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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ChronicleMap causes JVM to crash when values are highly variable in size

We've had success so far using ChronicleMap for most things we wanted to use it for, and most data sets have worked just fine. One use case we have is using it as a multimap, covering most of the concerns with doing so. We're using it as a…
Depressio
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Using Map3 and Engine in the same project?

Correct me if I'm wrong, but looks like I will have troubles if I try to use Map3 and Engine in the same project due the same package names? Is there any way it can be done? PS Side note - looks like Engine master branch (at least 'demo' module)…
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Can killing a process corrupt offheap stored data?

Basically subj. In a case of ChronicleMap: if process was killed or failed with OOM error or something else, is there a probability that actual stored data was corrupted and map became not usable any more?
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Does it make sense to store byte values in Map or it will still use 4 bytes?

In Java in-memory there is no difference between byte or int - both will be represented as 4 bytes. Does for Chronicle Map the difference exist, i.e. does Chronicle Map store byte values as 8 bits or still use 32? Same question if byte is an object…
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Fast passing image data between two JVM

I have two Java applications running on the same machine. As there was a requirement for remote connection we implemented the inter-jvm communication via http. We are passing about 10MByte imagedata 100 times a second from one vm to the other. With…
blaster
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How to achieve transaction behaviour with file persisted Chronicle Map

all, I am trying to store time series in Chronicle Map. The series are split into chunks, and every chunk is a separate map entry. I am wondering if anybody knows what is going to happen if JVM exits while an entry is currently being written to the…
user3455810
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ChronicleMap WriteContext usage

Looking into ChronicleMap (2.1.7), and I'm not exactly clear on the proper usage of WriteContext when calling acquireUsingLocked(); The scenario I'm interested in is a function where I need to take 2 actions atomically from the viewpoint of the…
Hoobajoob
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How to use the ChronicleMap as a TimeSeries Database?

I have a backtesting framework that needs to replay tick level market data in order. I am currently using Cassandra where my schema is structured to have all ticks for a single trade date in 1 row. Each column represents a single tick. This makes…
RPJ
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chronicle map - value data types

What's the best way of implementing a chronicle map where the value side is a map or a set? I need data structures similar to the following where I can store multiple versions of some data with a specific id: chronicle-map: String ->…
fitifiti
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Put a on-heap cache in front of chronicle

Wouldnt it make sense to put an on-heap cache (eg guava cache) in front of a persistent off-heap chronicle cache? So, use the chronicle cache when you get a guava cache miss? Thanks
John Caron
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Fast queue on top of Chronicle Map?

We are implementing storage plugin for akka-persistence That means 2 providers, for: queue-like Journal plugin API map-like Snapshot store plugin API Since only Chronicle Map supports multi-node symmetric replication, we eliminate Chronicle Queue…
Andrei Pozolotin
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Strange NPE from Chronicle Map toy code

I'm trying out chronicle map 2.0.0.a, and have setup a toy example map. I'd like to setup a ping-pong example where I set a value in one JVM and read from another. I'm getting a NPE calling map.get in the code below. It's strange because the map…
Eric Lindauer
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Chronicle Map UnsupportedClassVersionError

I'm just trying out ChronicleMap and have run into an issue immediately, an "UnsupportedClassVersionError: Unsupported major.minor version 52.0". I'm using Java 7... should I interpret this error to mean that Chronicle Map is compiled under Java 8? …
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