$TextValueIn.typeLiteral(TextWire.java:2932) at net.openhft.chronicle.map.VanillaChronicleMap.readMarshallableFields(VanillaChronicleMap.java:123) at net.openhft.chronicle.hash.impl.VanillaChronicleHash.readMarshallable(VanillaChronicleHash.java:243) at net.openhft.chronicle.wire.SerializationStrategies$1.readUsing(SerializationStrategies.java:43) at net.openhft.chronicle.wire.TextWire$TextValueIn.marshallable(TextWire.java:2975) at net.openhft.chronicle.wire.Wires.objectMap(Wires.java:442) at net.openhft.chronicle.wire.Wires.object0(Wires.java:495) at net.openhft.chronicle.wire.ValueIn.object(ValueIn.java:587) at net.openhft.chronicle.wire.TextWire$TextValueIn.objectWithInferredType0(TextWire.java:3269) at net.openhft.chronicle.wire.TextWire$TextValueIn.objectWithInferredType(TextWire.java:3242) at net.openhft.chronicle.wire.TextWire$TextValueIn.typedMarshallable(TextWire.java:3037) at net.openhft.chronicle.map.ChronicleMapBuilder.openWithExistingFile(ChronicleMapBuilder.java:1767) at net.openhft.chronicle.map.ChronicleMapBuilder.createWithFile(ChronicleMapBuilder.java:1566) at net.openhft.chronicle.map.ChronicleMapBuilder.createPersistedTo(ChronicleMapBuilder.java:1495)

when I run the code: `File file = new File("d:/temp/_" + System.nanoTime()); //write ChronicleMap<Long, Long[]> writeMap = ChronicleMap .of(Long.class, Long[].class) .entries(1_000) .averageValue(new Long[150]) .createPersistedTo(file); Long a[]={2L}; writeMap.put(1L,a);

//read
ChronicleMap<Long, Long[]> readMap = ChronicleMapBuilder.of(Long.class, Long[].class) .averageValue(new Long[150]) .createPersistedTo(file);
Long b[] = readMap.get(1L);`

I ran"System.out.println(Long[].class.getName());" and got "[Ljava.lang.Long;". But the error log is saying"net.openhft.chronicle.core.io.IORuntimeException: java.lang.ClassNotFoundException: [Ljava/lang/Long", which is missing ";" in the end of class name. I tried step throw and found in "BytesInternal.java" line 1769, tester.isStopChar(c) returns true when c==59(;). which makes it cant return a class name with ";".

First of all I really like openHFT, thanks for sharing!!

I try to follow the example using the off heap direct access to primitives ( https://github.com/OpenHFT/Chronicle-Map#off-heap-storage-and-how-using-a-proxy-object-can-improve-performance ). Sadly this seems not to work with arrays. But this would be a very cool thing. Even better would be if we could act on an specific index of an array directly off heap!

See this quick and dirty example: Hello World

public class HftTest {
    public static void main(String[] args) {
        ChronicleMap proxyMap = ChronicleMapBuilder.of(Integer.class,
                IArray.class).create();


        TestArray ta1 = new TestArray();
        ta1.setdata(new double[]{1, 2, 3, 4, 5});

        TestArray ta2 = new TestArray();
        ta1.setdata(new double[]{5, 6, 7, 8, 9});

        proxyMap.put(1, ta1);
        proxyMap.put(2, ta2);

        IArray using = proxyMap.newValueInstance();

        System.out.println(Arrays.toString(proxyMap.getUsing(1, using).getdata()));
        System.out.println(Arrays.toString(proxyMap.getUsing(2, using).getdata()));
    }
}

Interface

public interface IArray extends Serializable {
    double[] getdata();
    void setdata(double[] data);
}

Implementation

public class TestArray implements IArray {
    private double[] data;

    @Override
    public double[] getdata() {
        return data;
    }

    @Override
    public void setdata(double[] data) {
        this.data = data;
    }
}

With all versions later 3.17.8 on Java 11 this message occurs:

WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access using Lookup on net.openhft.chronicle.core.Jvm (file:/Users/TORS/.m2/repository/net/openhft/chronicle-core/2.19.32/chronicle-core-2.19.32.jar) to class java.lang.reflect.AccessibleObject WARNING: Please consider reporting this to the maintainers of net.openhft.chronicle.core.Jvm WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release

I am seeing the following exception from time to time. Not sure what cause this.. It seems like the .dat file is corrupted as problem could be fixed after I regenerated the file. `Caused by: net.openhft.chronicle.hash.locks.InterProcessDeadLockException: ChronicleMap{name=null, file=E:\pva_binary_data_TODAY\secIdSymbol.dat, identityHashCode=1995022532}: Contexts locked on this segment: net.openhft.chronicle.map.impl.CompiledMapIterationContext@38391dde: used, segment 27, local state: UNLOCKED, read lock count: 0, update lock count: 0, write lock count: 0 Current thread contexts: net.openhft.chronicle.map.impl.CompiledMapQueryContext@3924d577: unused net.openhft.chronicle.map.impl.CompiledMapIterationContext@38391dde: used, segment 27, local state: UNLOCKED, read lock count: 0, update lock count: 0, write lock count: 0

at net.openhft.chronicle.map.impl.CompiledMapIterationContext.debugContextsAndLocks(CompiledMapIterationContext.java:1798)
at net.openhft.chronicle.map.impl.CompiledMapIterationContext.debugContextsAndLocksGuarded(CompiledMapIterationContext.java:116)
at net.openhft.chronicle.map.impl.CompiledMapIterationContext$UpdateLock.lock(CompiledMapIterationContext.java:809)
at net.openhft.chronicle.map.impl.CompiledMapIterationContext.forEachSegmentEntryWhile(CompiledMapIterationContext.java:3942)
at net.openhft.chronicle.map.impl.CompiledMapIterationContext.forEachSegmentEntry(CompiledMapIterationContext.java:3948)
at net.openhft.chronicle.map.ChronicleMapIterator.fillEntryBuffer(ChronicleMapIterator.java:61)
at net.openhft.chronicle.map.ChronicleMapIterator.hasNext(ChronicleMapIterator.java:77)
at java.util.Iterator.forEachRemaining(Iterator.java:115)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
at com.pva.common.util.UUIDUtil.reverseGenericeMap(UUIDUtil.java:92)
at com.pva.common.util.UUIDUtil.reverseMap(UUIDUtil.java:100)
at com.pva.algotrading.analysis.service.api.impl.SymbolLookupImpl.loadRevMap(SymbolLookupImpl.java:57)
... 29 more

Caused by: net.openhft.chronicle.hash.locks.InterProcessDeadLockException: Failed to acquire the lock in 60 seconds. Possible reasons:

• The lock was not released by the previous holder. If you use contexts API, for example map.queryContext(key), in a try-with-resources block.

• This Chronicle Map (or Set) instance is persisted to disk, and the previous process (or one of parallel accessing processes) has crashed while holding this lock. In this case you should use ChronicleMapBuilder.recoverPersistedTo() procedure to access the Chronicle Map instance.

• A concurrent thread or process, currently holding this lock, spends unexpectedly long time (more than 60 seconds) in the context (try-with-resource block) or one of overridden interceptor methods (or MapMethods, or MapEntryOperations, or MapRemoteOperations) while performing an ordinary Map operation or replication. You should either redesign your logic to spend less time in critical sections (recommended) or acquire this lock with tryLock(time, timeUnit) method call, with sufficient time specified.

• Segment(s) in your Chronicle Map are very large, and iteration over them takes more than 60 seconds. In this case you should acquire this lock with tryLock(time, timeUnit) method call, with longer timeout specified.

