Questions tagged [chronicle-map]

Chronicle Map is an efficient, low latency in-memory Key Value Store for the JVM with optional persistence to disk.

Chronicle Map is a high performance, off-heap, key-value, in memory, persisted data store. It works like a standard Java map, yet it automatically distributes data between processes. These processes can be both on the same server or across your network. In other words, it's a low-latency, huge data key value store, which can store terabytes of data locally to your process.

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Multimaps in ChronicleMap

There is definitely a disclaimer on ChronicleMap's GitHub about Multimaps in ChronicleMap: Chronicle Map is not... ... No secondary indexes. A multimap. Using a ChronicleMap> as multimap is technically possible, but often leads to…
Depressio
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How to serialise/deserialise long[] value with get/set on random indices using Chronicle Map?

I am new to chronicle-map. I am trying to model an off heap map using chronicle-map where the key is a primitive short and the value is a primitive long array. The max size of the long array value is known for a given map. However I will have…
junkie
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Chronicle Map vs Redis vs Koloboke

We have a system where the same dataset(key-value pairs) is used across 50 servers. The number of updates to this dataset is approximately 1000 per hour and has to be replicated across these 50 servers. We have a master system which receives these…
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Can chronicle-map handle data larger than memory?

I'm a bit confused by how off heap memory works. I have a server that has 32GB ram, and a data set of key-value mappings about 1TB in size. I'm looking for a simple and fast embedded Java database that would allow me to map a key to a value…
user3667125
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Setting max entries on OpenHTF ChronicleMap

I'm playing around with ChronicleSet, which is backed by ChronicleMap. I've done some initial testing, and it's pretty good for our needs. Much more efficient in RAM usage than other solutions, with access time a bit slower, but still pretty fast.…
mjuarez
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OpenHFT ChronicleMap memory alocation and limits

This post would likely be a good candidate for frequently asked questions at OpenHFT. I am playing with ChronicleMap considering it for an idea but having lots of questions. I am sure most junior programmers who are looking into this product have…
Felix
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Observer Pattern for operations performed on Chronicle Map

I am looking forward to use Chronicle Map as a datastore/data cache and intend to share it with other JVM processes running on the same box to reduce memory footprint of each of the other JVM processes else each JVM process will load the same data.…
chauhraj
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how does OpenHFT chronicle map works

Need some info on how chronicle map works, is it like it keeps some key-value pairs in memory and when it overflows a particular threshold of how may value it stores then it overflows the data to disk or it is dependant on memory size, if the size…
Ambuj Jauhari
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Which is a production-ready version of ChronicleMap?

I want to play a bit with ChronicleMap and a bit confused which version should I use in production. 1.* looks like 'released' one, 2.* looks like in alpha stage. I would use release version but from my understanding current documentation refers…
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How does Chronicle map behave when off heap memory is full?

I download some files, and store them off heap using an in-memory chronicle map. I wanted to understand the behaviour of chronicle map, when I exceed the amount of native (off-heap) memory available. I have 2 Questions regarding it: Does the data…
Sarthak Agarwal
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Where exactly does ChronicleMap create the memory mapped file for a persisted map?

I understand ChronicleMap creates a mmap file under the hood but I'm looking through the code and getting a bit lost. Could someone kindly show me where in the code it creates the memory mapped file? I was expecting to see something using a…
trafalgar
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How does the number of entries defined on the builder to a persisted ChronicleMap impact it's ability to scale?

Each example of Chronicle map needs to be given an "entries" size in the builder but I don't understand the impact this value has on a persisted map: ChronicleMap .of(Long.class, Point.class) .averageValueSize(8) …
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Can't close() map in ChronicleMap

According to the documentation, it is good practice to close https://github.com/OpenHFT/Chronicle-Map/blob/master/docs/CM_Tutorial.adoc#close-chroniclemap I can't, for some reason: Map lexicalizationGraph = ChronicleMap …
user8954282
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Using Chronicle Map producing garbage while using Streams API

Today I was experimenting with Chronicle Map. Here is a code sample: package experimental; import net.openhft.chronicle.core.values.IntValue; import net.openhft.chronicle.map.ChronicleMap; import net.openhft.chronicle.values.Values; public class…
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Using ChronicleMap as a key-value database

I would like to use a ChronicleMap as a memory-mapped key-value database (String to byte[]). It should be able to hold up to the order of 100 million entries. Reads/gets will happen much more frequently than writes/puts, with an expected write rate…
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