• This is a dead lock. If you perform multi-key queries, ensure you acquire segment locks in the order (ascending by segmentIndex()), you can find an example here: https://github.com/OpenHFT/Chronicle-Map#multi-key-queries

  at net.openhft.chronicle.hash.impl.BigSegmentHeader.deadLock(BigSegmentHeader.java:71) at net.openhft.chronicle.hash.impl.BigSegmentHeader.updateLock(BigSegmentHeader.java:442) at net.openhft.chronicle.map.impl.CompiledMapIterationContext$UpdateLock.lock(CompiledMapIterationContext.java:807) ... 43 more`

I am running a java application on a RaspberryPi (OS: NAME="Raspbian GNU/Linux" VERSION_ID="11" VERSION="11 (bullseye)")

Java Version: openjdk version "11.0.16" 2022-07-19 OpenJDK Runtime Environment (build 11.0.16+8-post-Raspbian-1deb11u1) OpenJDK Server VM (build 11.0.16+8-post-Raspbian-1deb11u1, mixed mode)

Using chronicle-map version 3.22.9

I got following exception by creating ChronicleMap (Configuration: averageKeySize: 8, averageValueSize: 4194304, maxBloatFactor: 5.0, entries: 10)

java.io.IOException: posix_fallocate() returned 22 at net.openhft.chronicle.hash.impl.util.jna.PosixFallocate.fallocate(PosixFallocate.java:25) at net.openhft.chronicle.hash.impl.VanillaChronicleHash.fallocate(VanillaChronicleHash.java:1128) at net.openhft.chronicle.hash.impl.VanillaChronicleHash.map(VanillaChronicleHash.java:1113) at net.openhft.chronicle.hash.impl.VanillaChronicleHash.createMappedStoreAndSegments(VanillaChronicleHash.java:515) at net.openhft.chronicle.map.ChronicleMapBuilder.createWithNewFile(ChronicleMapBuilder.java:1843) at net.openhft.chronicle.map.ChronicleMapBuilder.createWithFile(ChronicleMapBuilder.java:1741) at net.openhft.chronicle.map.ChronicleMapBuilder.recoverPersistedTo(ChronicleMapBuilder.java:1622) at net.openhft.chronicle.map.ChronicleMapBuilder.createOrRecoverPersistedTo(ChronicleMapBuilder.java:1605) at net.openhft.chronicle.map.ChronicleMapBuilder.createOrRecoverPersistedTo(ChronicleMapBuilder.java:1597) at net.openhft.chronicle.map.ChronicleMapBuilder.createOrRecoverPersistedTo(ChronicleMapBuilder.java:1591)

There is enough space on the volume (51G free), type ext4: /dev/root ext4 59G 5,0G 51G 9% /

The applications breaks with this exception but the file is correctly generated! When i restart the application, everything is working fine.

Do you have any idea why posix_fallocate() returns error code 22, even the file is generated and valid?

I added also a ChronicleHashCorruption.Listener to .createOrRecoverPersistedTo

this listener writes to log:

Message: file=/home/opcua-thinedge/opcua/data/deviceTypeMapping.dat: size-prefixed blob readiness bit is set to NOT_COMPLETE Message: segment headers offset of map at /home/opcua-thinedge/opcua/data/deviceTypeMapping.dat corrupted. stored: 0, should be: 4096 Message: data store size of map at /home/opcua-thinedge/opcua/data/deviceTypeMapping.dat corrupted. stored: 0, should be: 43389504

but this is not true, after the application is stopped, the file is exactly created with the expected size!

Bumps versions-maven-plugin from 2.13.0 to 2.14.2.

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

Bumps xstream from 1.4.19 to 1.4.20.

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

In my use case my Map will contain a Map for both keys and values.

I have run into a weird case where I found two maps that are equal but the size of ObjectOutputStream are not. ( Which ChronicleMap uses under the covers ).

When using a java.util.HashMap my use case works as expected. When I substitute in ChronicleMap, my use case no longer works.

Here is a link to the code that shows the issue: https://github.com/mores/maven-examples/blob/ac6012ca1236ad460f3b3767037531fdb2e3dffd/offHeapMap/src/test/java/org/test/MapTest.java#L76

I am able to reproduce this bug on ubuntu using both 1.8.0_161 and 11.0.17

Bumps third-party-bom from 3.23.0 to 3.23.1.

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.